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. 2024 Jan 19;17(1):131.
doi: 10.3390/ph17010131.

Rapamycin as a Potential Alternative Drug for Squamous Cell Gingiva Carcinoma (Ca9-22): A Focus on Cell Cycle, Apoptosis and Autophagy Genetic Profile

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Rapamycin as a Potential Alternative Drug for Squamous Cell Gingiva Carcinoma (Ca9-22): A Focus on Cell Cycle, Apoptosis and Autophagy Genetic Profile

Sofia Papadakos et al. Pharmaceuticals (Basel). .

Abstract

Oral cancer is considered as one of the most common malignancies worldwide. Its conventional treatment primarily involves surgery with or without postoperative adjuvant therapy. The targeting of signaling pathways implicated in tumorigenesis is becoming increasingly prevalent in the development of new anticancer drug candidates. Based on our recently published data, Rapamycin, an inhibitor of the mTOR pathway, exhibits selective antitumor activity in oral cancer by inhibiting cell proliferation and inducing cancer cell apoptosis, autophagy, and cellular stress. In the present study, our focus is on elucidating the genetic determinants of Rapamycin's action and the interaction networks accountable for tumorigenesis suppression. To achieve this, gingival carcinoma cell lines (Ca9-22) were exposed to Rapamycin at IC50 (10 µM) for 24 h. Subsequently, we investigated the genetic profiles related to the cell cycle, apoptosis, and autophagy, as well as gene-gene interactions, using QPCR arrays and the Gene MANIA website. Overall, our results showed that Rapamycin at 10 µM significantly inhibits the growth of Ca9-22 cells after 24 h of treatment by around 50% by suppression of key modulators in the G2/M transition, namely, Survivin and CDK5RAP1. The combination of Rapamycin with Cisplatin potentializes the inhibition of Ca9-22 cell proliferation. A P1/Annexin-V assay was performed to evaluate the effect of Rapamycin on cell apoptosis. The results obtained confirm our previous findings in which Rapamycin at 10 μM induces a strong apoptosis of Ca9-22 cells. The live cells decreased, and the late apoptotic cells increased when the cells were treated by Rapamycin. To identify the genes responsible for cell apoptosis induced by Rapamycin, we performed the RT2 Profiler PCR Arrays for 84 apoptotic genes. The blocked cells were believed to be directed towards cell death, confirmed by the downregulation of apoptosis inhibitors involved in both the extrinsic and intrinsic pathways, including BIRC5, BNIP3, CD40LG, DAPK1, LTA, TNFRSF21 and TP73. The observed effects of Rapamycin on tumor suppression are likely to involve the autophagy process, evidenced by the inhibition of autophagy modulators (TGFβ1, RGS19 and AKT1), autophagosome biogenesis components (AMBRA1, ATG9B and TMEM74) and autophagy byproducts (APP). Identifying gene-gene interaction (GGI) networks provided a comprehensive view of the drug's mechanism and connected the studied tumorigenesis processes to potential functional interactions of various kinds (physical interaction, co-expression, genetic interactions etc.). In conclusion, Rapamycin shows promise as a clinical agent for managing Ca9-22 gingiva carcinoma cells.

Keywords: Rapamycin; apoptosis; autophagy; cell cycle; genetic profile; oral cancer.

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Conflict of interest statement

The authors declare no conflicts of interest.

Figures

Figure 1
Figure 1
Effect of Rapamycin on Ca9-22 cell viability, apoptosis, and autophagy. (A) Effect of Rapamycin on cell growth evaluated by MTT cell proliferation and viability assay. The presented data are expressed as mean ± SEM values of 6 independent experiments. *** p < 0.001 is considered statistically significant. (B) Synergistic effect of Rapamycin and Cisplatin combinations on cell growth revealed by MTT assay (n = 4). (C) Apoptosis assessment conducted using the PI and Annexin markers. Results are expressed as mean ± SEM of 4 independent experiments. (D) Flow cytometry analysis showing the percentage of autophagic cells. Results are expressed as mean ± SEM of 4 independent experiments.
Figure 2
Figure 2
Effect of Rapamycin on Ca9-22 cell cycle arrest markers. (A) Differences in the expression of cell cycle-related genes. QPCR array screening for 84 markers after incubation with 10 µM Rapamycin (n = 3). (BD) Summary of positively and negatively modulated genes. Only fold regulation values above 2 were considered (n = 3). (E) Interaction networks of Rapamycin-regulated genes involved in the cell cycle.
Figure 3
Figure 3
Effect of Rapamycin on Ca9-22 apoptosis markers. (A) Variations in the apoptosis-related gene expression was detected in Ca9-22 cells, both in untreated conditions and those treated with Rapamycin, as determined by QPCR array. A total of 84 markers were included in the screening (n = 3). (B,C) Visualization of log2 fold changes following exposure to Rapamycin relative to untreated cells (n = 3). (D) Table showing the list of genes modulated by Rapamycin as well as the associated fold change (n = 3). (E) Network of gene interactions influenced by Rapamycin, specifically those associated with apoptosis.
Figure 4
Figure 4
Effect of Rapamycin on Ca9-22 autophagy markers. (A) Discrepancies in the expression genes related to autophagy were investigated in Ca9-22 cells under untreated conditions and after treatment with Rapamycin. QPCR array screening for 84 markers was conducted following incubation with 10 µM of Rapamycin (n = 3). (B,C) Visualization of significant changes induced by Rapamycin as compared to untreated cells (n = 3). (D) Display of the genes downregulated by Rapamycin along with the change magnitude (n = 3). (E) Graphical representation of the autophagy gene interaction networks, particularly those linked to the modulated markers.

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References

    1. World Health Organization . WHO Highlights Oral Health Neglect Affecting Nearly Half of the World’s Population. World Health Organization; Geneva, Switzerland: 2022. Global Oral Health Status Report 2022.
    1. Sarode G., Maniyar N., Sarode S.C., Jafer M., Patil S., Awan K.H. Epidemiologic aspects of oral cancer. Dis. Mon. 2020;66:100988. doi: 10.1016/j.disamonth.2020.100988. - DOI - PubMed
    1. National Cancer Institute . Side Effects of Cancer Treatment. National Cancer Institute; Bethesda, MD, USA: 2021.
    1. Parmar A., Macluskey M., Mc Goldrick N., Conway I.D., Glenny A.-M., Clarkson E.J., Worthington H.V., Chan K.K. Interventions for the treatment of oral cavity and oropharyngeal cancer: Chemotherapy. Cochrane Database Syst. Rev. 2021;12:CD006386. - PMC - PubMed
    1. Dasari S., Tchounwou P.B. Cisplatin in cancer therapy: Molecular mechanisms of action. Eur. J. Pharmacol. 2014;740:364–378. doi: 10.1016/j.ejphar.2014.07.025. - DOI - PMC - PubMed

Grants and funding

This research was funded by the Network for Canadian Oral Health and Research (NCOHR). Grand Number: NGH-154223 and by the Researchers Supporting Project (RSPD2024R552) of King Saud University, Riyadh, Saudi Arabia.

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