Integrative clinical and preclinical studies identify FerroTerminator1 as a potent therapeutic drug for MASH.

The complex etiological factors associated with metabolic dysfunction-associated fatty liver disease (MAFLD), including perturbed iron homeostasis, and the unclear nature by which they contribute to disease progression have resulted in a limited number of effective therapeutic interventions. Here, we report that patients with metabolic dysfunction-associated steatohepatitis (MASH), a pathological subtype of MAFLD, exhibit excess hepatic iron and that it has a strong positive correlation with disease progression. FerroTerminator1 (FOT1) effectively reverses liver injury across multiple MASH models without notable toxic side effects compared with clinically approved iron chelators. Mechanistically, our multi-omics analyses reveal that FOT1 concurrently inhibits hepatic iron accumulation and c-Myc-Acsl4-triggered ferroptosis in various MASH models. Furthermore, MAFLD cohort studies suggest that serum ferritin levels might serve as a predictive biomarker for FOT1-based therapy in MASH. These findings provide compelling evidence to support FOT1 as a promising novel therapeutic option for all stages of MAFLD and for future clinical trials.

c-Myc-XRCC2-FOS axis promotes the proliferation and the resistance to Doxorubicin of NSCLC.

Lung cancer represents one of the most prevalent malignant neoplasms, commanding an alarming incidence and mortality rate globally. Non-small cell lung cancer (NSCLC), constituting approximately 80 %-90 % of all lung cancer cases, is the predominant pathological manifestation of this disease, with a disconcerting 5-year survival rate scarcely reaching 10 %. Extensive prior investigations have elucidated that the aberrant expression of X-ray repair cross-complementing gene 2 (XRCC2), a critical meiotic gene intricately involved in the DNA damage repair process, is intimately associated with tumorigenesis. Nevertheless, the precise roles and underlying mechanistic pathways of XRCC2 in NSCLC remain largely elusive. In the present study, we discerned an overexpression of XRCC2 within NSCLC patient tissues, particularly in high-grade samples, when juxtaposed with normal tissues. Targeted knockdown of XRCC2 notably impeded the proliferation of NSCLC both in vitro and in vivo. Comprehensive RNA sequencing and flow rescue assays unveiled that XRCC2 augments the proliferation of NSCLC cells through the down-regulation of FOS expression. Moreover, the c-Myc gene was definitively identified as an XRCC2 transcriptional factor by means of chromatin immunoprecipitation (ChIP) and luciferase reporter assays, whereby pharmacological attenuation of c-Myc expression, in conjunction with Doxorubicin, synergistically curtailed NSCLC cell growth both in vitro and in vivo. Collectively, our findings proffer critical insights into the novel c-Myc-XRCC2-FOS axis in promoting both proliferation and resistance to Doxorubicin in NSCLC cells, thereby extending a promising avenue for potential new diagnostic strategies and therapeutic interventions in NSCLC.

Targeting SMYD2 promotes ferroptosis and impacts the progression of pancreatic cancer through the c-Myc/NCOA4 axis-mediated ferritinophagy.

BACKGROUND: Pancreatic cancer (PC) is characterized by a poor prognosis and limited treatment options. Ferroptosis plays an important role in cancer, SET and MYND domain-containing protein 2 (SMYD2) is widely expressed in various cancers. However, the role of SMYD2 in regulating ferroptosis in PC remains unexplored. This study aimed to investigate the role of SMYD2 in mediating ferroptosis and its mechanistic implications in PC progression. METHODS: The levels of SMYD2, c-Myc, and NCOA4 were assessed in PC tissues, and peritumoral tissues. SMYD2 expression was further analyzed in human PC cell lines. In BxPC3 cells, the expression of c-Myc, NCOA4, autophagy-related proteins, and mitochondrial morphology, was evaluated following transfection with si-SMYD2 and treatment with autophagy inhibitors and ferroptosis inhibitors. Ferroptosis levels were quantified using flow cytometry and ELISA assays. RNA immunoprecipitation was conducted to elucidate the interaction between c-Myc and NCOA4 mRNA. A xenograft mouse model was constructed to validate the impact of SMYD2 knockdown on PC growth. RESULTS: SMYD2 and c-Myc were found to be highly expressed in PC tissues, while NCOA4 showed reduced expression. Among the PC cell lines studied, BxPC3 cells exhibited the highest SMYD2 expression. SMYD2 knockdown led to decreased c-Myc levels, increased NCOA4 expression, reduced autophagy-related protein expression, mitochondrial shrinkage, and heightened ferroptosis levels. Additionally, an interaction between c-Myc and NCOA4 was identified. In vivo, SMYD2 knockdown inhibited tumor growth. CONCLUSIONS: Targeting SMYD2 inhibits PC progression by promoting ferritinophagy-dependent ferroptosis through the c-Myc/NCOA4 axis. These findings provide insights into potential diagnostic and therapeutic strategies for PC.

