Research ArticleExperimental Studies
Open Access

Recombinant Methioninase Selectively Eliminates Cancer Cells Co-cultured With Normal Fibroblasts Indicating the High-Precision Efficacy of Targeting Methionine Addiction of Cancer

BYUNG MO KANG, QINGHONG HAN, SHUKUAN LI, JIN SOO KIM, KOHEI MIZUTA, YOHEI ASANO, YUTA MIYASHI, MICHAEL BOUVET and ROBERT M. HOFFMAN
Anticancer Research October 2025, 45 (10) 4193-4200; DOI: https://doi.org/10.21873/anticanres.17771

Abstract

Background/Aim: Methionine addiction is a fundamental and general hallmark of cancer and is targeted by methionine restriction. The aim of the present study was to examine whether methionine restriction can eliminate cancer cells co-cultured with normal cells that remain healthy.

Materials and Methods: The IC50 for recombinant methioninase (rMETase) was determined for HC116 colon-cancer cells using the WST-8 viability assay. HCT-116 cells and Hs27 human normal skin fibroblasts were co-cultured and treated with rMETase at the IC50 concentration for HCT-116 cells. Cell morphology and viability were monitored over 16 days via phase-contrast microscopy.

Results: The IC50 for rMETase was 0.46 U/ml for HCT-116 cancer cells. In the untreated control co-cultures, the HCT-116 colon cancer cells overgrew Hs27 normal fibroblasts from day 2. In contrast, rMETase-treated cultures showed elimination of HCT-116 cells by day 8, while Hs27 fibroblasts remained viable and proliferative throughout the experiment.

Conclusion: The differential sensitivity of cancer and normal cells to rMETase at 0.46 U/ml was so extensive that cancer cells were essentially eliminated from the co-cultures while the normal cells remained viable and proliferating. The difference in sensitivity of normal and cancer cells growing together suggests that rMETase selectively and precisely targets methionine addiction of cancer and can be a safe and effective clinical anti-cancer agent.

Keywords:

Introduction

Methionine addiction is a fundamental hallmark of cancer termed the Hoffman effect (1). In several head-to-head comparative studies using PET imaging of cancer patients with [18F]fludeoxyglucose (FDG) and [11C]methionine, the Hoffman effect of methionine addiction has been shown to be generally stronger than glucose addiction of cancer cells termed the Warburg effect (2-4).

Numerous studies have focused on using recombinant methioninase (rMETase), an enzyme that degrades methionine, to effectively target methionine-addicted cancer cells (1, 5, 6). However, whether rMETase can selectively target cancer cells without affecting normal cells is not clearly understood. To address this question in the present study, we conducted a co-culture experiment of cancer and normal cells followed by rMETase treatment aiming to examine the differential sensitivity of cancer and normal cells to rMETase, and to demonstrate directly that the methionine addiction of cancer cells is so extensive that cancer cells can be eliminated from co-cultures with normal cells, while normal cells remain alive and can proliferate.

Materials and Methods

Cell culture. Human colorectal cancer HCT-116 cells and Hs27 normal dermal fibroblasts were obtained from the American Type Culture Collection (ATCC, Manassas, VA, USA). Both cell lines were maintained in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and penicillin/streptomycin at 37°C in a humidified atmosphere with 5% CO2.

Recombinant methioninase production. Recombinant L-methionine α-deamino-γ-mercaptomethane-lyase (rMETase), an enzyme that catalyzes the breakdown of methionine, was produced by fermenting genetically-engineered Escherichia coli containing the methioninase gene, originally derived from Pseudomonas putida (7). Production and purification processes (7) were conducted at AntiCancer Inc. (San Diego, CA, USA).

Determination of the IC50 of rMETase on HCT-116 colon cancer cells. To determine the IC50 of rMETase οn HCT-116 cells, 1,250 cells per well were seeded in 96-well plates. The following day, rMETase was added to six replicate wells at concentrations of 0, 0.125, 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 U/ml. After three days, cell viability was assessed using the WST-8 reagent from the Cell Counting Kit-8 (CCK-8) (Dojindo Laboratory, Kumamoto, Japan). The optical density (OD) at 450 nm was measured with a spectrophotometer (Sunrise™, Tecan Inc. Mannedorf, Switzerland) after addition of the WST-8 reagent to the cell culture (5). The IC50 was calculated from the dose-response curve.

