The cell stress response is an essential system present in every cell for responding and adapting to extracellular environmental stimulations. A major program for stress response is the heat shock factor (HSF)–heat shock protein (HSP) system that maintains proteostasis in cells and promotes cancer progression. However, less is known about how the cell stress response is regulated by alternative transcription factors. Here, we show that the SCAN domain-containing transcription factors (SCAN-TFs) are involved in repressing the stress response in cancer. SCAND1 and SCAND2 are SCAN-TFs that can hetero-oligomerize with SCAN-zinc finger transcription factors, such as MZF1(ZSCAN6), for accessing DNA and transcriptionally co-repressing target genes. We found that heat stress induced the expression of both SCAND1 and MZF1(ZSCAN6) bound to HSP90 gene promoter regions in prostate cancer cells. SCAND1 and MZF1 blocked the heat shock responsiveness of HSP90 in prostate cancer cells. Gene expression of SCAND2, SCAND1 and MZF1 was negatively correlated with HSP90 expression in patients-derived prostate adenocarcinoma. MZF1 and SCAND2 were more highly expressed in paired normal tissues than in tumor tissues in several cancer types. High expression of SCAND2, SCAND1 and MZF1 correlated with enhanced prognoses of pancreatic cancer and head and neck cancers. Additionally, high expression of SCAND2 was correlated with better prognoses of lung adenocarcinoma and sarcoma. In contrast, high expression of HSP90AA1 correlated with poorer prognoses in several cancer types. These data suggest that the stress-inducible SCAN-TFs can function as a feedback system, suppressing excessive stress response and inhibiting cancers.

Extracellular vesicles (EV), including exosomes and microvesicles, are released from various cells and alter recipient cell phenotypes and fates by their biomolecules. Here we review current knowledge about tumor EVs and how they prompt malignant cell communication with tumor-associated cells, such as cancer-associated fibroblasts, tumor endothelial cells, and immune cells. We delineate the major pathways and molecular players that influence each step of cancer initiation, progression, and resistance. Of note, cancer exosomes involve immunosuppression by tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells. Moreover, tumor exosomes can induce the apoptosis of killer T cells and immune checkpoint of dendritic cells and attenuate natural killer cells. An in-depth understanding of EV biology is essential to ensure the clinical development of exosome/EV-based therapeutic products, which will be of benefit to exosome manipulation in cancer management.