Project description:Part1: Epigenetic Drug Screening Defines a PRMT5 Inhibitor Sensitive Pancreatic Cancer Subtype; Part2: Indirect targeting of MYC sensitizes pancreatic cancer cellsto mechanistic target of rapamycin (mTOR) inhibition
Project description:Targeting the PI3K-AKT-mTOR pathway is a promising therapeutic strategy for breast cancer treatment. However, low response rates and the development of acquired resistance to PI3K-AKT-mTOR inhibitors remain major challenges for successful patient treatment. Here, we show that MYC activation is a central and clinically relevant mechanism of resistance to mTOR inhibitors (mTORi) in breast cancer. Multi-omic profiling of mouse invasive lobular carcinoma (ILC) tumors revealed recurrent focal Myc amplification in tumors that acquire resistance to the mTORi AZD8055. The gained MYC activity was significantly associated with biological processes linked to mTORi response. Specifically, MYC counteracted the translation inhibitory effect induced by mTORi by promoting the translation of ribosomal proteins. In vitro and in vivo induction of MYC conferred resistance to AZD8055 as well as the clinically approved mTORi everolimus, both in mouse models of ILC and human breast cancer models. Conversely, AZD8055-resistant ILC cells depended on MYC, as demonstrated by synergistic growth inhibition using mTORi and MYCi combination treatment. Notably, MYC status was significantly associated with poor response to everolimus therapy in metastatic breast cancer patients. Thus, MYC is a clinically relevant determinant of mTORi resistance that may guide the selection of breast cancer patients for mTOR targeted therapies.
Project description:The oncogene MYC drives many cancers and is an outstanding therapeutic target. MYC is an intrinsically disordered protein, and therefore, targeting MYC remains a challenge. Here, we developed a proteolysis targeting chimera (PROTAC) degrading MYC: MDEG-541. The inhibitor is based on the MYC-MAX dimerization inhibitor 10058-F4 and Thalidomide. Mode of action depends on the proteasome and cereblon. MDEG-541 shows single digit mM activity in most sensitive colon and pancreatic cancer cell lines as well as gastrointestinal tumor organoids.
Project description:Although 3-Phosphoinositide-dependent protein kinase-1 (PDK1) has been predominately linked to PI3K-AKT pathway, it may also evoke additional signaling outputs to promote tumorigenesis. Here we report that PDK1 directly induces phosphorylation of Polo-like kinase 1 (PLK1), which in turn induces Myc phosphorylation and protein accumulation. We show that PDK1-PLK1-Myc signaling is critical for cancer cell growth and survival and small molecule inhibition of PDK1/PLK1 provides an effective approach for therapeutic targeting Myc-dependency. Intriguingly, PDK1-PLK1-Myc signaling induces an embryonic stem cell-like gene signature associated with aggressive tumor behaviors and is a robust signaling axis driving cancer stem cell (CSC) self renewal. Finally, we show that PLK1 inhibitor synergizes with mTOR inhibitor to induce synergistic anti-tumor effect in colorectal cancer by antagonizing a compensatory Myc induction. These findings identify a novel pathway in human cancer and CSC activation and provide a therapeutic strategy for targeting Myc-associated tumorigenesis and therapeutic resistance. Gene expression profiling of Human Embryonic Kidney Cells (HEK-TERV) under different conditions: PMN, PDK1, MYC and E545K
Project description:This phase I/II trial studies the side effects and best dose of lenalidomide when given together with combination chemotherapy and to see how well they work in treating patients with v-myc myelocytomatosis viral oncogene homolog (avian) (MYC)-associated B-cell lymphomas. Lenalidomide may stop the growth of B-cell lymphomas by blocking the growth of new blood vessels necessary for cancer growth and by blocking some of the enzymes needed for cell growth. Biological therapies, such as lenalidomide, use substances made from living organisms that may stimulate or suppress the immune system in different ways and stop cancer cells from growing. Drugs used in chemotherapy, such as etoposide, prednisone, vincristine sulfate, doxorubicin hydrochloride, cyclophosphamide, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Monoclonal antibodies, such as rituximab, may block cancer growth in different ways by targeting certain cells. Giving lenalidomide together with combination chemotherapy may be an effective treatment in patients with B-cell lymphoma.
Project description:We used RNA-seq to examine the effect of Myc activation on U2OS cells transcriptome. We also examined these effects in the presence of Torin-1, an inhibitor of mTOR We measure gene expression profiles in U2OS cells containing an inducible Myc expression vector that were induced or mock-treated in duplicates for 36 hours. In addition, we repeated the experiments in the presence of Torin-1, an inhibitor of mTOR.
Project description:This SuperSeries is composed of the following subset Series: GSE25170: MYC drives resistance to PI3K/mTOR targeted inhibition (Sty SNP array) GSE25172: MYC drives resistance to PI3K/mTOR targeted inhibition (gene expression) Refer to individual Series
Project description:We used Ribo-seq to examine the effect of Myc activation on protein translation in U2OS cells and correalted these changes with alterations in RNA level measured by RNA-seq on tye same conditions. We also examined these effects in the presence of Torin-1, an inhibitor of mTOR We measure ribosome occupancy profiles in U2OS cells containing an inducible Myc expression vector that were induced or mock-treated in duplicates for 36 hours. In addition, we repeated the experiments in the presence of Torin-1, an inhibitor of mTOR.
Project description:Gastric cancer (GC) is one of the most common malignant cancers in the world. c-Myc, a well-known oncogene, is commonly amplified in many cancers, including gastric cancer. However, it is still not completely understood how c-Myc functions in GC. Here, we generated a stomach-specific c-Myc knock-in mouse model to investigate its role in GC. We found that overexpression of c-Myc in Atp4b+ gastric parietal cells could induce intestinal-type gastric cancer in mice. Mechanistically, c-Myc promoted tumorigenesis via the AKT/mTOR pathway. Furthermore, AKT inhibitor (MK-2206) or mTOR inhibitor (Rapamycin) inhibited the proliferation of c-Myc overexpressing gastric cancer cell lines. Thus, our findings highlight that gastric cancer can be induced by c-Myc overexpression through activation of the AKT/mTOR pathway.