Citations

Abstract Although the Sonic hedgehog (SHH) signaling pathway has been implicated in promoting malignant phenotypes of prostate cancer, details on how it is activated and exerts its oncogenic role during prostate cancer development and progression is less clear. Here, we show that GLI3, a key SHH pathway effector, is transcriptionally upregulated during androgen deprivation and posttranslationally stabilized in prostate cancer cells by mutation of speckle-type POZ protein (SPOP). GLI3 is a substrate of SPOP-mediated proteasomal degradation in prostate cancer cells and prostate cancer driver mutations in SPOP abrogate GLI3 degradation. Functionally, GLI3 is necessary and sufficient for the growth and migration of androgen receptor (AR)–positive prostate cancer cells, particularly under androgen-depleted conditions. Importantly, we demonstrate that GLI3 physically interacts and functionally cooperates with AR to enrich an AR-dependent gene expression program leading to castration-resistant growth of xenografted prostate tumors. Finally, we identify an AR/GLI3 coregulated gene signature that is highly correlated with castration-resistant metastatic prostate cancer and predictive of disease recurrence. Together, these findings reveal that hyperactivated GLI3 promotes castration-resistant growth of prostate cancer and provide a rationale for therapeutic targeting of GLI3 in patients with castration-resistant prostate cancer (CRPC). Implications: We describe two clinically relevant mechanisms leading to hyperactivated GLI3 signaling and enhanced AR/GLI3 cross-talk, suggesting that GLI3-specific inhibitors might prove effective to block prostate cancer development or delay CRPC.

AbstractObjectivesStudies on the association between metformin use and the risk of oesophageal cancer (OC) have generated controversial findings. This updated meta-analysis was conducted to reassess the effects of metformin on OC.MethodsA comprehensive search strategy was conducted to select relevant studies from origination to February 2021. Heterogeneity was evaluated through the Q test and I2 statistics. HRs and 95% CIs were pooled through either random-effect or fixed-effect models. Meta-regression, subgroup analyses, sensitivity analysis and publication bias diagnosis were also performed.ResultsSeven studies with 5 426 343 subjects were included. Metformin use was associated with reduced risk of OC (HR=0.69, 95% CI 0.54 to 0.87, p<0.001). Sensitivity analysis suggested that the results were relatively stable.ConclusionMetformin is associated with a reduced risk of OC. More well-designed studies are still needed to further elaborate on these associations.PROSPERO registration numberCRD42021237127.

Significance The sorting nexin proteins are critical for endosomal trafficking and signaling. SNX17 and SNX27 are two SNX proteins displaying high similarity in domain structure, including a common FERM domain; however, they mediate distinct endocytic recycling pathways. We now solve this mystery by demonstrating that the FERM domains of SNX17 and SNX27 have different functions. Whereas the FERM domain of SNX17 recognizes the NPxY/NxxY motif, the same domain in SNX27 binds to a novel “DLF” motif within the N termini of SNX1/2. The interaction between SNX27 and SNX1/2 not only helps efficient retrieval of multiple cargoes but also promotes endosomal recruitment of SNX27. We further demonstrate that the SNX27–SNX1/2 interaction is crucial to neuronal growth and brain development in zebrafish.

PURPOSE This phase I/II study evaluated tremelimumab (anticytotoxic T-lymphocyte–associated antigen-4 monoclonal antibody) and durvalumab (antiprogrammed death ligand-1 monoclonal antibody) as monotherapies and in combination for patients with unresectable hepatocellular carcinoma (HCC), including a novel regimen featuring a single, priming dose of tremelimumab (ClinicalTrials.gov identifier: NCT02519348 ). PATIENTS AND METHODS Patients with HCC who had progressed on, were intolerant to, or refused sorafenib were randomly assigned to receive T300 + D (tremelimumab 300 mg plus durvalumab 1,500 mg [one dose each during the first cycle] followed by durvalumab 1,500 mg once every 4 weeks), durvalumab monotherapy (1,500 mg once every 4 weeks), tremelimumab monotherapy (750 mg once every 4 weeks [seven doses] and then once every 12 weeks), or T75 + D (tremelimumab 75 mg once every 4 weeks plus durvalumab 1,500 mg once every 4 weeks [four doses] followed by durvalumab 1,500 mg once every 4 weeks). Safety was the primary end point. Secondary end points included objective response rate (ORR) by Response Evaluation Criteria in Solid Tumors v1.1 and overall survival; exploratory end points included circulating lymphocyte profiles. RESULTS A total of 332 patients were enrolled (T300 + D, n = 75; durvalumab, n = 104; tremelimumab, n = 69; and T75 + D, n = 84). Tolerability was acceptable across arms, with grade ≥ 3 treatment-related adverse events occurring in 37.8%, 20.8%, 43.5%, and 24.4%, respectively. Confirmed ORRs (95% CI) were 24.0% (14.9 to 35.3), 10.6% (5.4 to 18.1), 7.2% (2.4 to 16.1), and 9.5% (4.2 to 17.9), respectively. An early expansion of CD8+ lymphocytes was associated with response across arms, with highest proliferating CD8+ lymphocyte levels occurring in the T300 + D arm. The median (95% CI) overall survival was 18.7 (10.8 to 27.3), 13.6 (8.7 to 17.6), 15.1 (11.3 to 20.5), and 11.3 (8.4 to 15.0) months in the T300 + D, durvalumab, tremelimumab, and T75 + D arms, respectively. CONCLUSION All regimens were found to be tolerable and clinically active; however, the T300 + D regimen demonstrated the most encouraging benefit-risk profile. The unique pharmacodynamic activity and association with ORR of the T300 + D regimen further support its continued evaluation in HCC.