Growth comparison of HCT-116 and Hs27 cells cultured alone with and without rMETase. To compare the growth of HCT-116 and Hs27 cells in response to rMETase, both cell lines were seeded in five 96-well plates, with 1,250 cells per well. Two rows (six wells per row) were assigned to each cell line. Two days after seeding, one row was treated with the rMETase IC50 for HCT-116 cells), and the other was replenished with fresh medium (no rMETase). On days 0, 2, 4, 6, and 8 post-treatment, cell viability was measured using the CCK-8 kit, and the OD at 450 nm was recorded with a spectrophotometer. The average OD from six replicate wells was used to estimate cell number at each time point.

Microscopic analysis of co-cultured HCT-116 and Hs27 cells with and without rMETase. To observe the efficacy of rMETase in co-culture, HCT-116 and Hs27 cells were seeded together in 6-well plates at 3.75×104 cells each (total 7.5×104 cells/well). Two days after seeding, the HCT-116 IC50 for rMETase was added to the treatment wells, while control wells received no rMETase. Phase-contrast microscopy was used to monitor growth status and cell morphology, and images were acquired using the IX71 inverted microscope (Olympus Corporation, Tokyo, Japan).

Results

Efficacy of rMETase on HCT-116 and Hs27 cell growth. The IC50 of rMETase on HCT-116 cell growth was 0.46 U/ml. As shown in Figure 1, 0.46 U/ml of rMETase significantly suppressed HCT-116 cell growth. Cells in untreated wells proliferated steadily, while those treated with rMETase reached a plateau between days 4 and 6 and declined by day 8, indicating growth arrest or loss of viability. In contrast, Hs27 cells showed a minimal response to rMETase, with both treated and untreated groups displaying and comparable growth, and only slight reduction was observed in the treated group at later time points.

Figure 1.
Figure 1.

Growth of HCT-116 and Hs27 cells with or without rMETase treatment. Cell viability was assessed with the CCK-8 assay over 8 days. rMETase (0.46 U/ml) inhibited HCT-116 cell growth, while Hs27 cells showed minimal inhibition. Data represent the mean optical density (OD) at 450 nm after addition of the WST-8 reagent of six replicate wells per group at each time point. Please see the Materials and Methods for details.

Effect of rMETase on HCT-116 and Hs27 cells in co-cultures compared to the untreated co-cultures. Phase-contrast microscopy, at 40-fold magnification, showed morphological differences between co-cultures with and without rMETase (Figure 2). In the absence of rMETase, HCT-116 cells began dominating the co-culture from day 2, rapidly proliferating and overtaking the co-culture. Hs27 fibroblasts appeared as linear arrangements squeezed between between cancer cell clusters, gradually diminishing and becoming barely visible by day 16 (Figure 2A). In contrast, rMETase-treated co-cultures showed sustained Hs27 growth and reduction of HCT-116 cells, which exhibited morphological changes consistent with cell death. By day 8, viable HCT-116 cells were no longer observable, while Hs27 cells remained healthy and proliferative (Figure 2B).

Figure 2.
Figure 2.

Phase-contrast microscopic images of co-cultured HCT-116 and Hs27 cells with and without rMETase treatment (40-fold magnification). (A) Without rMETase, HCT-116 cells rapidly overgrew Hs27 fibroblasts, which appeared as linear arrangements and nearly disappeared by day 16. (B) With 0.46 U/ml rMETase (IC50 for HCT-116 cells), Hs27 cells remained proliferative and dominant, while HCT-116 cells showed signs of cell death and were no longer observed by day 8. Please see the Materials and Methods for details.

At 100-fold magnification on day 14 (Figure 3), untreated co-cultures displayed dense HCT-116 overgrowth, with Hs27 fibroblasts limited to sparse linear arrangements. In rMETase-treated co-cultures, few HCT-116 cells remained, appearing non-viable, while Hs27 fibroblasts predominated. Mitotic Hs27 cells were also observed (black arrows).

Figure 3.
Figure 3.

Phase-contrast microscopic images of co-cultured HCT-116 and Hs27 cells on day 14 with and without rMETase treatment (100-fold magnification). (A) Without rMETase, HCT-116 cells densely covered the surface, with Hs27 fibroblasts remaining only as sparse linear traces. (B) With rMETase, few non-viable HCT-116 cells were observed, while healthy, proliferating Hs27 fibroblasts predominated. Mitotic Hs27 cells are indicated by black arrows. Please see the Materials and Methods for details.

