Similar Datasets
Project description:Over-activation of oncogenes by aberrant expression of epigenetic modulators, overcoming cell cycle checkpoints and bestowing infinite multiplication potency acts as the mainstay of malignancy. We identified one such non-receptor tyrosine kinase ACK1 as an epigenetic regulator of cell cycle genes governing the G2/M transition of breast cancer cells. ACK1 was found to be over-activated (pY264-ACK1) in most of the breast cancer sub-types, independent of their hormone receptor status, as assessed by the Tissue-microarray analysis of nearly 400 breast cancer patient samples. ACK1 primed the epigenetic landscape surrounding the genes CCNB1, CCNB2 and CDC20 by depositing Y88-H4 histone activation marks, in turn initiating their efficient transcription. Pharmacological inhibition of ACK1 using small molecular inhibitor (R)-9b not only reversed this transcriptional potential but also sensitized the cells to a G2/M arrest, culminating in breast cancer cell death and tumor regression in in vivo xenograft models of breast cancer. Further, ACK1 was also found to modulate expression of the gene CXCR4, circumventing breast cancer metastasis on ACK1 ablation. In addition, ACK1 inhibition was also found to counteract the resistance of RB1 deficient breast cancer cells to the CDK4/6 inhibitor palbociclib, overcoming road blocks to conventional therapeutics. Overall, our data warrants the identification of ACK1 as an epigenetic controller of genes essential for the successful establishment and progression of breast cancer and signifies development of therapeutics against ACK1 to combat intrinsic and acquired breast cancer resistance.
2023-05-23 | GSE203231 | GEO
Project description:Over-activation of oncogenes by aberrant expression of epigenetic modulators, overcoming cell cycle checkpoints and bestowing infinite multiplication potency acts as the mainstay of malignancy. We identified one such non-receptor tyrosine kinase ACK1 as an epigenetic regulator of cell cycle genes governing the G2/M transition of breast cancer cells. ACK1 was found to be over-activated (pY264-ACK1) in most of the breast cancer sub-types, independent of their hormone receptor status, as assessed by the Tissue-microarray analysis of nearly 400 breast cancer patient samples. ACK1 primed the epigenetic landscape surrounding the genes CCNB1, CCNB2 and CDC20 by depositing Y88-H4 histone activation marks, in turn initiating their efficient transcription. Pharmacological inhibition of ACK1 using small molecular inhibitor (R)-9b not only reversed this transcriptional potential but also sensitized the cells to a G2/M arrest, culminating in breast cancer cell death and tumor regression in in vivo xenograft models of breast cancer. Further, ACK1 was also found to modulate expression of the gene CXCR4, circumventing breast cancer metastasis on ACK1 ablation. In addition, ACK1 inhibition was also found to counteract the resistance of RB1 deficient breast cancer cells to the CDK4/6 inhibitor palbociclib, overcoming road blocks to conventional therapeutics. Overall, our data warrants the identification of ACK1 as an epigenetic controller of genes essential for the successful establishment and progression of breast cancer and signifies development of therapeutics against ACK1 to combat intrinsic and acquired breast cancer resistance.
2023-05-23 | GSE203230 | GEO
Project description:ACK1/TNK2 Epigenetically Regulates Cell Cycle Program to Promote Breast Cancer Resistance to CDK4/6 inhibitor
| PRJNA839095 | ENA
Project description:ACK1/TNK2 Epigenetically Regulates Cell Cycle Program to Promote Breast Cancer Resistance to CDK4/6 inhibitor (ChIP-Seq)
| PRJNA839098 | ENA
Project description:ACK1/TNK2 Epigenetically Regulates Cell Cycle Program to Promote Breast Cancer Resistance to CDK4/6 inhibitor (RNA-Seq)
| PRJNA839097 | ENA
Project description:Cyclin-dependent kinases 4 and 6 (CDK4/6) play a pivotal role in cell cycle and cancer development. Targeting CDK4/6 has demonstrated promising effects against breast cancer. However, resistance to CDK4/6 inhibitors (CDK4/6i), such as palbociclib, remains a substantial challenge in clinical settings. Using high-throughput combinatorial drug screening and genomic sequencing, we find that the microphthalmia-associated transcription factor (MITF) is activated via O-GlcNAcylation by O-GlcNAc transferase (OGT) in palbociclib-resistant breast cancer cells and tumors. Mechanistically, O-GlcNAcylation of MITF at Serine 49 enhances its interaction with importin α/β, thus promoting its translocation to nuclei, where it suppresses palbociclib-induced senescence. Inhibition of MITF or its O-GlcNAcylation re-sensitizes resistant cells to palbociclib. Moreover, clinical studies confirm the activation of MITF in tumors from patients who are palbociclib-resistant or undergoing palbociclib treatment. Collectively, our studies shed light on the mechanism regulating palbociclib resistance and present clinical evidence for developing therapeutic approaches to treat CDK4/6i-resistant breast cancer patients.
