Pharmacologic Tumor PDL1 Depletion with Cefepime or Ceftazidime Promotes DNA Damage and Sensitivity to DNA-Damaging Agents
<p><b>Cefepime depletes tumor PDL1 in multiple distinct tumor cell lines.</b> (<b>A</b>) Schematic of high-throughput drug screen used to identify pharmacologic PDL1-depleting agents (PDDs). (<b>B</b>) Immunoblots of PDL1 and the loading control vinculin (VINC) in B16, ID8agg, and GL261 cells treated with 80 μM cefepime for indicated times. GL261 cells were treated with DMSO (veh), 250 nM rabusertib (rab), or 80 μM cefepime (cef) for 48 h. Cefepime was replenished daily.</p> "> Figure 2
<p><b>Cefepime induces DNA damage and sensitizes to DNA-damaging agents.</b> (<b>A</b>) Immunoblot for γH2AX, PDL1, and vinculin loading control (VINC) of ID8agg cells treated with DMSO vehicle (veh), rabusertib (rab) as indicated, 80 μM cefepime (cef), or combination (combo) for 72 h. (<b>B</b>) MTT viability assay of GL261 cells treated with 100 μM cefepime (cef) or vehicle (DMSO) in combination with indicated concentrations of temozolamide (TMZ). <span class="html-italic">p</span> value by two-way ANOVA. (<b>C</b>) MTT viability of T24 cells treated with 80 μM cefepime or vehicle (DMSO) in combination with indicated concentrations of gemcitabine (gem). <span class="html-italic">p</span> value by two-way ANOVA. (<b>D</b>) MTT viability of T24 cells treated with the Chk1i prexasertib (prex) at indicated concentrations combined with DMSO vehicle or 80 μM cefepime. <span class="html-italic">p</span> value by two-way ANOVA. (<b>E</b>) MTT viability of ID8agg cells treated with rabusertib (rab) at indicated concentrations in combination with DMSO or 80 μM cefepime. <span class="html-italic">p</span> value by two-way ANOVA. Drugs were not replenished in these assays.</p> "> Figure 3
<p><b>Cefepime-induced DNA damage and sensitivity to DNA-damaging agents is tumor PDL1-dependent with ROS contributions in distinct lines.</b> (<b>A</b>) MTT viability in PDL1<sup>KO</sup> ID8agg cells treated with 80 μM cefepime (cef) or DMSO (veh) in combination with indicated concentrations of rabusertib (rab). <span class="html-italic">p</span> value by two-way ANOVA. (<b>B</b>) Immunoblots of T24, ID8agg, and B16 cells treated with 80 μM cefepime and/or 0.5 mM N-acetyl-L-cysteine (NAC) for γH2AX, PDL1, and loading control vinculin (VINC) (48 h incubation).</p> "> Figure 4
<p><b>Cefepime elicits PDL1-dependent rabusertib sensitivity in vivo and skews towards TH1.</b> (<b>A</b>) Survival of NSG mice (<span class="html-italic">n</span> = 5 per group) challenged with T24 cells. Mice were treated beginning Day 7 with vehicle (veh), 200 mg/kg cefepime (cef), and/or 2.5 mg/kg rabusertib (rab) daily. <span class="html-italic">p</span> value by log-rank test. (<b>B</b>) Tumor growth in WT mice challenged with B16 cells treated with vehicle, 5 mg/kg rabusertib daily, and/or 200 mg/kg cefepime twice daily beginning Day 3 post-challenge. <span class="html-italic">p</span> value by two-way ANOVA. (<b>C</b>) Flow cytometry analyses of immune populations in tumors derived from vehicle-, rabusertib-, cefepime-, and combination (combo)-treated mice. <span class="html-italic">p</span> values by unpaired <span class="html-italic">t</span> test.</p> "> Figure 5
