Pyroptosis in Cancer: Tumor Suppressive Role and Therapeutic Implications

Pyroptosis in Cancer

• The role of pyroptosis in cancer is not well understood, but evidence suggests it may play a tumor-suppressive role in melanomas and breast cancers.

SASP CM-mediated Pyroptosis

• Senescent fibroblasts can induce pyroptosis in mammary epithelial cells through SASP CM (senescence-associated secretory phenotype conditioned medium).
• Oncogene expression in normal mammary epithelial cells can prevent SASP CM-mediated cell death, suggesting senescent fibroblasts may eliminate cells that could become cancerous.

Implications of Senolytic Agents

• Senolytic agents, which eliminate senescent cells, may inadvertently remove a mechanism of tumor suppression, highlighting the need to better understand the role of SASP CM-mediated pyroptosis in different cell types and disease contexts.

Cell Culture and Experimental Procedures

• Various cell lines were used, including MCF-10A, BJ human foreskin fibroblasts, MDA-MB-231, MDA-MB-436, HMEC, HuVEC, and KTB-34.
• Cells were cultured in specific media and supplemented with various growth factors and antibiotics.
• Reagents used included z-VAD-fmk, staurosporine, MCC950, Sytox Green, and Hoechst 33342.

Lentiviral Delivery of shRNA

• Lentiviral vectors were used to deliver shRNA constructs against CASP8, CASP1, and GSDMD to generate stable knockdown cell lines.
• Puromycin selection was used to obtain stable populations of puromycin-resistant cells.

Immunoblots and Microscopy

• Immunoblots were performed to confirm knockdowns of CASP1 and GSDMD.
• Immunofluorescence microscopy was used to image cells stained with Hoechst and SYTOX Green to quantify the percentage of SYTOX Green-positive cells.