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Effects of doxorubicin, cisplatin, and tamoxifen on the metabolic profile of human breast cancer MCF-7 cells as determined by 1H HR-MAS NMR Roberta Manzano Maria, Wanessa F. Altei, Heloisa Sobreiro Selistre-de-Araújo, and Luiz Alberto Colnago Biochemistry, Just Accepted Manuscript • DOI: 10.1021/acs.biochem.7b00015 • Publication Date (Web): 05 Apr 2017 Downloaded from http://pubs.acs.org on April 6, 2017

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Title: Effects of doxorubicin, cisplatin, and tamoxifen on the metabolic profile of human breast cancer MCF-7 cells as determined by 1H HR-MAS NMR

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Running Title: Effect of chemotherapy on MCF-7 cells studied by 1H HR-MAS NMR

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Roberta M. Maria1, Wanessa F. Altei2, Heloisa S. Selistre-de-Araujo2, Luiz A. Colnago1*

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1

Embrapa Instrumentação, Rua XV de Novembro, 1452, São Carlos, SP, 13560-970, Brazil; 2

Laboratório de Bioquímica e Biologia Molecular, Departamento de Ciências Fisiológicas, Universidade Federal de São Carlos (UFSCar). Rodovia Washington Luís, km 235, Caixa Postal 676, São Carlos, SP, 13565-905, Brazil.

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Keywords: MCF-7 cells; metabolic profile; doxorubicin; cisplatin; tamoxifen; 1H HRMAS NMR.

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2013/05128-5) and CNPq (grant # 303837/2013-6).

Financial Support: This work was supported by Brazilian agencies FAPESP (grant #

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Corresponding author: *To whom correspondence should be addressed: Luiz Alberto Colnago. [email protected]. Fax: +55 16 21072800 Conflict of Interest: The authors declare that there is no conflict of interest.

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Abstract

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limited studies investigating the way metabolism in breast cancer is affected by chemotherapy. We

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studied, through 1H high-resolution magic angle spinning (HR-MAS) NMR spectroscopy, the metabolic

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profile of human breast cancer MCF-7 control (Con) cells as well as MCF-7 cells treated with tamoxifen

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(Tamo), cisplatin (Cis), and doxorubicin (Doxo). 1H HR-MAS NMR single pulse spectra evidenced

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signals from the cells compounds, including fatty acids (membranes), water-soluble proteins, and

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metabolites. The spectra showed that phosphocholine (i.e., biomarker of breast cancer malignant

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transformation) signals were stronger in Con than in treated cells. Betaine (i.e., the major osmolyte in

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cells) was observed at similar concentrations in MCF-7 control and treated cells, but was absent in non-

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tumor MCF-10A cells. The NMR spectra acquired with Carr-Purcell-Meiboom-Gill (CPMG) pulse

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sequence were used only in qualitative analyses because the signal areas were attenuated according to

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their transverse relaxation time (T2). The CPMG method was used to identify soluble metabolites such as

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organic acids, amino acids, choline and derivatives, taurine, and guanidinoacetate. 1H HR-MAS NMR

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spectroscopy efficiently demonstrated the effects of tamoxifen, cisplatin, and doxorubicin on the

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metabolic profile of MCF-7 cells. The fatty acid, phosphocholine, and choline variations observed by

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single pulse HR-MAS NMR have potential to characterize both responder and non-responder tumors in a

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molecular level.

Doxorubicin, cisplatin, and tamoxifen are part of many chemotherapeutic regimens. However, there are

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Introduction

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with locally advanced breast cancer 1. Doxorubicin, cisplatin, and tamoxifen are among

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the currently used drugs in cancer chemotherapy.

Chemotherapy has improved relapse-free and overall survival times in women

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Doxorubicin corresponds to a class of compounds featuring similar structures,

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the so called anthracyclines 2. The cytostatic effect of this drug may involve several

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mechanisms, such as inhibition of both topoisomerase II and RNA polymerase II 3. The

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formation of reactive oxygen species (ROS), intercalation of doxorubicin into

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chromosomal DNA, and generation of complexes with iron have also been attributed to

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doxorubicin cytostatic mechanism 3. Doxorubicin is considered one of the most efficient

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approaches to treat breast cancer, even though its resistance has led to an unsuccessful

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outcome in many patients 4.