Development of a fluorescent ligand that specifically binds to the c-MYC G-quadruplex by migrating the benzene group on a carbazole-benzothiazolium scaffold.

c-MYC is one of the most important oncogenes, which is overexpressed in many cancers, and is highly related to development, metastasis, and drug resistance of cancers. The G4 structure in the promoter of c-MYC oncogene contributes a lot to the gene transcriptional mechanism. Small-molecule ligands binding to the c-MYC G4 appear to be a new class of anticancer agents. However, selective ligands for the c-MYC G4 over other G4s have been rarely reported. In this study, we reported a novel fluorescent ligand by migrating the benzene group on a carbazole-benzothiazolium scaffold, which was demonstrated to exhibit considerable specificity to the c-MYC G4, which was distinguished from other small-molecule ligands. The further cellular experiments suggested that this ligand may indeed target the promoter G4 and cause apparent transcriptional inhibition of the c-MYC oncogene instead of other G4-mediated oncogenes, which thereby resulted in cancer cell growth inhibition. Collectively, this study provided a good example for developing specific c-MYC G4 ligands, which may further develop into an effective anticancer agent that inhibit the c-MYC expression.

Topical application of phenformin ameliorates the psoriasis-like inflammatory response via the inhibition of c-Myc expression in keratinocytes.

BACKGROUND: Psoriasis is a chronic inflammatory skin disease characterized by a complex pathogenesis involving various types of cells and cytokines. Among those, the pro-inflammatory cytokine IL-23/IL-17A axis plays a crucial role in the development and rapid progression of psoriasis. Phenformin, a derivative of metformin and a member of the biguanide class of drugs, exhibits superior anti-inflammatory and anti-tumor efficacy compared to metformin. However, the potential role of phenformin in anti-psoriatic skin inflammation has not been explored. METHODS: In this study, we utilized a mouse model of psoriasis and an in vitro model using human keratinocytes to investigate whether phenformin can suppress psoriasis-like inflammatory responses. RESULTS: Our results demonstrate that the topical application of phenformin significantly inhibited acute skin inflammatory responses in the psoriasis mouse model induced by imiquimod (IMQ). Additionally, phenformin suppressed the expression of psoriasis-related cytokines IL-17, IL-23, IL-8, and S100A8/S100A9 in an in vitro psoriatic keratinocyte model induced by IMQ. Furthermore, we found that IMQ-induced psoriatic skin and IMQ-treated keratinocytes exhibited high expression of the c-Myc gene, which was downregulated by phenformin. The c-Myc inhibitor JQ1 similarly inhibited the psoriatic inflammatory response and the expression of psoriasis-related cytokines in both in vitro and in vivo models. CONCLUSION: phenformin ameliorates the psoriasis-like inflammatory response by inhibiting c-Myc expression in keratinocytes, suggesting its potential as a topical drug for the treatment of psoriasis.

SOX2 represses c-MYC transcription by altering the co-activator landscape of the c-MYC super-enhancer and promoter regions.

Our previous studies determined that elevating SOX2 in a wide range of tumor cells leads to a reversible state of tumor growth arrest. Efforts to understand how tumor cell growth is inhibited led to the discovery of a SOX2:MYC axis that is responsible for downregulating c-MYC (MYC) when SOX2 is elevated. Although we had determined that elevating SOX2 downregulates MYC transcription, the mechanism responsible was not determined. Given the challenges of targeting MYC clinically, we set out to identify how elevating SOX2 downregulates MYC transcription. In this study, we focused on the MYC promoter region and an upstream region of the MYC locus that contains a MYC super-enhancer encompassing five MYC enhancers and which is associated with several cancers. Here we report that BRD4 and p300 associate with each of the MYC enhancers in the upstream MYC super-enhancer as well as the MYC promoter region and that elevating SOX2 decreases the recruitment of BRD4 and p300 to these sites. Additionally, we determined that elevating SOX2 leads to increases in the association of SOX2 and H3K27me3 within the MYC super-enhancer and the promoter region of MYC. Importantly, we conclude that the increases in SOX2 within the MYC super-enhancer precipitate a cascade of events that culminates in the repression of MYC transcription. Together, our studies identify a novel molecular mechanism able to regulate MYC transcription in two distinctly different tumor types and provide new mechanistic insights into the molecular interrelationships between two master regulators, SOX2 and MYC, widely involved in multiple cancers.