Discussion

The present results show an extensive differential sensitivity of cancer and normal cells to rMETase such that cancer cells were selectively eliminated from co-cultures of cancer and normal cells. This difference in sensitivity of cancer and normal cells to methionine restriction is due to the methionine addiction of cancer cells (5, 8, 9, 11).

Forty years previously we co-cultured normal and cancer cells in homocysteine-containing, methionine-free medium. The addition of chemotherapy drugs was necessary to eliminate the cancer cells in homocysteine-containing, methionine-free medium while maintaining viable proliferating normal cells (10). The present results indicate that rMETase has a much stronger selective effect against cancer cells compared to methionine-free, homocysteine-containing medium.

Methionine restriction is due to overuse of methionine by cancer cells. Although cancer cells make normal or greater amounts of methionine than normal cells they still need external methionine at high levels (11-14). The excess requirement of cancer cells for methionine is due, at least in part, to excess transmethylation reactions in cancer cells including histone lysine methylation (13, 15-18).

Based on these findings, the present study provides direct visual and quantitative evidence that rMETase alone can reverse the growth advantage that methionine-addicted cancer cells have over normal cells. In co-cultures, rMETase rapidly shifted the population dynamics: methionine-addicted HCT-116 cells plateaued and underwent cell death, while methionine-independent Hs27 fibroblasts continued to proliferate and eventually dominated the culture. This indicates that methionine depletion by rMETase not only inhibits the growth of cancer cells but also selectively spares the proliferation of normal cells.

The selective elimination of HCT-116 cells by rMETase became progressively more pronounced from day 8, consistent with the “methionine-depletion catastrophe” previously described in our earlier study (5). In phase-contrast microscopy of co-cultures on day 14, HCT-116 cells overwhelmingly dominated in co-cultures without rMETase, showing extensive overgrowth, whereas in rMETase-treated co-cultures, Hs27 fibroblasts predominated, with visible mitotic figures, and viable HCT-116 cells were scarcely observed (Figure 3). These results demonstrate that rMETase-induced enzymatic methionine depletion is more effective than dietary restriction strategies reported in earlier studies (19, 20).

On a biochemical basis, the increased sensitivity of cancer cells to methionine depletion induced by rMETase may reflect the elevated rate of transmethylation in cancer cells (17, 18), which supports the epigenetic changes required for tumor growth. rMETase reduces extracellular methionine to very low levels, which in turn lowers the production of S adenosylmethionine (SAM) in cancer cells (21), a key molecule used in transmethylation. This limits important methylation-dependent functions in tumors, such as histone modifications (e.g., H3K4 and H3K9 trimethylation) that promote tumor growth and maintain genomic stability (8, 13, 15, 16). In contrast, normal fibroblasts are less affected by methionine depletion because they can utilize endogenously-synthesized methionine and have adequate levels of methionine use for transmethylation (17, 18). Normal as well as cancer cells can regenerate methionine from homocysteine via remethylation, a process that primarily depends on the folate cycle and vitamin B12–dependent methionine synthase (11, 12). However, cancer cells still exhibit a critical dependence on exogenous methionine.

The present study confirms the methionine addiction of HCT-116 colon cancer cells and demonstrates the potential of rMETase as a highly selective and safe anticancer agent. Its ability to selectively eliminate cancer cells while preserving co-cultured normal fibroblasts within the same microenvironment supports its translational feasibility and highlights its favorable safety profile. Unlike conventional chemotherapeutic agents that often harm rapidly dividing normal cells, rMETase targets a specific metabolic vulnerability found only in cancer cells, thereby minimizing off-target toxicity.

Furthermore, our previous findings suggest that rMETase may be particularly effective in combination with other therapies. Previous studies have demonstrated that methionine depletion by rMETase can enhance the efficacy of standard chemotherapeutic agents and immune checkpoint inhibitors (1, 23, 24). By depleting extracellular methionine, rMETase may sensitize methionine-addicted tumors to both cytotoxic chemotherapy and immune-based therapies, potentially enabling dose reductions and minimizing adverse effects. Building on these findings, we plan to compare the responses of cancer and normal cells in co-culture using methionine-free, homocysteine-supplemented media to complete media with rMETase treatment. This will further clarify their differential sensitivity to methionine restriction.