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Cisplatin is another compound used in cancer chemotherapy. It frequently

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promotes a prompt satisfying response 5. Cisplatin is consisted of an inorganic platinum

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complex that inhibits DNA synthesis. However, the resistance of tumor cells to cisplatin

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has been a fundamental problem in tumor management, being responsible for the

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collapse of metastatic cancer treatment 6. Likewise, cisplatin cytotoxicity to regular

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tissues as well as the resistance of cancer cells to this compound impair the therapeutic

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response 7 6.

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Tamoxifen is a nonsteroidal antiestrogen that was first approved by the US Food 8 9

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and Drug administration (FDA) in 1977 for metastatic breast cancer treatment

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chemotherapeutic compound has also been used to reduce the recurrence of primary

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breast cancer as well as to contribute to survival rates as an adjuvant treatment 9 8.

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. This

Tumor biomarkers have been used to establish the disease stage and the efficacy of different drugs and doses

10

. Biomarkers can also be used to discriminate between

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“responders” and “non-responders” 10. In the last decade, metabolomic biomarkers have

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been combined to radiological, genomic, and proteomic ones in order to establish the

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tumor stage. Metabolomics, which stands for the overall assessment of endogenous

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metabolites within a biological system 10, has becoming increasingly used to study the

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effects of anticancer drugs on tumor cells 4.

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NMR spectroscopy and mass spectrometry denote the conventional methods

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used in metabolomic studies. Numerous NMR metabolomic protocols rely upon the

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analysis of tumor extracts that destroy the sample. On the other hand, 1H high-resolution

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magic angle spinning (1H HR-MAS) NMR spectroscopy 11 12 have been use to study the

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metabolic profile of cancer cells and tissues collected through biopsies, without the

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cellular lysis. 1H HR-MAS also provides rapid, highly accurate and reproducible

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analyses requiring straightforward sample preparation 12 13.

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In this work, the effects of doxorubicin, cisplatin, and tamoxifen on metabolic

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profile of intact human breast cancer MCF-7 cells were studied by 1H HR-MAS NMR.

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MCF-7 cells are known to grow in a highly hormone-dependent fashion as well as to

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form well-differentiated tumors in a xenograft animal experimental model

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results confirmed that all drugs have strong effects on the metabolite profile. The major

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effect was the reduction of phosphocholine and fatty acid contents, which are

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considered as biomarkers in breast cancer malignant transformation and as the primary

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material of cell membrane assembly in fast growing cells, respectively.

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. The

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Materials and Methods

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Sample preparation

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MCF-10A (ATCC CRL-10371) (mammary gland-breast non-tumorigenic cell line) and

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MCF-7 cells (ATCC HTB 22) (human breast cancer cell line, estrogen receptor-

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positive) were obtained from the Rio de Janeiro cell collection (BCRJ, Rio de Janeiro,

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RJ, Brazil). MCF-10A was maintained in Dulbecco’s Modified Eagle’s Medium:

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nutrient mixture F-12 (DMEM/F-12, Invitrogen Co., Carlsbad, CA, USA) supplemented

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with 5% fetal horse serum (Thermo Fisher Scientific Inc.), 1% penicillin-streptomycin

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(Thermo Fisher Scientific Inc.), 10 µg/mL bovine insulin (Sigma-Aldrich), 20 ng/mL

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epidermal growth factor (EGF, Sigma-Aldrich), and 0.5 mg/mL hydrocortisone (Sigma-

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Aldrich). All cells were maintained at 37 ºC in a humidified atmosphere comprising

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95% air and 5% CO2.