<p><b>Cefepime promotes tumor STING activation.</b> (<b>A</b>) Immunoblot for STING, phospho-TBK1 (pTBK1), and loading control vinculin (VINC) of B16 cells treated with DMSO or 80 μM cefepime (cef) for 24 h. (<b>B</b>) Western blot for STING, pTBK1, total TBK1, and loading control vinculin in B16 cells treated with 80 μM cefepime and/or 0.5 mM N-acetyl-L-cysteine (NAC) for 48 h. (<b>C</b>) Immunoblot for targets as in (<b>B</b>) in ID8agg cells treated with 80 μM cefepime and/or 0.5 mM N-acetyl-L-cysteine for 48 h. (<b>D</b>) RT-qPCR assessment of normalized gene expression in B16 cells treated as in (<b>B</b>). <span class="html-italic">p</span> values by unpaired <span class="html-italic">t</span> test. (<b>E</b>) RT-qPCR assessment of normalized gene expression in ID8agg cells treated as in (<b>C</b>). <span class="html-italic">p</span> values by unpaired <span class="html-italic">t</span> test.</p> "> Figure 6
<p><b>Cefepime regulates tumor PDL1 post-translationally.</b> (<b>A</b>) RT-qPCR assessment of normalized <span class="html-italic">Cd274</span> gene expression of B16 and ID8agg cells treated with DMSO (veh) or 80 μM cefepime (cef) for 48 and 24 h, respectively. (<b>B</b>) Western blot of ID8agg cells treated with 0.2 μM mg132 for final 6 h, 100 nM bafilomycin A1 (BafA1) for final 6 h, and/or 80 μM cefepime for 48 h for PDL1 and loading control vinculin (VINC).</p> "> Figure 7
<p><b>Tumor PDL1depletion effects of cefepime are likely independent of the β-lactam ring.</b> (<b>A</b>) Immunoblot of PDL1 and loading control vinculin (VINC) of ID8agg cells treated with DMSO (veh) or 80 μM of β-lactam antibiotics cefepime (cef), ceftazidime (cz), penicillin G (pen G), cefazolin (cefaz), ceftriaxone (ceftri), and the carbapenem meropenem (mero) for 48 h. Drugs were replenished daily. (<b>B</b>) Immunoblot for PDL1 and loading control vinculin of ID8agg and B16 cells treated with ceftazidime for indicated time points, replenished daily. (<b>C</b>) Western blot for γH2AX, PDL1, and loading control vinculin of ID8agg treated with DMSO, 2.5 μM rabusertib (rab), 80 μM ceftazidime, or combination for 72 h. (<b>D</b>) Immunoblot of B16 cells treated with DMSO or ceftazidime for 24 h for STING, phospho-TBK1, and loading control vinculin. (<b>E</b>) MTT viability of U251 cells treated with 80 μM of β-lactam antibiotics cefepime, ceftazidime, penicillin G, cefazolin, ceftriaxone, and the carbapenem meropenem for 96 h. <span class="html-italic">p</span> values by unpaired <span class="html-italic">t</span> test. (<b>F</b>) MTT viability assay of ID8agg cells treated with rabusertib (rab) with DMSO or 80 μM ceftazidime for 96 h. <span class="html-italic">p</span> value by two-way ANOVA. (<b>G</b>) MTT viability of PDL1<sup>KO</sup> ID8agg cells treated with rabusertib, DMSO, or 80 μM ceftazidime for 96 h. <span class="html-italic">p</span> value by two-way ANOVA.</p> "> Figure 8
