Research Projects

In India, cervical cancer (CC) is a major public health concern as it is contributing closely to 123,907 new cases and 77,348 deaths annually. Hence, it is important to control both incidence and mortality due to CC. Stem cells are small subpopulation of cells with self-renewal and multi-differentiation capacity that may play a central role in cervical carcinogenesis via promoting metastasis, recurrence, and therapy resistance. The interaction of cancer stem cells with immune cells and tumor microenvironment is proposed as critical factors that may drive CC progression. Thus, the cancer stem cell population can be considered as a unique target for improved therapeutic outcomes, given its capacity to drive carcinogenesis. miRNAs are small non-coding RNA important for fine tuning the expression of protein coding genes. miRNAs can control stem cell fate by targeting pluripotency factors and genes related to differentiation pathways. Yet, the exact role of miRNAs in stem cell reprogramming, and their contribution to CC is elusive. The miR-127/miR-136 cluster consists of 11 miRNAs driven by single promoters. In cervical cancer, miR-127/miR-136 cluster members are downregulated and inhibits growth, proliferation, migration, and invasion via targeting genes such as EGFR, FN1, FOXD1, TFCP2, PAK2, and TCF12. To the best of our knowledge, previous clinical and functional studies in CC had focused on investigating the role of individual miRNA members than the entire miR-127/miR-136 cluster. Hence, the role of the entire miR-127/miR-136 cluster in CC remains to be explored. Our long-term aim is to understand how the downregulation of the entire miR-127/miR-136 cluster determines stem cell fate, contributes to CC and to develop RNAi based therapeutics against cervical cancer. Our preliminary data shows that miR-127/miR-136 cluster is downregulated in squamous cell carcinoma of cervix than normal samples by small RNA seq analysis. The in-silico analysis of TCGA cervical cancer datasets also indicated downregulation of members of this cluster in cancer samples. Overexpression of the entire miR-127/miR-136 cluster using pCDH-CMV-MCS-EF1-Puro vector inhibited growth and proliferation of HeLa and SiHa cells. Target prediction analysis suggested that stem cell transcription factors such as KLF4, cMYC, and SOX2 are the targets of hsa-miR-493-5p, hsa-miR-665, and hsa-miR-493-5p. Interestingly, we found a significant inverse correlation between the expression of these miRNAs with that of their target genes in CC clinical samples. Thus, we hypothesize that the downregulation of entire miR-127/miR136 cluster may be a critical step towards promoting stemness and activation of this cluster may be an attractive approach to reduce stemness in CC. Therefore, we wish to understand the biological functions, molecular mechanisms and signaling pathways regulated by entire miR-127/miR-136 cluster in stem cell fate determination using cervical cancer stem cells.