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MCF-7 cells were grown in Roswell Park Memorial Institute medium (RPMI,

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Thermo Fisher Scientific Inc., Waltham, MA, USA) supplemented with 10% heat-

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inactivated fetal bovine serum (FBS, Thermo Fisher Scientific Inc.). Cells were seeded

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at a density of 1.4 x 106 cells per 75 cm2 cell culture flask and maintained at 37 ºC in a

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humidified incubator containing with 5% CO2 for 72 h to allow cells to attach to the

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flask and become confluent. The medium was removed and subcultures were obtained

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by treating cells with trypsin in phosphate buffered saline (PBS, Sigma Aldrich) for 2

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min. Subsequently, 4 mL of culture medium were added and cells were centrifuged at

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1.200 rpm for 5 min to form pellets. After centrifuging, 10 µl of D2O was added to

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approximately 40 µl of MCF-7 pellet in PBS. This procedure was accomplished in

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triplicate. The cell viability was tested by Trypan Blue exclusion prior to the

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measurements.

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Supplementation of MCF-7 cells

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MCF-7 cells were cultured as described above. After confluence, cells were treated with

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the drugs (i.e., doxorubicin, cisplatin, and tamoxifen), individually, for 24 h. The culture

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medium was supplemented with 1, 70, and 25 µM of doxorubicin, cisplatin, and

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tamoxifen, respectively. We relied upon previous cytotoxicity assays with doxorubicin

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cisplatin, tamoxifen, and doxorubicin were detached from the culture flask using

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trypsin. Once centrifuged, the pellets were resuspended in D2O and newly centrifuged

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prior to NMR analysis. This procedure was carried out in triplicate for each drug.

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1

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Each of the formed pellets was packed into a zirconium HR-MAS rotor containing 20

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µL deuterium oxide with sodium trimethylsilyl-[2,2,3,3-2H4]-1-propionate (TMSP).

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The system was adjusted to 0.00 ppm whereas the spin was set to the magic angle (i.e.,

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54.7 º relative to the magnetic field z direction). 1H-HR-MAS spectroscopy was

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performed at 14.1 T (600 MHz for 1H) and 5 kHz of spinning rate using an AVANCE

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600 BRUKER NMR spectrometer. The spectra were acquired with a 1.5-s presaturation

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pulse, an acquisition time of 4.63 s (32K points), a 4-s recycle delay, and an

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accumulation of 256 transients. Additionally, a Carr-Purcell-Meiboom-Gill (CPMG)

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spin-echo train was employed before data acquisition by means of applying 120 cycles

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separated by echoes of 1.2 ms. The FID signal was multiplied by a 1.0-Hz (0.0025 ppm)

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line broadening as well as a zero filled two-fold for Fourier transform. For automatic

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phase adjustment and baseline correction, the Advanced Chemistry Development

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(ACD) Labs software was applied. Samples were also analyzed using two-dimensional

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(2D) NMR spectroscopy methods, such as COSY (Correlation spectroscopy), 1H-13C-

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HSQC (proton-carbon heteronuclear single-quantum correlation spectroscopy), and 1H-

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13

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HR-MAS spectra of cancer cells were assigned using correlated spectroscopy (2D

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homonuclear and heteronuclear NMR experiments, including COSY, 1H-13C-HSQC,

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and 1H-13C-HMBC). Online databases, such as the Human Metabolome Database

, cisplatin 16, and tamoxifen

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to choose such drug concentrations. Cells treated with

H HR-MAS NMR analyses

C-HMBC (proton-carbon heteronuclear multiple bond correlation spectroscopy). 1H

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(HMDB) and Chenomx were also suitable for assignments. One-dimensional (1D) 1H

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HR-MAS spectra were normalized by correcting baseline offset to zero as well as

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dividing each data point by the sum of all data points, values which were multiplied by

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1000.

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Results

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Figures 1 and 2 show the 1H HR-MAS NMR spectra of human breast cancer

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MCF-7 control cells (Con) and MCF-7 cells treated with tamoxifen (Tamo), cisplatin

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(Cis), and doxorubicin (Doxo). The spectra shown in Figure 1 were acquired with

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single pulse, whereas those presented in Figure 2 were recorded with CPMG pulse

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sequence. The single pulse spectra (Figure 1) show the signals from the cells

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compounds, including fatty acids (membranes) as well as some water-soluble proteins

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and metabolites. The spectra acquired with CPMG sequence (Figure 2) only show the

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sharp signals of the water-soluble metabolites. The CPMG sequence itself has been used

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as a transverse relaxation time (T2) filter (T2 filter) as well as shown to be more efficient

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in attenuating broad (shorter T2) than sharp (longer T2) signals. Therefore, all signals

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presented in Figure 2 were attenuated according to their T2 values as well as the total

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echo time used in the CPMG sequence. Consequently, the CPMG spectra (Figure 2)

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can be used only in qualitative analyses.

