The DNAJB4 Knockout 786-O Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the 786-O human clear cell renal cell carcinoma line. This pool contains cells with targeted disruption of the DNAJB4 gene, encoding the Hsp40 co-chaperone. Ablating DNAJB4 expression permits investigation of its tumor-suppressive functions and chaperone-dependent proteostasis in a VHL-deficient renal cancer background. The heterogeneous editing outcomes inherent to a polyclonal population provide a robust loss-of-function model without clonal selection bias.
The 786-O cell line, established from a primary renal adenocarcinoma, is VHL-deficient, leading to stabilization of hypoxia-inducible factors (HIFs) and pseudohypoxic transcriptional programs that drive angiogenesis, metabolic reprogramming, and proliferation. This well-characterized ccRCC model enables dissection of the interplay between DNAJB4-mediated proteostasis and hypoxia-driven oncogenic signaling in a clinically relevant context.
DNAJB4 is an Hsp40 co-chaperone that binds Hsp70 (HSPA1A) and stimulates its ATPase activity, facilitating protein folding and preventing aggregation. It modulates quality control of clients like p53, supporting p53 stability and transcriptional activity to promote pro-apoptotic signals. Upstream regulators include heat shock factor 1 (HSF1), heat shock, and promoter methylation. Downstream, p53 targets and pro-apoptotic factors mediate tumor suppression. Interacting factors such as BAG1 and HSPH1 fine-tune the Hsp70 cycle, linking DNAJB4 to proteostasis and p53 signaling.
In 786-O cells, DNAJB4 knockout disrupts chaperone-mediated proteostasis, potentially causing accumulation of misfolded clients and attenuated p53 tumor suppression. With VHL loss already compromising protein quality control and elevating oxidative stress, DNAJB4 removal may exacerbate proteotoxic stress while unlocking oncogenic pathways. This polyclonal model thus enables exploration of co-chaperone dysfunction in ccRCC progression and testing of synthetic lethality with chaperone inhibitors or proteotoxic agents.
Applications include western blotting for Hsp70 and p53, co-immunoprecipitation of Hsp70-client interactions, apoptosis and migration/invasion assays, and RNA-seq transcriptomics to probe proteostatic and oncogenic changes. The model can be used to screen Hsp70 modulators or to target protein folding pathways in ccRCC. For inquiries or custom applications, contact Ascent Research.