<p><b>PDDs phenocopy additional genetic tumor-PDL1-depletion effects.</b> (<b>A</b>) RT-qPCR for normalized stemness-associated gene expression (<span class="html-italic">Pouf51</span>, <span class="html-italic">Sox2</span>, <span class="html-italic">Nanog</span>, <span class="html-italic">c-Myc)</span> of ID8agg cells treated with DMSO (veh) or 80 μM cefepime (cef) for 48 h, replenished daily. <span class="html-italic">p</span> values by way of unpaired <span class="html-italic">t</span> test. (<b>B</b>) Immunoblot for phospho-S6, total S6, LC3A/B, PDL1, and loading control vinculin (VINC) in ID8agg cells cultured and replenished daily with 80 μM cefepime (cef) or ceftazidime (cz) daily for two days.</p> ">
Abstract
:1. Introduction
2. Results
2.1. Cefepime Is a Pharmacologic Tumor PDL1-Depleting Drug
2.2. Cefepime Induces DNA Damage and Sensitizes to DNA-Damaging Agents In Vitro
2.3. Cefepime-Induced DNA Damage and Synthetic Lethality Is Tumor-Cell-PDL1-Dependent and Can Include ROS Contributions
2.4. Cefepime Improves Rabusertib Sensitivity In Vivo and Skews towards TH1-Polarized Immunity
2.5. PDDs Promote Tumor STING Activation
2.6. Cefepime Regulates Tumor PDL1 Post-Translationally
2.7. The Cefepime β-Lactam Ring Appears Dispensable for PDD and Cytotoxic Effects
2.8. PDDs Phenocopy Other Genetic Tumor-PDL1KO Outcomes
3. Discussion
4. Materials and Methods
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
- Hayashi, H.; Nakagawa, K. Combination therapy with PD-1 or PD-L1 inhibitors for cancer. Int. J. Clin. Oncol. 2020, 25, 818–830. [Google Scholar] [CrossRef] [PubMed]
- Topalian, S.L.; Taube, J.M.; Pardoll, D.M. Neoadjuvant checkpoint blockade for cancer immunotherapy. Science 2020, 367, 6477. [Google Scholar] [CrossRef] [PubMed]
- Tang, H.; Liang, Y.; Anders, R.A.; Taube, J.M.; Qiu, X.; Mulgaonkar, A.; Liu, X.; Harrington, S.M.; Guo, J.; Xin, Y.; et al. PD-L1 on host cells is essential for PD-L1 blockade-mediated tumor regression. J. Clin. Investig. 2018, 128, 580–588. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Rizvi, N.A.; Cho, B.C.; Reinmuth, N.; Lee, K.H.; Luft, A.; Ahn, M.J.; van den Heuvel, M.M.; Cobo, M.; Vicente, D.; Smolin, A.; et al. Durvalumab with or without Tremelimumab vs Standard Chemotherapy in First-line Treatment of Metastatic Non-Small Cell Lung Cancer: The MYSTIC Phase 3 Randomized Clinical Trial. JAMA Oncol. 2020, 6, 661–674. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Rajan, A.; Heery, C.R.; Thomas, A.; Mammen, A.L.; Perry, S.; O’Sullivan Coyne, G.; Guha, U.; Berman, A.; Szabo, E.; Madan, R.A.; et al. Efficacy and tolerability of anti-programmed death-ligand 1 (PD-L1) antibody (Avelumab) treatment in advanced thymoma. J. Immunother. Cancer 2019, 7, 269. [Google Scholar] [CrossRef] [PubMed]
- Kornepati, A.V.R.; Vadlamudi, R.K.; Curiel, T.J. Programmed death ligand 1 signals in cancer cells. Nat. Rev. Cancer 2022, 22, 174–189. [Google Scholar] [CrossRef] [PubMed]
- Clark, C.A.; Gupta, H.B.; Sareddy, G.; Pandeswara, S.; Lao, S.; Yuan, B.; Drerup, J.M.; Padron, A.; Conejo-Garcia, J.; Murthy, K.; et al. Tumor-Intrinsic PD-L1 Signals Regulate Cell Growth, Pathogenesis, and Autophagy in Ovarian Cancer and Melanoma. Cancer Res. 2016, 76, 6964–6974. [Google Scholar] [CrossRef] [Green Version]