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Figures 1A to 1D and 2A to 2D present, respectively, the single pulse and

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CPMG 1H HR-MAS NMR spectra, from 0.5 to 4.5 ppm, of Con (A), Tamo (B), Cis (C),

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and Doxo (D). Figures 1A` to 1D` and 2A` to 2D` show, respectively, the single pulse

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and CPMG 1H HR-MAS NMR spectra of the same samples (i.e., Con (A`), Tamo (B`),

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Cis (C`), and Doxo (D`)), from 5.0 to 10.0 ppm. The vertical axis of spectra A` to D`

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were four-fold magnified. Both single pulse and CPMG 1H HR-MAS NMR spectra of

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the three cultures for each treatment (triplicates) are shown in Figure S1 and Figure

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S2.

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Spectra assignments

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All spectra of Figure 1 show strong, broad peaks overlapped with sharp, weak

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peaks, the latter being assigned to water-soluble metabolites. The broad, strong peaks at

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0.9 (1) and 1.3 ppm (2) have been assigned to methyl and methylene groups of fatty

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acids and proteins, respectively. These peaks also comprised signals from metabolites

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that were better resolved in Figure 2. The broad peak at 5.3 ppm (6) has been assigned

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to the olefinic hydrogens of unsaturated fatty acids. The Con spectrum (Figure 1A) also

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exhibited strong peaks at 3.22 (3), 3.26 (4), and 3.78 ppm (5), which have been assigned

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to phosphocholine, betaine, and guanidinoacetate, respectively. The Tamo spectrum

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(Figure 1B) showed a strong choline peak at 3.20 ppm (7).

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Figure 2 shows the assignment of sixteen metabolites: lactate/threonine (1/2),

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alanine (3), acetate (4), glutamate/glutamine (5/6), acetone (7), creatine (8), choline (9),

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phosphocholine (10), taurine (11), glycine (12), guanidoacetate (13), UTP/UDP/UMP

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(14), tyrosine (15), and phenylalanine (16).

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Figure 1. Single pulse 1H HR-MAS NMR normalized spectra of human breast cancer MCF-7 cells. Control cells (A and A`) and cells treated with Tamo (B and B`) 15, Cis (C and C`) 16, and Doxo (D and D`) 15. The vertical axis of spectra A` to D` were four-fold magnified. The numbers indicate the assignments to methyl (1) and methylene groups (2) of fatty acids and proteins; to phosphocholine (3), betaine (4), and guanidinoacetate (5); and to olefinic hydrogens of unsaturated fatty acids (6), and choline (7). A to D indicate spectra from 0.5 to 4.5 ppm, whereas A` to D` indicate spectra from 5.0 to 10.0 ppm. See also Figure S1.

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Figure 2. 1H HR-MAS NMR spectra of the following breast cancer MCF-7 cells, acquired with CPMG pulse sequence: MCF-7 control cells (A and A`) and MCF-7 cells cells treated with Tamo (B and B`) 15, Cis (C and C`) 16, and Doxo (D and D`) 15. The vertical axis of spectra A` to D` was four-fold magnified. The numbers indicate peaks attributed to lactate/threonine (1/2), alanine (3), acetate (4), glutamate/glutamine (5/6), acetone (7), creatine (8), choline (9), phosphocholine (10), taurine (11), glycine (12), guanidinoacetate (13), UTP/UDP/UMP (14), tyrosine (15), and phenylalanine (16). A to D indicate spectra from 0.5 to 4.5 ppm, whereas A` to D` indicate spectra from 5.0 to 10.0 ppm. See also Figure S2.

