Correlation of expression Cancer stem cell markers in oral squamous cell carcinoma in hamster through radiotherapy

Abstract

Background: Oral squamous cell carcinoma is the most common tumor characterized by recurrence and invasion and there are  many evidences have shown that recurrence and metastasis are associated with subgroup of cancer stem cells (CSCs) after treatment, this cells group responible of migration and invasion. CSCs-markers are various, some of them in OSCC are CD44, ALDH1A1

Aim of study: Investigate the expression of CD44, ALDH1A1 in oral squamous cell carcinoma (OSCC) after induced it in hamsters, then apply radiotherapy and compare them before and after treatment to verify the influence of these markers through radiotherapy and radiosensitivity

Materials & methods: It consisted 36 of hamesters (18 samples of OSCC which induced in the right cheek sinus of hamsters and 18 samples of OSCC which induced in the right cheek sinus of hamsters  and were exposed to radiation therapy), Biopsies were taken and fixed with formalin, paraffin waxed in conventional H&E and immunostained with monoclonal anti- Aldehyde dehydrogenase 1 A1 and anti-cluster of differentiation 44.

Results: These markers showed positive expression in all samples and ranged from medium to high in oral squamous cell carcinoma before and after radiotherapy, there is a resistance in some of  islands and neoplastic cells even after receiving 30 Gy

  After immunostaining, we found a decrease in the number of samples that took high expression after treatment, but with non-statistically significant differences, on the other hand, we had a correlation between CD44 and  ALDH1A1, moderately before treatment and high after treatment

.Conclusion: resistance of tumor cells to radiotherapy may be due to the presence of this positive expression of CSCs markers, as they didn't give a high radiosensitivity and prevented DNA damage during treatment. Thus, it is important to find a supportive treatment using targeting these markers with radiotherapy to reach a better treatment.

This correlation between two markers may help to find a common pathway to eliminate radioresistant cells, but immunostaining is not sufficient to clearly identify CSCs.