- Zhang, D.; Reyes, R.M.; Osta, E.; Kari, S.; Gupta, H.B.; Padron, A.S.; Kornepati, A.V.R.; Kancharla, A.; Sun, X.; Deng, Y.; et al. Bladder cancer cell-intrinsic PD-L1 signals promote mTOR and autophagy activation that can be inhibited to improve cytotoxic chemotherapy. Cancer Med. 2021, 10, 2137–2152. [Google Scholar] [CrossRef]
- Wu, X.; Li, Y.; Liu, X.; Chen, C.; Harrington, S.M.; Cao, S.; Xie, T.; Orzechowski, A.; Pham, T.; Mansfield, A.S.; et al. Targeting B7-H1 (PD-L1) sensitizes cancer cells to chemotherapy. Heliyon 2018, 4, e01039. [Google Scholar] [CrossRef] [Green Version]
- Peng, S.; Wang, R.; Zhang, X.; Ma, Y.; Zhong, L.; Li, K.; Nishiyama, A.; Arai, S.; Yano, S.; Wang, W. EGFR-TKI resistance promotes immune escape in lung cancer via increased PD-L1 expression. Mol. Cancer 2019, 18, 165. [Google Scholar] [CrossRef]
- Gao, Y.; Nihira, N.T.; Bu, X.; Chu, C.; Zhang, J.; Kolodziejczyk, A.; Fan, Y.; Chan, N.T.; Ma, L.; Liu, J.; et al. Acetylation-dependent regulation of PD-L1 nuclear translocation dictates the efficacy of anti-PD-1 immunotherapy. Nat. Cell. Biol. 2020, 22, 1064–1075. [Google Scholar] [CrossRef] [PubMed]
- Hou, J.; Zhao, R.; Xia, W.; Chang, C.W.; You, Y.; Hsu, J.M.; Nie, L.; Chen, Y.; Wang, Y.C.; Liu, C.; et al. PD-L1-mediated gasdermin C expression switches apoptosis to pyroptosis in cancer cells and facilitates tumour necrosis. Nat. Cell Biol. 2020, 22, 1264–1275. [Google Scholar] [CrossRef] [PubMed]
- Gupta, H.B.; Clark, C.A.; Yuan, B.; Sareddy, G.; Pandeswara, S.; Padron, A.S.; Hurez, V.; Conejo-Garcia, J.; Vadlamudi, R.; Li, R.; et al. Tumor cell-intrinsic PD-L1 promotes tumor-initiating cell generation and functions in melanoma and ovarian cancer. Signal Transduct. Target. Ther. 2016, 1, 1–9. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Kornepati, A.V.R.; Boyd, J.T.; Murray, C.E.; Saifetiarova, J.; Avalos, B.d.l.P.; Rogers, C.M.; Bai, H.; Padron, A.S.; Liao, Y.; Ontiveros, C.; et al. Tumor-intrinsic programmed death-ligand 1 promotes DNA repair in distinct cancers and can suppress PARP inhibitor synthetic lethality. Cancer Res. 2022. online ahead of print. [Google Scholar]
- Chapman, T.M.; Perry, C.M. Cefepime: A review of its use in the management of hospitalized patients with pneumonia. Am. J. Respir. Med. 2003, 2, 75–107. [Google Scholar] [CrossRef]
- von der Maase, H.; Sengelov, L.; Roberts, J.T.; Ricci, S.; Dogliotti, L.; Oliver, T.; Moore, M.J.; Zimmermann, A.; Arning, M. Long-term survival results of a randomized trial comparing gemcitabine plus cisplatin, with methotrexate, vinblastine, doxorubicin, plus cisplatin in patients with bladder cancer. J. Clin. Oncol. 2005, 23, 4602–4608. [Google Scholar] [CrossRef]
- Stupp, R.; Mason, W.P.; van den Bent, M.J.; Weller, M.; Fisher, B.; Taphoorn, M.J.; Belanger, K.; Brandes, A.A.; Marosi, C.; Bogdahn, U.; et al. Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. N. Engl. J. Med. 2005, 352, 987–996. [Google Scholar] [CrossRef]
- Qiu, Z.; Oleinick, N.L.; Zhang, J. ATR/CHK1 inhibitors and cancer therapy. Radiother. Oncol. 2018, 126, 450–464. [Google Scholar] [CrossRef]
- Sato, H.; Jeggo, P.A.; Shibata, A. Regulation of programmed death-ligand 1 expression in response to DNA damage in cancer cells: Implications for precision medicine. Cancer Sci. 2019, 110, 3415–3423. [Google Scholar] [CrossRef] [Green Version]
