Epithelial to mesenchymal transition induces stem cell like phenotype in renal cell carcinoma cells

Abstract

BackgroundMetastatic dissemination of solid tumors is often initiated by reactivation of an embryonic development program, epithelial-to-mesenchymal-transition (EMT). EMT has been associated with acquiring invasiveness and resistance to conventional therapies. However, the precise role of EMT during renal cell carcinoma is still debatable and is under investigation. In this context, our study is designed to evaluate the role of cyclosporine (CsA) and transforming growth factor-β (TGFβ) administration in inducing EMT-like state in renal carcinoma cells. We also studied the associated phenotypic changes which may lead to tumor metastasis.MethodsThe morphological changes in renal cell carcinoma cells (A498) treated with TGF-β/CsA were observed by microscopy. Atomic force microscope was used to evaluate the changes in elasticity of cells treated with TGF-β/CsA. The expression of mesenchymal and chemoresistance genes were checked by RT-PCR. Assays for migration, invasion, sphere formation ability and expression of cancer stem cell-like phenotypes were done to evaluate the metastatic potential of these cells. Lineage specific differentiations were also done to determine the acquisition of stem-cell like phenotype.ResultsOur results showed that treatment with TGF-β/CsA led to loss of epithelial characteristics and gain of mesenchymal phenotype in vitro. Changes in shape and elastic properties of the cancer cells favoured metastatic progression, increased tumorisphere formation and invasiveness post treatment. We also observed higher expression of chemoresistance and stemness markers in EMT-induced cells. These cells also differentiated to various lineages like osteoblasts, adipocytes, neural and hepatic cells when induced with the respective differentiation media.ConclusionWe concluded that TGF-β/CsA treatment led to acquisition of EMT-like cancer stem cells phenotype that enhanced local invasion and dissemination of renal carcinoma cells. This subpopulation of cells with EMT-like phenotype a can provide a better perception of the metastatic process. This can provide an in vitro system for testing pharmaceuticals for modulating EMT as a viable strategy within the therapeutic armamentarium for RCC patients. The results of our findings also suggest that CsA directly induced EMT like changes in epithelial cell which may be responsible for the potential risk of malignancy in transplant patients.Electronic supplementary materialThe online version of this article (10.1186/s12935-018-0555-6) contains supplementary material, which is available to authorized users.

Histone deacetylase inhibitors dysregulate DNA repair proteins and antagonize metastasis-associated processes

“…The secreted cytokine TGFβ is a tumor suppressor in nontransformed cells through its cell cycle arresting activity. Tumor cells, including those from RCC, are insensitive to this effect of TGFβ and undergo metastasis-promoting EMT and acquire chemotherapy resistance (Hao et al 2019;Singla et al 2018;Tretbar et al 2019). These processes can be abrogated with HDACi in RCC cells.…”

Circular RNA hsa_circ_001895 serves as a sponge of microRNA‐296‐5p to promote clear cell renal cell carcinoma progression by regulating SOX12

“…Both in vivo and in vitro results in the present study showed that hsa_circ_001895 knockdown could increase E‐cadherin and decrease N‐cadherin to inhibit EMT and metastasis of ccRCC. Moreover, EMT also participates in the promotion of ccRCC cancer stemness . Considering that hsa_circ_001895 was associated with EMT of ccRCC, further investigation of hsa_circ_001895 on stemness properties of ccRCC is needed.…”

Identification of an appropriate cell line for the renal cell carcinoma model

“…As non-CSCs can acquire a CSC-like phenotype during EMT [15,16] and EMT-induced cells form spheres [17], a sphere-forming assay was conducted in the RCCs. As the Caki-1 cell line was reported to form more spheres compared to Caki-2 cells [22], the Caki-1 cells were considered a positive control.…”

“…Several RCC markers were found to be speci cally expressed in CSCs, such as CD105, ALDH1, and Oct4, although CSC markers are not unique across tumor types [12,14]. In addition, tumor cells in the non-CSC subpopulation can spontaneously undergo epithelial-mesenchymal transition (EMT) and acquire a CSC-like phenotype and surface marker expression [15][16][17]. High expression of CD44 in RCC also correlated with recurrence and poor prognosis for 5-year overall survival [18].…”