The DNAJB4 Knockout MES-OV Polyclonal Cells product from Ascent Research is a CRISPR/Cas9-edited polyclonal cell population derived from the MES-OV human ovarian clear cell carcinoma line. This loss-of-function model carries targeted disruption of the DNAJB4 gene, enabling investigation of DNAJB4-dependent processes in a biologically relevant epithelial cancer background. The polyclonal format provides a heterogeneous knockout population suitable for pooled functional screens, stress response profiling, and signaling studies where clonal homogeneity is not required.
MES-OV cells originate from a human ovarian clear cell carcinoma and represent an established model for studying this aggressive epithelial malignancy. These adherent cells retain key molecular features of the ovarian cancer microenvironment, including aberrant activation of oncogenic pathways relevant to proteostasis and apoptosis. The epithelial nature of MES-OV cells makes them particularly appropriate for examining tumor-suppressive functions of chaperones in cancer biology.
DNAJB4 encodes an Hsp40 co-chaperone that directly interacts with HSPA1A/HSPA8 to stimulate their ATPase activity, thereby facilitating ATP-dependent client protein folding, refolding, and degradation. Under conditions of heat shock, oxidative stress, or ER stress, transcription factor HSF1 upregulates DNAJB4 as part of the cellular stress response. DNAJB4 further partners with cofactors BAG3 and STUB1 to direct misfolded proteins toward chaperone-assisted degradation. Downstream consequences of DNAJB4 activity include modulation of BAX/BCL2-mediated apoptosis, AKT1 survival signaling, and MAPK1/3 (ERK1/2) pathway activation. Loss of DNAJB4 disrupts proteostasis, leading to accumulation of damaged proteins and concomitant hyperactivation of AKT and MAPK signaling cascades, as observed in ovarian carcinoma models.
In the context of ovarian clear cell carcinoma, DNAJB4 is believed to function as a tumor suppressor whose loss contributes to oncogenic transformation. The DNAJB4 knockout in MES-OV cells enables researchers to dissect the interplay between protein quality control and malignant signaling. This model is well-suited to interrogate how abrogation of Hsp70 co-chaperone activity influences cellular responses to chemotherapeutic agents, proteotoxic stress, and nutrient deprivation. Moreover, it provides a platform for screening small molecules that target downstream AKT and MAPK pathways or for identifying synthetic lethal interactions with proteostasis defects.
Typical experimental applications include western blotting and RT-qPCR to confirm target disruption, phospho-AKT and phospho-ERK analysis to assess signaling changes, co-immunoprecipitation to map altered protein-protein interactions, and proteasome activity assays to evaluate degradation capacity. Researchers can employ apoptosis and cell viability assays to study drug sensitivity, and migration assays to gauge metastatic potential. Heat shock response assays further allow monitoring of stress adaptation deficits. This knockout cell product is a valuable tool for advancing fundamental understanding of chaperone networks in ovarian cancer and for preclinical evaluation of therapeutic strategies. For additional technical information or to discuss customized applications, please contact Ascent Research.
