Cancer research最新文献

Cancer cells use multiple mechanisms to evade the effects of glutamine metabolism inhibitors. The pathways that govern responses to alterations in glutamine availability within the tumor may represent therapeutic targets for combinatorial strategies with these inhibitors. Here, we showed that targeting glutamine utilization stimulated Yes-associated protein (YAP) signaling in cancer cells by reducing cyclic adenosine monophosphate/protein kinase A (PKA)-dependent phosphorylation of large tumor suppressor (LATS). Elevated YAP activation induced extracellular matrix (ECM) deposition by increasing the secretion of connective tissue growth factor that promoted the production of fibronectin and collagen by surrounding fibroblasts. Consequently, inhibiting YAP synergized with inhibition of glutamine utilization to effectively suppress tumor growth in vivo, along with a concurrent decrease in ECM deposition. Blocking ECM remodeling also augmented the tumor suppressive effects of the glutamine utilization inhibitor. Collectively, these data reveal mechanisms by which targeting glutamine utilization increases ECM accumulation and identify potential strategies to reduce ECM levels and increase the efficacy of glutamine metabolism inhibitors. Significance: Blocking glutamine utilization activates YAP to promote ECM deposition by fibroblasts, highlighting the potential of YAP inhibitors and antifibrotic strategies as promising approaches for effective combination metabolic therapies in cancer.

Castration-resistant prostate cancer (CRPC) is incurable and fatal, making prostate cancer the second-leading cancer-related cause of death for American men. CRPC results from therapeutic resistance to standard-of-care androgen deprivation (AD) treatments, through incompletely understood molecular mechanisms, and lacks durable therapeutic options. Here, we identified enhanced soluble guanylyl cyclase (sGC) signaling as a mechanism that restrains CRPC initiation and growth. Patients with aggressive, fatal CRPC exhibited significantly lower serum levels of the sGC catalytic product cyclic GMP (cGMP) compared to their castration-sensitive stage. In emergent castration-resistant cells isolated from castration-sensitive prostate cancer (CSPC) populations, the obligate sGC heterodimer was repressed via methylation of its beta subunit. Genetically abrogating sGC complex formation in CSPC cells promoted evasion of AD-induced senescence and concomitant castration-resistant tumor growth. In established castration-resistant cells, the sGC complex was present but in a reversibly oxidized and inactive state. Subjecting CRPC cells to AD regenerated the functional complex, and co-treatment with riociguat, an FDA-approved sGC agonist, evoked redox stress-induced apoptosis. Riociguat decreased castration-resistant tumor growth and increased apoptotic markers, with elevated cGMP levels correlating significantly with lower tumor burden. Riociguat treatment reorganized tumor vasculature and eliminated hypoxic tumor niches, decreasing CD44+ tumor progenitor cells and increasing the radiosensitivity of castration-resistant tumors. Thus, this study showed that enhancing sGC activity can inhibit CRPC emergence and progression through tumor cell-intrinsic and extrinsic effects. Riociguat can be repurposed to overcome CRPC, with noninvasive monitoring of cGMP levels as a marker for on-target efficacy.

Neuroendocrine cells have been implicated in therapeutic resistance and worse overall survival in many cancer types. Mucinous colorectal cancer (mCRC) is uniquely enriched for enteroendocrine cells (EECs), the neuroendocrine cell of the normal colon epithelium, as compared to non-mCRC. Therefore, targeting EEC differentiation may have clinical value in mCRC. Here, single cell multi-omics uncovered epigenetic alterations that accompany EEC differentiation, identified STAT3 as a regulator of EEC specification, and discovered a rare cancer-specific cell type with enteric neuron-like characteristics. Furthermore, LSD1 and CoREST2 mediated STAT3 demethylation and enhanced STAT3 chromatin binding. Knockdown of CoREST2 in an orthotopic xenograft mouse model resulted in decreased primary tumor growth and lung metastases. Collectively, these results provide rationale for developing LSD1 inhibitors that target the interaction between LSD1 and STAT3 or CoREST2, which may improve clinical outcomes for patients with mCRC.

The striking ethnic and racial disparities in breast cancer mortality are not explained fully by pathological or clinical features. Structural racism contributes to adverse conditions that promote cancer inequities, but the pathways by which this occurs are not fully understood. Social determinants of health (SDOH), such as economic status and access to care, account for a portion of this variability, yet interventions designed to mitigate these barriers have not consistently led to improved outcomes. Based on the current evidence from multiple disciplines, we describe a conceptual model in which structural racism and racial discrimination contribute to increased mortality risk in diverse groups of patients by promoting adverse SDOH that elevate exposure to environmental hazards and stress; these exposures in turn contribute to epigenetic and immune dysregulation, thereby altering breast cancer outcomes. Based on this model, opportunities and challenges arise for interventions to reduce racial and ethnic disparities in breast cancer mortality.