- Sen, T.; Rodriguez, B.L.; Chen, L.; Corte, C.M.D.; Morikawa, N.; Fujimoto, J.; Cristea, S.; Nguyen, T.; Diao, L.; Li, L.; et al. Targeting DNA Damage Response Promotes Antitumor Immunity through STING-Mediated T-cell Activation in Small Cell Lung Cancer. Cancer Discov. 2019, 9, 646–661. [Google Scholar] [CrossRef] [Green Version]
- Kalghatgi, S.; Spina, C.S.; Costello, J.C.; Liesa, M.; Morones-Ramirez, J.R.; Slomovic, S.; Molina, A.; Shirihai, O.S.; Collins, J.J. Bactericidal antibiotics induce mitochondrial dysfunction and oxidative damage in Mammalian cells. Sci. Transl. Med. 2013, 5, 192ra185. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Helmink, B.A.; Khan, M.A.W.; Hermann, A.; Gopalakrishnan, V.; Wargo, J.A. The microbiome, cancer, and cancer therapy. Nat. Med. 2019, 25, 377–388. [Google Scholar] [CrossRef] [PubMed]
- Elkrief, A.; Derosa, L.; Kroemer, G.; Zitvogel, L.; Routy, B. The negative impact of antibiotics on outcomes in cancer patients treated with immunotherapy: A new independent prognostic factor? Ann. Oncol. 2019, 30, 1572–1579. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Sallusto, F.; Lenig, D.; Mackay, C.R.; Lanzavecchia, A. Flexible programs of chemokine receptor expression on human polarized T helper 1 and 2 lymphocytes. J. Exp. Med. 1998, 187, 875–883. [Google Scholar] [CrossRef] [PubMed]
- Decout, A.; Katz, J.D.; Venkatraman, S.; Ablasser, A. The cGAS-STING pathway as a therapeutic target in inflammatory diseases. Nat. Rev. Immunol. 2021, 21, 548–569. [Google Scholar] [CrossRef] [PubMed]
- Liang, J.; Wang, L.; Wang, C.; Shen, J.; Su, B.; Marisetty, A.L.; Fang, D.; Kassab, C.; Jeong, K.J.; Zhao, W.; et al. Verteporfin Inhibits PD-L1 through Autophagy and the STAT1-IRF1-TRIM28 Signaling Axis, Exerting Antitumor Efficacy. Cancer Immunol. Res. 2020, 8, 952–965. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Lim, S.O.; Li, C.W.; Xia, W.; Cha, J.H.; Chan, L.C.; Wu, Y.; Chang, S.S.; Lin, W.C.; Hsu, J.M.; Hsu, Y.H.; et al. Deubiquitination and Stabilization of PD-L1 by CSN5. Cancer Cell 2016, 30, 925–939. [Google Scholar] [CrossRef] [Green Version]
- Wu, Q.; Jiang, L.; Li, S.C.; He, Q.J.; Yang, B.; Cao, J. Small molecule inhibitors targeting the PD-1/PD-L1 signaling pathway. Acta Pharmacol. Sin. 2021, 42, 1–9. [Google Scholar] [CrossRef]
- Liu, C.; Seeram, N.P.; Ma, H. Small molecule inhibitors against PD-1/PD-L1 immune checkpoints and current methodologies for their development: A review. Cancer Cell Int. 2021, 21, 239. [Google Scholar] [CrossRef]
- Tu, X.; Qin, B.; Zhang, Y.; Zhang, C.; Kahila, M.; Nowsheen, S.; Yin, P.; Yuan, J.; Pei, H.; Li, H.; et al. PD-L1 (B7-H1) Competes with the RNA Exosome to Regulate the DNA Damage Response and Can Be Targeted to Sensitize to Radiation or Chemotherapy. Mol. Cell 2019, 74, 1215–1226.e4. [Google Scholar] [CrossRef]
- Ciccolini, J.; Serdjebi, C.; Peters, G.J.; Giovannetti, E. Pharmacokinetics and pharmacogenetics of Gemcitabine as a mainstay in adult and pediatric oncology: An EORTC-PAMM perspective. Cancer Chemother. Pharmacol. 2016, 78, 1–12. [Google Scholar] [CrossRef] [PubMed] [Green Version]