The Engineered Drug 3'UTRMYC1-18 Degrades the c-MYC-STAT5A/B-PD-L1 Complex In Vivo to Inhibit Metastatic Triple-Negative Breast Cancer.

c-MYC is overexpressed in 70% of human cancers, including triple-negative breast cancer (TNBC), yet there is no clinically approved drug that directly targets it. Here, we engineered the mRNA-stabilizing poly U sequences within the 3'UTR of c-MYC to specifically destabilize and promote the degradation of c-MYC transcripts. Interestingly, the engineered derivative outcompetes the endogenous overexpressed c-MYC mRNA, leading to reduced c-MYC mRNA and protein levels. The iron oxide nanocages (IO-nanocages) complexed with MYC-destabilizing constructs inhibited primary and metastatic tumors in mice bearing TNBC and significantly prolonged survival by degrading the c-MYC-STAT5A/B-PD-L1 complexes that drive c-MYC-positive TNBC. Taken together, we have described a novel therapy for c-MYC-driven TNBC and uncovered c-MYC-STAT5A/B-PD-L1 interaction as the target.

NCAPD2 augments the tumorigenesis and progression of human liver cancer via the PI3K­Akt­mTOR signaling pathway.

Non­SMC condensin I complex subunit D2 (NCAPD2) is a newly identified oncogene; however, the specific biological function and molecular mechanism of NCAPD2 in liver cancer progression remain unknown. In the present study, the aberrant expression of NCAPD2 in liver cancer was investigated using public tumor databases, including TNMplot, The Cancer Genome Atlas and the International Cancer Genome Consortium based on bioinformatics analyses, and it was validated using a clinical cohort. It was revealed that NCAPD2 was significantly upregulated in liver cancer tissues compared with in control liver tissues, and NCAPD2 served as an independent prognostic factor and predicted poor prognosis in liver cancer. In addition, the expression of NCAPD2 was positively correlated with the percentage of Ki67+ cells. Finally, single­cell sequencing data, gene­set enrichment analyses and in vitro investigations, including cell proliferation assay, Transwell assay, wound healing assay, cell cycle experiments, cell apoptosis assay and western blotting, were carried out in human liver cancer cell lines to assess the biological mechanisms of NCAPD2 in patients with liver cancer. The results revealed that the upregulation of NCAPD2 enhanced tumor cell proliferation, invasion and cell cycle progression at the G2/M­phase transition, and inhibited apoptosis in liver cancer cells. Furthermore, NCAPD2 overexpression was closely associated with the phosphatidylinositol 3­kinase (PI3K)­Akt­mammalian target of rapamycin (mTOR)/c­Myc signaling pathway and epithelial­mesenchymal transition (EMT) progression in HepG2 and Huh7 cells. In addition, upregulated NCAPD2 was shown to have adverse effects on overall survival and disease­specific survival in liver cancer. In conclusion, the overexpression of NCAPD2 was shown to lead to cell cycle progression at the G2/M­phase transition, activation of the PI3K­Akt­mTOR/c­Myc signaling pathway and EMT progression in human liver cancer cells.

CircXPO6 promotes breast cancer progression through competitively inhibiting the ubiquitination degradation of c-Myc.

The number of breast cancer (BC) patients is increasing year by year, which is severely endangering to human life and health. c-Myc is a transcription factor, studies have shown that it is a very significant factor in tumor progression, but how it is regulated in BC is still not well understood. Here, we used the RIP microarray sequencing to confirm circXPO6, which had a high affinity with c-Myc and highly expressed in triple-negative breast cancer (TNBC) tissues and cells. CircXPO6 overexpression promoted tumor growth in vivo and in vitro. Furthermore, circXPO6 largely promoted the expression of genes related to glucose metabolism, such as GLUT1, HK2, and MCT4 in TNBC cells. Finally, high levels of circXPO6 expression were found to be closely associated with malignant pathological factors, such as tumor size, lymph node metastasis, TNM staging, and histopathological grading of TNBC. Mechanistically, circXPO6 interacted with c-Myc to prevent speckle-type POZ-mediated c-Myc ubiquitination and degradation, thus promoting TNBC progression. Through the regulation of c-Myc-mediated signal transduction, circXPO6 plays a key role in TNBC progresses. This discovery can provide new ideas for TNBC molecular targeted therapy.

