Project description:Despite significant advances in HER2-targeted therapies, therapeutic resistance in HER2-positive (HER2+) breast cancer remains a significant clinical problem, especially in the metastatic setting. “Drug tolerant persisters” (DTPs), a sub-population of cancer cells that survive via reversible, non-genetic mechanisms, are implicated in resistance to tyrosine kinase inhibitors (TKIs) in several cancer models, but DTPs for HER2-targeted TKIs (e.g., lapatinib, neratinib, tucatinib) have not been characterized extensively. Here, we report that HER2+ER+ and HER2+ER- breast cancer lines give rise to distinct types of “lapatinib-DTPs,” characterized by different transcriptional programs and sensitivity to lapatinib/anti-estradiol combination. Lapatinib-DTPs from HER2+/ER+ cells rewire the PI3K/AKT/mTORC1 pathway via transcriptional induction of SGK3 to enable AKT-independent mTORC1 activation and survival. Lentiviral barcoding experiments, combined with single cell RNA-sequencing, suggest that HER2+ cells stochastically cycle through a cell state (“pre-DTP”) capable of transition to DTPs. Collectively, our results provide insight into DTP ontogeny and therapeutic vulnerabilities.
Project description:Despite significant advances in HER2-targeted therapies, therapeutic resistance in HER2-positive (HER2+) breast cancer remains a significant clinical problem, especially in the metastatic setting. “Drug tolerant persisters” (DTPs), a sub-population of cancer cells that survive via reversible, non-genetic mechanisms, are implicated in resistance to tyrosine kinase inhibitors (TKIs) in several cancer models, but DTPs for HER2-targeted TKIs (e.g., lapatinib, neratinib, tucatinib) have not been characterized extensively. Here, we report that HER2+ER+ and HER2+ER- breast cancer lines give rise to distinct types of “lapatinib-DTPs,” characterized by different transcriptional programs and sensitivity to lapatinib/anti-estradiol combination. Lapatinib-DTPs from HER2+/ER+ cells rewire the PI3K/AKT/mTORC1 pathway via transcriptional induction of SGK3 to enable AKT-independent mTORC1 activation and survival. Lentiviral barcoding experiments, combined with single cell RNA-sequencing, suggest that HER2+ cells stochastically cycle through a cell state (“pre-DTP”) capable of transition to DTPs. Collectively, our results provide insight into DTP ontogeny and therapeutic vulnerabilities.
Project description:Despite advances in HER2-targeted therapeutics, resistance remains a significant clinical problem in HER2-positive (HER2+) breast cancer, especially in the metastatic setting. Drug-tolerant persisters (DTPs), a sub-population of cancer cells that survive via reversible, non-genetic mechanisms, are implicated in resistance to tyrosine kinase inhibitors (TKIs) in several cancer models, but DTPs for HER2-targeted TKIs have not been characterized extensively. We found that upon treatment with the TKI lapatinib, HER2+ breast cancer lines yielded DTPs with luminal-like or mesenchymal-like transcriptional programs and differential sensitivity to lapatinib/anti-estradiol combinations. Lentiviral barcoding and single cell RNA-sequencing indicate that HER2+/ER+ cells cycle stochastically through a pre-DTP state, characterized by a G0-like signature, which uniquely gives rise to DTPs upon lapatinib exposure.
Project description:We compared untreated HCC1419 cells with Lapatinib resistant HCC1419 cells that were either treated with Lapatinib for only 9 days before harvesting (drug tolerant persisters, DTPs) or were growing in the presence of Lapatinib (>70 days) (drug tolerant expanded persisters, DTEPs). We show that the Notch pathway is significantly over-expressed in DTEPs when compared to untreated cells.
Project description:We compared untreated HCC1419 cells with Lapatinib resistant HCC1419 cells that were either treated with Lapatinib for only 9 days before harvesting (drug tolerant persisters, DTPs) or were growing in the presence of Lapatinib (>70 days) (drug tolerant expanded persisters, DTEPs). We show that the Notch pathway is significantly over-expressed in DTEPs when compared to untreated cells. RNA-Seq of HCC1419 cells either untreated, treated with 1?M Lapatinib for 9 days or treated with 1?M Lapatinib for greater than 70 days
Project description:This project investigated the phenotypic characteristics of Metronidazole-tolerant Porphyromonas gingivalis persisters, the relevant modulatory effects of hemin and their underlying survival mechanisms. Proteomic analysis was performed to delineate the protein expression profiles of Metronidazole-tolerant P. gingivalis persister fractions and the controls incubated with different levels of hemin supplementation.