| S-EPMC11222436 | biostudies-literature
Project description:Intrinsic resistance to CDK4/6 inhibitors hinders their clinical utility in cancer treatment. Furthermore, the predictive markers of CDK4/6 inhibitors in gastric cancer (GC) remain incompletely described. Here, we found that PAX6 expression was negatively correlated with the response to palbociclib in vitro and in vivo in GC. We observed that the PAX6 expression level was negatively correlated with the overall survival of GC patients and further showed that PAX6 can promote GC cell proliferation and the cell cycle. The cell cycle is regulated by the interaction of cyclins with their partner serine/threonine cyclin-dependent kinases (CDKs), and the G1/S-phase transition is the main target of CDK4/6 inhibitors. Therefore, we tested whether PAX6 expression was correlated with the GC response to palbociclib. We found that PAX6 hypermethylates the promoter of LATS2 and inactivates the Hippo pathway, which upregulates cyclin D1 (CCND1) expression. This results in a suppressed response to palbociclib in GC. Furthermore, we found that the induction of the Hippo signaling pathway or treatment with a DNA methylation inhibitor could overcome PAX6-induced palbociclib resistance in GC. These findings uncover a tumor promoter function of PAX6 in GC and establish overexpressed PAX6 as a mechanism of resistance to palbociclib.
| S-EPMC8382979 | biostudies-literature
Project description:Significant endocrine therapy-resistant tumor proliferation is present in ?20% of estrogen receptor-positive (ER+) primary breast cancers and is associated with disease recurrence and death. Here, we uncover a link between intrinsic endocrine therapy resistance and dysregulation of the MutL mismatch repair (MMR) complex (MLH1/3, PMS1/2), and demonstrate a direct role for MutL complex loss in resistance to all classes of endocrine therapy. We find that MutL deficiency in ER+ breast cancer abrogates CHK2-mediated inhibition of CDK4, a prerequisite for endocrine therapy responsiveness. Consequently, CDK4/6 inhibitors (CDK4/6i) remain effective in MutL-defective ER+ breast cancer cells. These observations are supported by data from a clinical trial where a CDK4/6i was found to strongly inhibit aromatase inhibitor-resistant proliferation of MutL-defective tumors. These data suggest that diagnostic markers of MutL deficiency could be used to direct adjuvant CDK4/6i to a population of patients with breast cancer who exhibit marked resistance to the current standard of care.Significance: MutL deficiency in a subset of ER+ primary tumors explains why CDK4/6 inhibition is effective against some de novo endocrine therapy-resistant tumors. Therefore, markers of MutL dysregulation could guide CDK4/6 inhibitor use in the adjuvant setting, where the risk benefit ratio for untargeted therapeutic intervention is narrow. Cancer Discov; 7(10); 1168-83. ©2017 AACR.This article is highlighted in the In This Issue feature, p. 1047.
| S-EPMC5733075 | biostudies-literature
Project description:Breast cancer (BC) is the most common cause of cancer-related death in women worldwide. Therapies targeting molecular pathways altered in BC had significantly enhanced treatment options for BC over the last decades, which ultimately improved the lives of millions of women worldwide. Among various molecular pathways accruing substantial interest for the development of targeted therapies are cyclin-dependent kinases (CDKs)-in particular, the two closely related members CDK4 and CDK6. CDK4/6 inhibitors indirectly trigger the dephosphorylation of retinoblastoma tumor suppressor protein by blocking CDK4/6, thereby blocking the cell cycle transition from the G1 to S phase. Although the CDK4/6 inhibitors abemaciclib, palbociclib, and ribociclib gained FDA approval for the treatment of hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative BC as they significantly improved progression-free survival (PFS) in randomized clinical trials, regrettably, some patients showed resistance to these therapies. Though multiple molecular pathways could be mechanistically responsible for CDK4/6 inhibitor therapy resistance, one of the most predominant ones seems to be the fibroblast growth factor receptor (FGFR) pathway. FGFRs are involved in many aspects of cancer formation, such as cell proliferation, differentiation, and growth. Importantly, FGFRs are frequently mutated in BC, and their overexpression and/or hyperactivation correlates with CDK4/6 inhibitor resistance and shortened PFS in BC. Intriguingly, the inhibition of aberrant FGFR activity is capable of reversing the resistance to CDK4/6 inhibitors. This review summarizes the molecular background of FGFR signaling and discusses the role of aberrant FGFR signaling during cancer development in general and during the development of CDK4/6 inhibitor resistance in BC in particular, together with other possible mechanisms for resistance to CDK4/6 inhibitors. Subsequently, future directions on novel therapeutic strategies targeting FGFR signaling to overcome such resistance during BC treatment will be further debated.
| S-EPMC7912842 | biostudies-literature
Project description:CDK4/6 inhibitors have become game-changers in the treatment of estrogen receptor-positive (ER+) breast cancer, and in combination with endocrine therapy are the standard of care first-line treatment for ER+/HER2-negative advanced breast cancer. Although CDK4/6 inhibitors prolong survival for these patients, resistance is inevitable and there is currently no clear standard next-line treatment. There is an urgent unmet need to dissect the mechanisms which drive intrinsic and acquired resistance to CDK4/6 inhibitors and endocrine therapy to guide the subsequent therapeutic decisions. We will review the insights gained from preclinical studies and clinical cohorts into the diverse mechanisms of CDK4/6 inhibitor action and resistance, and highlight potential therapeutic strategies in the context of CDK4/6 inhibitor resistance.
| S-EPMC10073728 | biostudies-literature