Volume 25, Issue 118, December 2021

Flow cytometric assessment of nivolumab and/or epigallocatechin-3-gallate on cancer stem cells of DMBA induced hamster buccal pouch carcinoma

Mohamed Alaa Al-Dosoki^1♦, Ahmed Abd-Alshakor Abd-Alhafez², Asmaa Mohamed Zahran Omar³, Mohamed Gomaa Attia Zouair⁴

¹Assistant Lecturer, Oral and Dental Pathology Department, Faculty of Dental Medicine (Boys- Cairo), Al-Azhar University, Egypt
²Lecturer, Oral and Dental Pathology Department, Faculty of Dental Medicine (Boys- Cairo), Al-Azhar University, Egypt
³Assistant Professor, Department of Clinical Pathology, South Egypt Cancer Institute, Assiut University, Egypt
⁴Professor, Oral and Dental Pathology Department, Faculty of Dental Medicine (Boys-Cairo), Al-Azhar University, Egypt

^♦Corresponding author
Assistant Lecturer, Oral and Dental Pathology Department, Faculty of Dental Medicine (Boys- Cairo), Al-Azhar University, Egypt

ABSTRACT

The aim of the present study was to investigate the effect of nivolumab and/or epigallocatechin-3-gallate (EGCG) on cancer stem cell(s) (CSC(s)) of DMBA induced hamster buccal pouch squamous cell carcinoma (HBPSCC). Material and methods: fifty Syrian male hamsters were divided into five group(s) (G(s)), 10 each. GI: negative control, left untreated. The right pouches of those in GII, GIII, GIV and GV were painted with DMBA (3times /a week/ 14 weeks). GII: positive control, not received other treatment. GIII was injected with intraperitoneally (IP) with nivolumab only, while GIV with IP with EGCG only, whereas GV with IP (combination of nivolumab and EGCG). After termination of the experiment, gross observation was recorded, the animals were euthanized, and all pouches were surgically excised and bisected. The first piece was prepared for H & E stain and immunohistochemical (IHC) staining utilizing CD68 and CD3. The other piece was used for flow cytometric (FCM) assessment for identification and sorting of CSCs using CD44 & CD24 antibodies. Then, apoptosis assay of the sorted CSCs was employed. Results: gross observations, H & E stain, IHC and FCM results revealed some variability throughout the treated Gs (GIII-GV) compared to those observed in GII. CSCs sorting, CD44+, CD24-& CD44+, CD24+ revealed high significant difference between GII and Gs: GIII- GV (p value < 0.001). The sorted CSCs apoptosis recorded highly significant difference between GII and other Gs {(GIII- GV) (p value < 0.001)}. Conclusion: combination of EGCG-nivolumab significantly inhibits tumor progression and induces apoptosis in CSCs of HBPSCC.

Keywords: HBP carcinoma, EGCG, nivolumab, CSC.

Medical Science, 2021, 25(118), 3206-3221

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