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Lactate, threonine, alanine, acetate, glutamate, and glutamine were attributed to

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signals at 1.32 (1), 1.33 (2), 1.47 (3), and 1.91 ppm (4) as well as from 2.0 to 2.5 ppm (5

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and 6), respectively. The signal at 2.2 ppm (7) was assigned to acetone and corroborated

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by the HSQC (1H-13C) signal at 32.86 ppm as well as the HMBC signal at 217.95 ppm

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(C=O). Creatine (8) was assigned to the signal at 3.03 ppm. Choline (9) was assigned to

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the signal at 3.20 ppm (N-CH3) and correlated with HSQC (1H-13C), at 56.64 ppm (N-

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CH3), and with HMBC, at 70.29 ppm (βCH2). Phosphocholine (10) was attributed to the

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signal at 3.22 ppm (N-CH3) with 1H-13C correlations in the HSQC spectrum at 56.62

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ppm (N-CH3) as well as in the HMBC one at 69.19 (βCH2) and 59.63 ppm (C-O).

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Taurine (11) was assigned to the signal at 3.42 ppm (βCH2). Taurine triplets (J=6.47

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Hz) were also clearly separated in the J-resolved spectrum. Glycine (12) was attributed

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to the signal at 3.55 ppm, whereas guanidoacetate (13) was assigned to that at 3.78 ppm.

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UTP/UDP/UMP (14) was assigned to the signals at 5.98 and 7.94 ppm. Finally, tyrosine

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(15) was assigned to the signals at 6.90 and 7.18 ppm, while phenylalanine (16) was

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attributed to those at 7.31, 7.36, and 7.41 ppm. See also Figure S3 and Table S4.

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Effect of chemotherapeutical drugs on the 1H HR-MAS NMR spectra of MCF-7 cells

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The area below the single pulse 1H HR-MAS NMR spectra (Figure 1) show the

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following variations: peak 1 was larger in Tamo>Con>Cis~Doxo; peaks 2 and 3 were

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larger in Con>Tamo>Cis~Doxo; peak 4 was similar in all treatments; peak 5 was larger

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in Con>Cis>Tamo~Doxo; peak 6 was larger in Con~Cis>Tamo~Doxo; and peak 7 was

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larger in Tamo>Con~Cis~Doxo. Therefore, the spectrum of control cells showed the

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highest contents of phosphocholine and unsaturated fatty acids (peaks 3 and 6,

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respectively), which is in accordance with previous reports found in the literature

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Phosphocholine has been considered as a biomarker of breast cancer malignant

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.

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transformation and the growing tumor cells need higher fatty acid contents to form cell

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membranes 18 17.

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The Tamo spectrum shows stronger peaks 1, 2, and 7 than those of Cis and Doxo.

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Larger areas corresponding to methyl (1) and methylene (2) groups as well as smaller

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area assigned to olefinic hydrogens (6) indicate that Tamo either induced the synthesis

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or reduced the uptake of saturated fatty acids. The higher content of choline (7) also

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indicates that this drugs strongly interfered in the phosphastidylcholine metabolism

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(Kennedy pathway) 10 19. The Cis and Doxo spectra suggest that these drugs have strong

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effects on MCF-7 cell metabolism, taking into account that most of the metabolites

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were present at low concentration. The spectra of drug-treated cells showed higher

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content of aromatic compounds such as tyrosine, phenylalanine, UTP/UDP/UMP

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(signal from 6.5 to 10 ppm) than those of control cells (Figure 1A`).

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The cells treated with Cis shows the strongest signals in the aromatic region

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comparing with Doxo and Tamo treatments. Cisplatin is considered as a DNA-

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damaging anticancer drug

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induction of apoptosis, mediated by the activation of various signal transduction

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pathways. For example, the disruption of intracellular calcium homeostasis

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receptor signaling and the activation of mitochondrial pathways 6. Particularly, the

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activation of mitochondrial pathways can explain the higher concentration of

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UMP/UDP/UTP observed in Cisplatin-MCF-7 cells spectra. The significative presence

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of UMP/UDP/UTP can be resulted from Cisplatin intervention in bioenergetics’

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features of mitochondria in MCF-7 cells. Probably, with the influence in many

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biochemical

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metabolism/catabolism of aromatic amino acids, such as phenylalanine and tyrosine.