Conclusion

The differential sensitivity of cancer and normal cells to rMETase at 0.46 U/ml was so extensive that cancer cells were effectively eliminated from the co-culture, while normal fibroblasts remained viable and proliferative. This selective effect underscores the potential of rMETase as a precise and cancer-specific therapeutic agent. Its methionine-depleting action may enhance the effectiveness of existing chemo- and immunotherapies, since it targets methionine addiction, which is tightly linked to malignancy (1, 9, 13, 25, 26, 27), and shows the clinical potential of methionine restriction (19, 20, 28-30).

Acknowledgements

This paper is dedicated to the memory of A.R. Moossa, MD, Professor Philip Miles, Sun Lee, MD, Richard W. Erbe, MD, Professor Milton Plesur, Professor Gordon H. Sato, John Littlefield, Professor Li Jiaxi, Masaki Kitajima, MD, Shigeo Yagi, Ph.D., Jack Geller, MD, Joseph R. Bertino, MD, J.A.R. Mead, Ph.D., Eugene P. Frenkel, MD, John Medelsohn, MD, Professor Lev Bergelson, Professor Sheldon Penman, Professor John R. Raper and Joseph Leighton, MD. The Present study was funded by the Robert M. Hoffman Foundation for Cancer Research.

Footnotes

  • Authors’ Contributions

    BMK and RMH conceived and designed the study. QH was responsible for the production of rMETase. BMK performed all experiments and drafted the manuscript. RMH provided critical revisions. JSK, KM, YA, YM, and MB contributed to the critical review of the final manuscript.

  • Conflicts of Interest

    All Authors have no conflicts of interest or financial ties to disclose related to this study.

  • Artificial Intelligence (AI) Disclosure

    No artificial intelligence (AI) tools, including large language models or machine learning software, were used in the preparation, analysis, or presentation of this manuscript.

  • Received June 28, 2025.
  • Revision received July 18, 2025.
  • Accepted July 21, 2025.