Abstract Cell fate conversion by overexpressing defined factors is a powerful tool in regenerative medicine. However, identifying key factors for cell fate conversion requires laborious experimental efforts; thus, many of such conversions have not been achieved yet. Nevertheless, cell fate conversions found in many published studies were incomplete as the expression of important gene sets could not be manipulated thoroughly. Therefore, the identification of master transcription factors for complete and efficient conversion is crucial to render this technology more applicable clinically. In the past decade, systematic analyses on various single-cell and bulk OMICs data have uncovered numerous gene regulatory mechanisms, and made it possible to predict master gene regulators during cell fate conversion. By virtue of the sparse structure of master transcription factors and the group structure of their simultaneous regulatory effects on the cell fate conversion process, this study introduces a novel computational method predicting master transcription factors based on group sparse optimization technique integrating data from multi-OMICs levels, which can be applicable to both single-cell and bulk OMICs data with a high tolerance of data sparsity. When it is compared with current prediction methods by cross-referencing published and validated master transcription factors, it possesses superior performance. In short, this method facilitates fast identification of key regulators, give raise to the possibility of higher successful conversion rate and in the hope of reducing experimental cost.

Abstract High-risk neuroblastoma remains therapeutically challenging to treat, and the mechanisms promoting disease aggression are poorly understood. Here, we show that elevated expression of dihydrolipoamide S-succinyltransferase (DLST) predicts poor treatment outcome and aggressive disease in patients with neuroblastoma. DLST is an E2 component of the α-ketoglutarate (αKG) dehydrogenase complex, which governs the entry of glutamine into the tricarboxylic acid cycle (TCA) for oxidative decarboxylation. During this irreversible step, αKG is converted into succinyl-CoA, producing NADH for oxidative phosphorylation (OXPHOS). Utilizing a zebrafish model of MYCN-driven neuroblastoma, we demonstrate that even modest increases in DLST expression promote tumor aggression, while monoallelic dlst loss impedes disease initiation and progression. DLST depletion in human MYCN-amplified neuroblastoma cells minimally affected glutamine anaplerosis and did not alter TCA cycle metabolites other than αKG. However, DLST loss significantly suppressed NADH production and impaired OXPHOS, leading to growth arrest and apoptosis of neuroblastoma cells. In addition, multiple inhibitors targeting the electron transport chain, including the potent IACS-010759 that is currently in clinical testing for other cancers, efficiently reduced neuroblastoma proliferation in vitro. IACS-010759 also suppressed tumor growth in zebrafish and mouse xenograft models of high-risk neuroblastoma. Together, these results demonstrate that DLST promotes neuroblastoma aggression and unveils OXPHOS as an essential contributor to high-risk neuroblastoma. Significance: These findings demonstrate a novel role for DLST in neuroblastoma aggression and identify the OXPHOS inhibitor IACS-010759 as a potential therapeutic strategy for this deadly disease.

Abstract Background: Use of menopausal hormone therapy (MHT) is associated with increased risk for breast cancer. However, the relevant mechanisms and its interaction with genetic variants are not fully understood. Methods: We conducted a genome-wide interaction analysis between MHT use and genetic variants for breast cancer risk in 27,585 cases and 34,785 controls from 26 observational studies. All women were post-menopausal and of European ancestry. Multivariable logistic regression models were used to test for multiplicative interactions between genetic variants and current MHT use. We considered interaction p-values<5x10-8 as genome-wide significant, and p-values<1x10-5 as suggestive. Linkage disequilibrium (LD)-based clumping was performed to identify independent candidate variants.Results: None of the 9.7 million genetic variants tested for interactions with MHT use reached genome-wide significance. Only 213 variants, representing 18 independent loci, had p-values<1x105. The strongest evidence was found for rs4674019 (p-value=2.27x10-7), which showed genome-wide significant interaction (p-value=3.8x10-8) with current MHT use when analysis was restricted to population-based studies only. Limiting the analyses to combined estrogen-progesterone MHT use only or to estrogen receptor (ER) positive cases did not identify any genome-wide significant evidence of interactions. Conclusions: In this large genome-wide SNP-MHT interaction study of breast cancer, we found no strong support for common genetic variants modifying the effect of MHT on breast cancer risk. These results suggest that common genetic variation has limited impact on the observed MHT–breast cancer risk association.