pathways,

6 20

. Additionally, Cisplatin cause damages in tumors via

Cisplatin

(platinum

compound)

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, death

alter

the

Biochemistry

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The peak 4 at 3.26 ppm, assigned to methyl groups of betaine, was similar in all

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MCF-7 cells samples. However, it was absent in the single pulse 1H HR-MAS NMR

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spectrum of non-tumor MCF-10A cells (inset in Figure 3). In MCF-10A spectrum

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(Figure 3), the broad peak attributed to fatty acids was remarkably weak, whereas

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phosphocholine signal was absent and the major metabolites were glucose, ethanol,

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lactate, acetate, asparagine, and ethanolamine (Maria et al. 2015).

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Betaine is a major osmolyte in cells and plays an essential role in cellular

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protection against environmental stress, including high temperature and osmotic

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imbalance

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presence of betaine in both untreated (control) and treated MCF-7 cells but not in MCF-

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10A cells corroborate the stress condition experienced by tumor cells.

21

. It also regulates cell volume and stabilizes proteins

22

. Therefore, the

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The areas under CPMG 1H HR-MAS NMR signals (Figure 2) of lactate (1),

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threonine (2), alanine (3), and glycine (12) in untreated cells (Con) were found to be

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smaller than in their treated counterparts. Phosphocholine (10) and guanidinoacetate

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(13) were present at higher concentrations in Con and Cis cells, whereas choline (9) and

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glycine (12) contents were higher in Tamo cells (Figure 2B). Doxo cells showed the

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smallest phosphocholine content as shown in single pulse spectrum (Figure 1D).

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Because phosphocholine is considered as a biomarker of breast cancer malignant

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transformation, Doxo was more efficient than Tamo>Cis in reducing the content of this

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metabolite.

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Figures 1A` to 1D` and 2A` to 2D` show that Con cells presented the lowest

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metabolite concentrations, between 5 and 10 ppm. Cis (Figures 1C` and 2C`) showed

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higher concentrations of UTP/UDP/UMP (14), tyrosine (15), phenylalanine (16) than in

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Tamo and Doxo (Figures 1B`-D` and 2B`-D`).

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Figure 3. Single pulse 1H HR-MAS NMR spectrum of non-tumor MCF-10A cells from 0.5 to 4.5 ppm. The inset from 3.1 to 3.3 ppm demonstrates the absence of peak at 3.26 ppm, assigned to betaine.

Discussion

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The higher concentrations of unsaturated fatty acids in Con cells (Figure 1A`)

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than in non-tumor cells (Figure 3), as indicated by peak 6, are in line with the high

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activity of fatty acid synthase in tumor tissue, which in turn is associated with

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proliferation and malignant transformation

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activity supports cancer growth by means of increasing the building blocks for cell

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membranes and for lipids containing molecules involved in cell signaling 23. As a result,

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it would be possible that fatty acids are synthesized de novo in tumor cells themselves

336

24

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fatty acid content (Figures 1A` to D`, peak 6) in cells. Since the broad peaks 1 and 2,

338

which are also related to fatty acids, are stronger in Tamo-treated cells than in those

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treated with Cis and Doxo, this drug is believed to induce the synthesis of saturated

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fatty acids, as suggested by the weak peak 6. It has been observed that the liver of rats,

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upon long-term exposure to tamoxifen, comprised increased contents of choline and

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fatty acids when compared to control cells 25.

17

. Essentially, the fatty acid synthase

. Doxo and Tamo were shown to be more efficient than Cis in reducing unsaturated

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The area of the phosphocholine signal at 3.22 ppm (Figure 1) was reduced in

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cells treated with the three drugs. Because phosphocholine is considered as a breast

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cancer malignant transformation biomarker

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synthesis and, as a consequence, cell invasiveness.

18

, this indicates that all drugs reduced its

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The spectra presented in Figure 2 show that the drugs neither affected the

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concentration of small metabolite molecules in a strong fashion nor restored the high

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glucose level observed in non-tumor MCF-10A cells. It is known that cancer cells

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typically exhibit higher rates of glucose uptake and consumption than non-tumor cells

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26

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anaerobically and form lactate

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observed in MCF-7 cells when compared with MCF-10A cells

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attributed to lactate in untreated cells (Con) was lower than in treated cells (Figure 2).