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

References

  1. ↵
    1. Abo Qoura L,
    2. Balakin KV,
    3. Hoffman RM,
    4. Pokrovsky VS
    : The potential of methioninase for cancer treatment. Biochim Biophys Acta Rev Cancer 1879(4): 189122, 2024. DOI: 10.1016/j.bbcan.2024.189122
    OpenUrlCrossRef
  2. ↵
    1. Sato M,
    2. Sato T,
    3. Hozumi C,
    4. Han Q,
    5. Mizuta K,
    6. Morinaga S,
    7. Kang BM,
    8. Kobayashi N,
    9. Ichikawa Y,
    10. Nakajima A,
    11. Hoffman RM
    : [11C]Methionine PET vs. [18F]Fluorodeoxyglucose PET whole-body imaging to determine the extent of methionine-addiction compared to glucose-addiction of primary and metastatic cancer of the trunk in patients. Anticancer Res 44(9): 3891-3898, 2024. DOI: 10.21873/anticanres.17216
    OpenUrlAbstract/FREE Full Text
    1. Kubota Y,
    2. Sato T,
    3. Hozumi C,
    4. Han Q,
    5. Aoki Y,
    6. Masaki N,
    7. Obara K,
    8. Tsunoda T,
    9. Hoffman RM
    : Superiority of [(11)C]methionine over [(18)F]deoxyglucose for PET imaging of multiple cancer types due to the methionine addiction of cancer. Int J Mol Sci 24(3): 1935, 2023. DOI: 10.3390/ijms24031935
    OpenUrlCrossRefPubMed
  4. ↵
    1. Kubota Y,
    2. Sato T,
    3. Han Q,
    4. Hozumi C,
    5. Morinaga S,
    6. Mizuta K,
    7. Tsunoda T,
    8. Hoffman RM
    : [(11)C] methionine-PET imaging as a cancer biomarker for methionine addiction and sensitivity to methionine-restriction-based combination chemotherapy. In Vivo 38(1): 253-258, 2024. DOI: 10.21873/invivo.13432
    OpenUrlAbstract/FREE Full Text
  5. ↵
    1. Kang BM,
    2. Han Q,
    3. Mizuta K,
    4. Morinaga S,
    5. Bouvet M,
    6. Hoffman RM
    : Comparison of cell-death kinetics of recombinant methioninase (rMETase)-treated cancer and normal cells: only cancer cells undergo methionine-depletion catastrophe at low rMETase concentrations. Anticancer Res 45(1): 105-111, 2025. DOI: 10.21873/anticanres.17397
    OpenUrlAbstract/FREE Full Text
  6. ↵
    1. Tan Y,
    2. Xu M,
    3. Hoffman RM
    : Broad selective efficacy of recombinant methioninase and polyethylene glycol-modified recombinant methioninase on cancer cells In Vitro. Anticancer Res 30(4): 1041-1046, 2010.
    OpenUrlAbstract/FREE Full Text
  7. ↵
    1. Tan Y,
    2. Xu M,
    3. Tan X,
    4. Tan X,
    5. Wang X,
    6. Saikawa Y,
    7. Nagahama T,
    8. Sun X,
    9. Lenz M,
    10. Hoffman RM
    : Overexpression and large-scale production of recombinantl-methionine-α-deamino-γ-mercaptomethane-lyase for novel anticancer therapy. Protein Expr Purif 9(2): 233-245, 1997. DOI: 10.1006/prep.1996.0700
    OpenUrlCrossRefPubMed
  8. ↵
    1. Wang Z,
    2. Yip LY,
    3. Lee JHJ,
    4. Wu Z,
    5. Chew HY,
    6. Chong PKW,
    7. Teo CC,
    8. Ang HY,
    9. Peh KLE,
    10. Yuan J,
    11. Ma S,
    12. Choo LSK,
    13. Basri N,
    14. Jiang X,
    15. Yu Q,
    16. Hillmer AM,
    17. Lim WT,
    18. Lim TKH,
    19. Takano A,
    20. Tan EH,
    21. Tan DSW,
    22. Ho YS,
    23. Lim B,
    24. Tam WL
    : Methionine is a metabolic dependency of tumor-initiating cells. Nat Med 25(5): 825-837, 2019. DOI: 10.1038/s41591-019-0423-5
    OpenUrlCrossRefPubMed
  9. ↵
    1. Lin DW,
    2. Carranza FG,
    3. Borrego S,
    4. Lauinger L,
    5. Dantas de Paula L,
    6. Pulipelli HR,
    7. Andronicos A,
    8. Hertel KJ,
    9. Kaiser P
    : Nutrient control of splice site selection contributes to methionine addiction of cancer. Mol Metab 93: 102103, 2025. DOI: 10.1016/j.molmet.2025.102103
    OpenUrlCrossRefPubMed
  10. ↵
    1. Stern PH,
    2. Hoffman RM
    : Enhanced in vitro selective toxicity of chemotherapeutic agents for human cancer cells based on a metabolic defect. J Natl Cancer Inst 76(4): 629-639, 1986. DOI: 10.1093/jnci/76.4.629
    OpenUrlCrossRefPubMed
  11. ↵
    1. Hoffman RM,
    2. Erbe RW
    : High in vivo rates of methionine biosynthesis in transformed human and malignant rat cells auxotrophic for methionine. Proc Natl Acad Sci U S A 73(5): 1523-1527, 1976. DOI: 10.1073/pnas.73.5.1523
