RESUMO
Intratumoral heterogeneity, including in clear cell renal cell carcinoma, is a potential cause of drug resistance and metastatic cancer progression. We specified the heterogeneous population marked by endoglin (also known as CD105) in a preclinical model of clear cell renal cell carcinoma progression. Highly malignant derivatives of human clear cell renal cell carcinoma OS-RC-2 cells were established as OS5Ks by serial orthotopic inoculation in our previous study. Expression of both ENG (encoding endoglin) mRNA and protein were heterogeneously upregulated in OS5Ks, and the endoglin-positive (ENG+ ) population exhibited growth dependency on endoglin in anchorage-independent cultures. Despite the function of endoglin as a type III receptor, transforming growth factor ß and bone morphogenetic protein-9 signaling were unlikely to contribute to the proliferative phenotype. Although endoglin has been proposed as a marker for renal cancer-initiating cells, the OS5K-3 ENG+ population did not enrich other reported cancer-initiating cell markers or differentiate into the ENG- population. Mouse tumor inoculation models revealed that the tumor-forming capabilities of OS5K-3 ENG+ and ENG- cells in vivo were highly dependent on the microenvironment, with the renal microenvironment most preferable to ENG+ cells. In conclusion, the renal microenvironment, rather than the hypothesized ENG+ cell-centered hierarchy, maintains cellular heterogeneity in clear cell renal cell carcinoma. Therefore, the effect of the microenvironment should be considered when evaluating the proliferative capability of renal cancer cells in the experimental settings.
Assuntos
Carcinoma de Células Renais/patologia , Endoglina/genética , Endoglina/metabolismo , Neoplasias Renais/patologia , Regulação para Cima , Animais , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Heterogeneidade Genética , Humanos , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Masculino , Camundongos , Transplante de Neoplasias , Células-Tronco Neoplásicas/metabolismo , Microambiente TumoralRESUMO
Advanced clear cell renal cell carcinoma (ccRCC) frequently causes systemic inflammation. Recent studies have shown that cancer cells reshape the immune landscape by secreting cytokines or chemokines. This phenotype, called cancer-cell-intrinsic inflammation, triggers a metastatic cascade. Here, we identified the functional role and regulatory mechanism of inflammation driven by advanced ccRCC cells. The inflammatory nature of advanced ccRCC was recapitulated in a preclinical model of ccRCC. Amplification of cancer-cell-intrinsic inflammation during ccRCC progression triggered neutrophil-dependent lung metastasis. Massive expression of inflammation-related genes was transcriptionally activated by epigenetic remodelling through mechanisms such as DNA demethylation and super-enhancer formation. A bromodomain and extra-terminal motif inhibitor synchronously suppressed C-X-C-type chemokines in ccRCC cells and decreased neutrophil-dependent lung metastasis. Overall, our findings provide insight into the nature of inflammatory ccRCC, which triggers metastatic cascades, and suggest a potential therapeutic strategy.