Resistance to endocrine therapies (ET) is common in estrogen receptor (ER) positive breast cancer, and most relapsed patients die with ET-resistant disease. While genetic mutations provide explanations for some relapses, mechanisms of resistance remain undefined in many cases. Drug-induced epigenetic reprogramming has been shown to provide possible routes to resistance. By analyzing histone H3 lysine 27 acetylation (H3K27ac) profiles and transcriptional reprogramming in models of ET resistance, we discovered that selective ER degraders (SERDs), such as fulvestrant, promote expression of VGLL1, a co-activator for TEAD transcription factors. VGLL1, acting via TEADs, promoted expression of genes that drive growth of fulvestrant-resistant breast cancer cells. Pharmacological disruption of VGLL1/TEAD4 interaction inhibited VGLL1/TEAD-induced transcriptional programs to prevent growth of resistant cells. EGFR was among the VGLL1/TEAD-regulated genes, and VGLL1-directed EGFR upregulation sensitized fulvestrant-resistant breast cancer cells to EGFR inhibitors. Taken together, these findings identify VGLL1 as a transcriptional driver in ET resistance and advance therapeutic possibilities for relapsed ER+ breast cancer patients.

Emerging evidence suggests that transforming growth factor β1 (TGFβ1) can inhibit angiogenesis, contradicting the coexistence of active angiogenesis and high abundance of TGFβ1 in the tumor microenvironment. Here, we investigated how tumors overcome the anti-angiogenic effect of TGFβ1. TGFβ1 treatment suppressed physiological angiogenesis in chick chorioallantoic membrane and zebrafish models but did not affect angiogenesis in mouse hepatoma xenografts. The suppressive effect of TGFβ1 on angiogenesis was recovered in mouse xenografts by a hypoxia-inducible factor 1α (HIF1α) inhibitor. In contrast, a HIF1α stabilizer abrogated angiogenesis in zebrafish, indicating that hypoxia may attenuate the anti-angiogenic role of TGFβ1. Under normoxic conditions, TGFβ1 inhibited angiogenesis by upregulating anti-angiogenic factor thrombospondin 1 (TSP1) in endothelial cells (ECs) via TGFβ type I receptor (TGFβR1)-SMAD2/3 signaling. In a hypoxic microenvironment, HIF1α induced microRNA-145 (miR145) expression; miR145 abolished the inhibitory effect of TGFβ1 on angiogenesis by binding and repressing SMAD2/3 expression and subsequently reducing TSP1 levels in ECs. Primary ECs isolated from human hepatocellular carcinoma (HCC) displayed increased miR145 and decreased SMAD3 and TSP1 compared to ECs from adjacent non-tumor livers. The reduced SMAD3 or TSP1 in ECs was associated with increased angiogenesis in HCC tissues. Collectively, this study identified that TGFβ1-TGFβR1-SMAD2/3-TSP1 signaling in ECs inhibits angiogenesis. This inhibition can be circumvented by a hypoxia-HIF1α-miR145 axis, elucidating a mechanism by which hypoxia promotes angiogenesis.

Tumor progression is an evolutionary process during which cells acquire distinct genetic alterations. Several cancer evolutionary studies reconstruct this evolutionary process by applying bulk DNA sequencing to a tumor sample to infer the presence of genetic alterations using various tumor evolutionary algorithms. Through a comprehensive benchmarking effort of these algorithms, a recent study by Salcedo and colleagues found that algorithmic and experimental choices are the main drivers of the accuracy of tumor evolution reconstruction, shedding new light on interpreting previous studies and suggesting a useful path forward for the research community.

Gastric cancer is an aggressive malignancy with poor patient outcomes. N-Acetyltransferase 10 (NAT10) is an acetyltransferase that has been reported to contribute to gastric cancer progression. In-depth investigation into the underlying molecular mechanisms driven by NAT10 could help identify therapeutic targets to improve gastric cancer treatment. In this study, we found that NAT10 forms condensates to regulate RNA dynamics and promote gastric cancer progression. In samples of patients with gastric cancer, elevated NAT10 expression correlated with an unfavorable prognosis, advanced disease stage, and metastasis. NAT10 enhanced the proliferation, migration, and invasion of gastric cancer cells; supported the growth of patient-derived organoids; and accelerated tumor development. A C-terminal intrinsically disordered region-mediated liquid-liquid phase separation of NAT10 and was essential for its tumor-promoting function in gastric cancer. Moreover, NAT10 interacted with the splicing factor serine/arginine-rich splicing factor 2 (SRSF2), leading to its acetylation and increased stability. Acetylated SRSF2 directly bound to the pre-mRNA of the m6A reader YTHDF1, resulting in enhanced YTHDF1 exon 4 skipping and upregulation of a short YTHDF1 transcript that could stimulate gastric cancer cell proliferation and migration. Furthermore, YTHDF1 exon 4 skipping correlated with NAT10 and SRSF2 expression and was associated with a more aggressive phenotype in samples of patients with gastric cancer. Together, this study uncovers the role of NAT10 liquid-liquid phase separation in modulating YTHDF1 splicing through SRSF2 acetylation to drive gastric cancer progression, providing insights into the oncogenic mechanism of NAT10. Significance: Phase separation of NAT10 enables acetylation of SRSF2 that enhances YTHDF1 exon 4 skipping, which is a tumor-promoting axis in gastric cancer that represents potential therapeutic targets and prognostic biomarkers.