    OpenUrlAbstract/FREE Full Text
  12. ↵
    1. Sullivan MR,
    2. Darnell AM,
    3. Reilly MF,
    4. Kunchok T,
    5. Joesch-Cohen L,
    6. Rosenberg D,
    7. Ali A,
    8. Rees MG,
    9. Roth JA,
    10. Lewis CA,
    11. Vander Heiden MG
    : Methionine synthase is essential for cancer cell proliferation in physiological folate environments. Nat Metab 3(11): 1500-1511, 2021. DOI: 10.1038/s42255-021-00486-5
    OpenUrlCrossRef
  13. ↵
    1. Yamamoto J,
    2. Inubushi S,
    3. Han Q,
    4. Tashiro Y,
    5. Sugisawa N,
    6. Hamada K,
    7. Aoki Y,
    8. Miyake K,
    9. Matsuyama R,
    10. Bouvet M,
    11. Clarke SG,
    12. Endo I,
    13. Hoffman RM
    : Linkage of methionine addiction, histone lysine hypermethylation, and malignancy. iScience 25(4): 104162, 2022. DOI: 10.1016/j.isci.2022.104162
    OpenUrlCrossRefPubMed
  14. ↵
    1. Kaiser P
    : Methionine dependence of cancer. Biomolecules 10(4): 568, 2020. DOI: 10.3390/biom10040568
    OpenUrlCrossRefPubMed
  15. ↵
    1. Yamamoto J,
    2. Aoki Y,
    3. Inubushi S,
    4. Han Q,
    5. Hamada K,
    6. Tashiro Y,
    7. Miyake K,
    8. Matsuyama R,
    9. Bouvet M,
    10. Clarke SG,
    11. Endo I,
    12. Hoffman RM
    : Extent and instability of trimethylation of histone H3 lysine increases with degree of malignancy and methionine addiction. Cancer Genomics Proteomics 19(1): 12-18, 2022. DOI: 10.21873/cgp.20299
    OpenUrlAbstract/FREE Full Text
  16. ↵
    1. Aoki Y,
    2. Tome Y,
    3. Han Q,
    4. Yamamoto J,
    5. Hamada K,
    6. Masaki N,
    7. Bouvet M,
    8. Nishida K,
    9. Hoffman RM
    : Histone H3 lysine-trimethylation markers are decreased by recombinant methioninase and increased by methotrexate at concentrations which inhibit methionine-addicted osteosarcoma cell proliferation. Biochem Biophys Rep 28: 101177, 2021. DOI: 10.1016/j.bbrep.2021.101177
    OpenUrlCrossRefPubMed
  17. ↵
    1. Stern PH,
    2. Hoffman RM
    : Elevated overall rates of transmethylation in cell lines from diverse human tumors. In Vitro 20(8): 663-670, 1984. DOI: 10.1007/bf02619617
    OpenUrlCrossRefPubMed
  18. ↵
    1. Judde JG,
    2. Ellis M,
    3. Frost P
    : Biochemical analysis of the role of transmethylation in the methionine dependence of tumor cells. Cancer Res 49(17): 4859-4865, 1989.
    OpenUrlAbstract/FREE Full Text
  19. ↵
    1. Epner DE,
    2. Morrow S,
    3. Wilcox M,
    4. Houghton JL
    : Nutrient intake and nutritional indexes in adults with metastatic cancer on a phase I clinical trial of dietary methionine restriction. Nutr Cancer 42(2): 158-166, 2002. DOI: 10.1207/S15327914NC422_2
    OpenUrlCrossRefPubMed
  20. ↵
    1. Thivat E,
    2. Farges MC,
    3. Bacin F,
    4. D’Incan M,
    5. Mouret-Reynier MA,
    6. Cellarier E,
    7. Madelmont JC,
    8. Vasson MP,
    9. Chollet P,
    10. Durando X
    : Phase II trial of the association of a methionine-free diet with cystemustine therapy in melanoma and glioma. Anticancer Res 29(12): 5235-5240, 2009.
    OpenUrlAbstract/FREE Full Text
  21. ↵
    1. Coalson DW,
    2. Mecham JO,
    3. Stern PH,
    4. Hoffman RM
    : Reduced availability of endogenously synthesized methionine for S-adenosylmethionine formation in methionine-dependent cancer cells. Proc Natl Acad Sci USA 79(14): 4248-4251, 1982. DOI: 10.1073/pnas.79.14.4248
    OpenUrlAbstract/FREE Full Text
    1. Yamamoto J,
    2. Han Q,
    3. Inubushi S,
    4. Sugisawa N,
    5. Hamada K,
    6. Nishino H,
    7. Miyake K,
    8. Kumamoto T,
    9. Matsuyama R,
    10. Bouvet M,
    11. Endo I,
    12. Hoffman RM
    : Histone methylation status of H3K4me3 and H3K9me3 under methionine restriction is unstable in methionine-addicted cancer cells, but stable in normal cells. Biochem Biophys Res Commun 533(4): 1034-1038, 2020. DOI: 10.1016/j.bbrc.2020.09.108
    OpenUrlCrossRefPubMed
  23. ↵
    1. Kubota Y,
    2. Han Q,
    3. Aoki Y,