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This suggests the high disturbance of glycolysis after therapeutic intervention; since

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lactate is the final product of glycolysis, its accumulation implies an increase in

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anaerobic glycolysis.

. Tumor cells, even under normal oxygen concentrations, metabolize glucose 10

. This explains the higher area assigned to lactate 27

. However, the area

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In summary, the NMR spectra acquired with CPMG pulse sequence were used

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only in qualitative analyses because the areas under the signals were attenuated by the

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transverse relaxation time (T2). The CPMG method was used to identify soluble

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metabolites (e.g., organic acids, amino acids, choline and derivatives, taurine, and

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guanidinoacetate).

363

demonstrating the effects of tamoxifen, cisplatin, and doxorubicin on the metabolic

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profile of MCF-7 cells. In conclusion, we demonstrated here that the variations in fatty

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acids, phosphocholine, and choline observed by single pulse HR-MAS NMR

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spectroscopy have potential to characterize the responder and non-responder tumors in

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molecular level.

1

H HR-MAS NMR spectroscopy was remarkably efficient in

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Disclosure of Potential Conflicts of Interest

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No potential conflicts of interest were disclosed.

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Acknowledgements

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We would like to acknowledge the financial support of the Brazilian agencies FAPESP

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(grant # 2013/05128-5) and CNPq (grant # 303837/2013-6).

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FIGURE LEGENDS

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Figure 1. Single pulse 1H HR-MAS NMR normalized spectra of human breast cancer MCF-7 cells. Control cells (A and A`) and cells treated with Tamo (B and B`) 15, Cis (C and C`) 16, and Doxo (D and D`) 15. Spectra ranging from 5.0 to 10.0 ppm were multiply by four. The numbers indicate the assignments to methyl (1) and methylene groups (2) of fatty acids and proteins; to phosphocholine (3), betaine (4), and guanidinoacetate (5); and to olefinic hydrogens of unsaturated fatty acids (6), and choline (7). A to D indicate spectra from 0.5 to 4.5 ppm, whereas A` to D` indicate spectra from 5.0 to 10.0 ppm. See also Figure S1.

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Figure 2. 1H HR-MAS NMR spectra of the following breast cancer MCF-7 cells, acquired with CPMG pulse sequence: MCF-7 control cells (A and A`) and MCF-7 cells cells treated with Tamo (B and B`) 15, Cis (C and C`) 16, and Doxo (D and D`) 15. The vertical axis of spectra A` to D` was four-fold magnified. The numbers indicate peaks attributed to lactate/threonine (1/2), alanine (3), acetate (4), glutamate/glutamine (5/6), acetone (7), creatine (8), choline (9), phosphocholine (10), taurine (11), glycine (12), guanidinoacetate (13), UTP/UDP/UMP (14), tyrosine (15), and phenylalanine (16). A to D indicate spectra from 0.5 to 4.5 ppm, whereas A` to D` indicate spectra from 5.0 to 10.0 ppm. See also Figure S2.

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Figure 3. Single pulse 1H HR-MAS NMR spectrum of non-tumor MCF-10A cells from 0.5 to 4.5 ppm. The inset from 3.1 to 3.3 ppm demonstrates the absence of peak at 3.26 ppm, assigned to betaine.

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Description of the supplementary material - supporting Information:

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- Single pulse 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells

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(Control cells);

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- Single pulse 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells

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treated with tamoxifen;

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- Single pulse 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells

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treated with cisplatin;

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- Single pulse 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells

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treated with doxorubicin;

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- CPMG 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells (Control

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cells).

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- CPMG 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells treated

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with tamoxifen.

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- CPMG 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells treated

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with cisplatin.

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- CPMG 1H HR-MAS NMR normalized triplicate spectra of human breast cancer MCF-7 cells treated

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with doxorubicin.

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- 2D spectra with 1H and 13C (J1) correlations obtained from HSQC experiment.

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- Assignment of 1H and 13C identified from HQSC experiments and software Chenomx.

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