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Cain, J.

Publications and source records attributed to Cain, J..

3 recordsLinked to original sources

Collagen has a unique SEC24 preference for efficient export from the endoplasmic reticulum

SEC24 is mainly involved in cargo sorting during COPII vesicle assembly. There are four SEC24 paralogs (A to D) in mammals, which are classified into two subgroups (SEC24A/B and SEC24C/D). Pathological mutations in SEC24D cause osteogenesis imperfecta with craniofacial dysplasia in humans. sec24d mutant fish also recapitulate the phenotypes. Consistent with the skeletal phenotypes, the secretion of collagen was severely defective in mutant fish, emphasizing the importance of SEC24D in collagen secretion. However, SEC24D patient-derived fibroblasts show only a mild secretion phenotype, suggesting tissue-specificity in the secretion process. Using Sec24d KO mice and cultured cells, we show that SEC24A and SEC24B also contribute to ER export of procollagen. In contrast, fibronectin 1 requires either SEC24C or SEC24D for ER export. On the basis of our results, we propose that procollagen interacts with multiple SEC24 paralogs for efficient export from the ER, and that this is the basis for tissue-specific phenotypes resulting from SEC24 paralog deficiency.

cell biology

Resistance to platinum chemotherapy in lung adenocarcinoma is driven by a non-genetic, cell-cycle dependent mechanism

We previously used a pulse-based in vitro assay to unveil targetable signalling pathways associated with innate cisplatin resistance in lung adenocarcinoma (Hastings et al., 2020). Here we advanced this model system and identified a non- genetic mechanism of resistance that drives recovery and regrowth in a subset of cells. Using RNAseq and a suite of biosensors to track single cell fates both in vitro and in vivo, we identified that early S phase cells have a greater ability to maintain proliferative capacity, which correlated with reduced DNA damage over multiple generations. In contrast, cells in G1, late S or those treated with PARP/RAD51 inhibitors, maintained higher levels of DNA damage and underwent prolonged S/G2 phase arrest and senescence. Combined with our previous work, these data indicate that there is a non-genetic mechanism of resistance in lung adenocarcinoma that is dependent on the cell cycle stage at the time of cisplatin exposure.

cell biology

Tumor-infiltrating nerves create an electro-physiologically active microenvironment and contribute to treatment resistance

Patients with densely innervated tumors do poorly as compared to those with sparsely innervated disease. Why some tumors heavily recruit nerves while others do not, remains unknown as does the functional contribution of tumor-infiltrating nerves to cancer. Moreover, while patients receive chemotherapeutic treatment, whether these drugs affect nerve recruitment has not been tested. Using a murine model of ovarian cancer, we show that tumor-infiltrating sensory nerves potentiate tumor growth, decrease survival, and contribute to treatment resistance. Furthermore, matched patient samples show significantly increased tumor innervation following chemotherapy. In vitro analysis of tumor-released extracellular vesicles (sEVs) shows they harbor neurite outgrowth activity. These data suggest that chemotherapy may alter sEV cargo, endowing it with robust nerve recruiting capacity.

cancer biology