    4. Masaki N,
    5. Obara K,
    6. Hamada K,
    7. Hozumi C,
    8. Wong ACW,
    9. Bouvet M,
    10. Tsunoda T,
    11. Hoffman RM
    : Synergy of combining methionine restriction and chemotherapy: the disruptive next generation of cancer treatment. Cancer Diagn Progn 3(3): 272-281, 2023. DOI: 10.21873/cdp.10212
    OpenUrlCrossRefPubMed
  24. ↵
    1. Mizuta K,
    2. Kang BM,
    3. Han Q,
    4. Kubota Y,
    5. Morinaga S,
    6. Sato M,
    7. Bouvet M,
    8. Tome Y,
    9. Nishida K,
    10. Hoffman RM
    : Expression of PD-L1 is increased by methionine restriction using recombinant methioninase in human colorectal cancer cells. Cancer Genomics Proteomics 21(4): 395-398, 2024. DOI: 10.21873/cgp.20457
    OpenUrlAbstract/FREE Full Text
  25. ↵
    1. Yamamoto J,
    2. Aoki Y,
    3. Han Q,
    4. Sugisawa N,
    5. Sun YU,
    6. Hamada K,
    7. Nishino H,
    8. Inubushi S,
    9. Miyake K,
    10. Matsuyama R,
    11. Bouvet M,
    12. Endo I,
    13. Hoffman RM
    : Reversion from methionine addiction to methionine independence results in loss of tumorigenic potential of highly-malignant lung-cancer cells. Anticancer Res 41(2): 641-643, 2021. DOI: 10.21873/anticanres.14815
    OpenUrlAbstract/FREE Full Text
  26. ↵
    1. Hoffman RM,
    2. Jacobsen SJ,
    3. Erbe RW
    : Reversion to methionine independence in simian virus 40-transformed human and malignant rat fibroblasts is associated with altered ploidy and altered properties of transformation. Proc Natl Acad Sci USA 76(3): 1313-1317, 1979. DOI: 10.1073/pnas.76.3.1313
    OpenUrlAbstract/FREE Full Text
  27. ↵
    1. Aoki Y,
    2. Han Q,
    3. Tome Y,
    4. Yamamoto J,
    5. Kubota Y,
    6. Masaki N,
    7. Obara K,
    8. Hamada K,
    9. Wang JD,
    10. Inubushi S,
    11. Bouvet M,
    12. Clarke SG,
    13. Nishida K,
    14. Hoffman RM
    : Reversion of methionine addiction of osteosarcoma cells to methionine independence results in loss of malignancy, modulation of the epithelial-mesenchymal phenotype and alteration of histone-H3 lysine-methylation. Front Oncol 12: 1009548, 2022. DOI: 10.3389/fonc.2022.1009548
    OpenUrlCrossRefPubMed
  28. ↵
    1. Gao X,
    2. Sanderson SM,
    3. Dai Z,
    4. Reid MA,
    5. Cooper DE,
    6. Lu M,
    7. Richie JP Jr.,
    8. Ciccarella A,
    9. Calcagnotto A,
    10. Mikhael PG,
    11. Mentch SJ,
    12. Liu J,
    13. Ables G,
    14. Kirsch DG,
    15. Hsu DS,
    16. Nichenametla SN and
    17. Locasale JW
    : Dietary methionine influences therapy in mouse cancer models and alters human metabolism. Nature 572(7769): 397-401, 2019. PMID: 31367041. DOI: 10.1038/s41586-019-1437-3
    OpenUrlCrossRefPubMed
    1. Han Q,
    2. Tan Y and
    3. Hoffman RM
    : Oral dosing of recombinant methioninase is associated with a 70% drop in PSA in a patient with bone-metastatic prostate cancer and 50% reduction in circulating methionine in a high-stage ovarian cancer patient. Anticancer Res 40(5): 2813-2819, 2020. PMID: 32366428. DOI: 10.21873/anticanres.14254
    OpenUrlAbstract/FREE Full Text
  30. ↵
    1. Kubota Y,
    2. Han Q,
    3. Masaki N,
    4. Hozumi C,
    5. Hamada K,
    6. Aoki Y,
    7. Obara K,
    8. Tsunoda T,
    9. Hoffman RM
    : Elimination of axillary-lymph-node metastases in a patient with invasive lobular breast cancer treated by first-line neo-adjuvant chemotherapy combined with methionine restriction. Anticancer Res 42(12): 5819-5823, 2022. DOI: 10.21873/anticanres.16089
    OpenUrlAbstract/FREE Full Text
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Recombinant Methioninase Selectively Eliminates Cancer Cells Co-cultured With Normal Fibroblasts Indicating the High-Precision Efficacy of Targeting Methionine Addiction of Cancer
BYUNG MO KANG, QINGHONG HAN, SHUKUAN LI, JIN SOO KIM, KOHEI MIZUTA, YOHEI ASANO, YUTA MIYASHI, MICHAEL BOUVET, ROBERT M. HOFFMAN
Anticancer Research Oct 2025, 45 (10) 4193-4200; DOI: 10.21873/anticanres.17771
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