- Agarwala, S.S.; Kirkwood, J.M. Temozolomide, a Novel Alkylating Agent with Activity in the Central Nervous System, May Improve the Treatment of Advanced Metastatic Melanoma. Oncologist 2000, 5, 144–151. [Google Scholar] [CrossRef] [PubMed]
- Kornepati, A.; Murray, C.; Avalos, B.; Rogers, C.; Ramkumar, K.; Gupta, H.; Deng, Y.; Liu, Z.; Padron, A.; Vadlamudi, R.; et al. 900 Depleting non-canonical, cell-intrinsic PD-L1 signals induces synthetic lethality to small molecule DNA damage response inhibitors in an immune independent and dependent manner. J. Immunother. Cancer 2021, 9, A944. [Google Scholar] [CrossRef]
- Yu, J.; Qin, B.; Moyer, A.M.; Nowsheen, S.; Tu, X.; Dong, H.; Boughey, J.C.; Goetz, M.P.; Weinshilboum, R.; Lou, Z.; et al. Regulation of sister chromatid cohesion by nuclear PD-L1. Cell Res. 2020, 30, 590–601. [Google Scholar] [CrossRef] [PubMed]
- Zhang, W.; Jin, J.; Wang, Y.; Fang, L.; Min, L.; Wang, X.; Ding, L.; Weng, L.; Xiao, T.; Zhou, T.; et al. PD-L1 regulates genomic stability via interaction with cohesin-SA1 in the nucleus. Signal Transduct. Target. Ther. 2021, 6, 81. [Google Scholar] [CrossRef] [PubMed]
- Bai, H.; Padrón, Á.; Deng, Y.; Polusan, S.R.; Kornepati, A.; Kari, S.; Kancharla, A.; Garcia, M.; Reyes, R.M.; Ji, N.; et al. Pharmacologic tumor PD-L1 depletion with chlorambucil treats ovarian cancer and melanomas in a tumor PD-L1-dependent manner and renders α PD-L1-resistant tumors into α PD-L1-sensitive. Soc. Immunother. Cancer 2021, 9, A261. [Google Scholar] [CrossRef]
- Obeid, M.; Tesniere, A.; Ghiringhelli, F.; Fimia, G.M.; Apetoh, L.; Perfettini, J.L.; Castedo, M.; Mignot, G.; Panaretakis, T.; Casares, N.; et al. Calreticulin exposure dictates the immunogenicity of cancer cell death. Nat. Med. 2007, 13, 54–61. [Google Scholar] [CrossRef]
- Parsa, A.T.; Waldron, J.S.; Panner, A.; Crane, C.A.; Parney, I.F.; Barry, J.J.; Cachola, K.E.; Murray, J.C.; Tihan, T.; Jensen, M.C.; et al. Loss of tumor suppressor PTEN function increases B7-H1 expression and immunoresistance in glioma. Nat. Med. 2007, 13, 84–88. [Google Scholar] [CrossRef]
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Murray, C.; Galvan, E.; Ontiveros, C.; Deng, Y.; Bai, H.; Padron, A.S.; Hinchee-Rodriguez, K.; Garcia, M.G.; Kornepati, A.; Conejo-Garcia, J.; et al. Pharmacologic Tumor PDL1 Depletion with Cefepime or Ceftazidime Promotes DNA Damage and Sensitivity to DNA-Damaging Agents. Int. J. Mol. Sci. 2022, 23, 5129. https://doi.org/10.3390/ijms23095129
Murray C, Galvan E, Ontiveros C, Deng Y, Bai H, Padron AS, Hinchee-Rodriguez K, Garcia MG, Kornepati A, Conejo-Garcia J, et al. Pharmacologic Tumor PDL1 Depletion with Cefepime or Ceftazidime Promotes DNA Damage and Sensitivity to DNA-Damaging Agents. International Journal of Molecular Sciences. 2022; 23(9):5129. https://doi.org/10.3390/ijms23095129
Chicago/Turabian StyleMurray, Clare, Eva Galvan, Carlos Ontiveros, Yilun Deng, Haiyan Bai, Alvaro Souto Padron, Kathryn Hinchee-Rodriguez, Myrna G. Garcia, Anand Kornepati, Jose Conejo-Garcia, and et al. 2022. "Pharmacologic Tumor PDL1 Depletion with Cefepime or Ceftazidime Promotes DNA Damage and Sensitivity to DNA-Damaging Agents" International Journal of Molecular Sciences 23, no. 9: 5129. https://doi.org/10.3390/ijms23095129