Inhibition of bromodomain and extra-terminal proteins targets constitutively active NFκB and STAT signaling in lymphoma and influences the expression of the antiapoptotic proteins BCL2A1 and c-MYC.

The antiapoptotic protein BCL2A1 is highly, but very heterogeneously expressed in Diffuse Large B-cell Lymphoma (DLBCL). Particularly in the context of resistance to current therapies, BCL2A1 appears to play an important role in protecting cancer cells from the induction of cell death. Reducing BCL2A1 levels may have therapeutic potential, however, no specific inhibitor is currently available. In this study, we hypothesized that the signaling network regulated by epigenetic readers may regulate the transcription of BCL2A1 and hence that inhibition of Bromodomain and Extra-Terminal (BET) proteins may reduce BCL2A1 expression thus leading to cell death in DLBCL cell lines. We found that the mechanisms of action of acetyl-lysine competitive BET inhibitors are different from those of proteolysis targeting chimeras (PROTACs) that induce the degradation of BET proteins. Both classes of BETi reduced the expression of BCL2A1 which coincided with a marked downregulation of c-MYC. Mechanistically, BET inhibition attenuated the constitutively active canonical nuclear factor kappa-light-chain-enhancer of activated B-cells (NFκB) signaling pathway and inhibited p65 activation. Furthermore, signal transducer of activated transcription (STAT) signaling was reduced by inhibiting BET proteins, targeting another pathway that is often constitutively active in DLBCL. Both pathways were also inhibited by the IκB kinase inhibitor TPCA-1, resulting in decreased BCL2A1 and c-MYC expression. Taken together, our study highlights a novel complex regulatory network that links BET proteins to both NFκB and STAT survival signaling pathways controlling both BCL2A1 and c-MYC expression in DLBCL.

Dexmedetomidine inhibits the migration, invasion, and glycolysis of glioblastoma cells by lactylation of c-myc.

BACKGROUND: Glioblastoma (GBM) is a brain tumor with poor prognosis. Dexmedetomidine (Dex) regulates the biological behaviors of tumor cells to accelerate or decelerate cancer progression. OBJECTIVE: We investigated the effects of Dex on the migration, invasion, and glycolysis in GBM. METHODS: The concentration of Dex was determined using the cell counting kit-8 assay. The impacts of Dex on biological behaviors of GBM cells were assessed using Transwell assay, XF96 extracellular flux analysis, and western blot. The expression of c-Myc was examined using reverse transcription-quantitative polymerase chain reaction. The lactylation or stability of c-Myc was measured by western blot after immunoprecipitation or cycloheximide treatment. RESULTS: We found that Dex (200 nM) inhibited GBM cell viability, migration, invasion, and glycolysis. C-Myc was highly expressed in GBM cells and was decreased by Dex treatment. Moreover, Dex suppressed lactylated c-Myc levels via suppressing glycolysis, thereby reducing the protein stability of c-Myc. Sodium lactate treatment abrogated the effects of Dex on the biological behaviors of GBM cells. CONCLUSION: Dex suppressed the migration, invasion, and glycolysis of GBM cells via inhibiting lactylation of c-Myc and suppressing the c-Myc stability, suggesting that Dex may be a novel therapeutic drug for GBM treatment.

TSA attenuates the progression of c-Myc-driven hepatocarcinogenesis by pAKT-ADH4 pathway.

Hepatocellular carcinoma (HCC) is the primary malignant tumor of the liver. c-Myc is one of the most common oncogenes in clinical settings, and amplified levels of c-Myc are frequently found in HCC. Histone deacetylase inhibitors (HDACi), such as Trichostatin A (TSA), hold enormous promise for the treatment of HCC. However, the potential and mechanism of TSA in the treatment of c-Myc-induced HCC are unclear. In this study, we investigated the effects of TSA treatment on a c-Myc-induced HCC model in mice. TSA treatment delayed the development of HCC, and liver function indicators such as ALT, AST, liver weight ratio, and spleen weight ratio demonstrated the effectiveness of TSA treatment. Oil red staining further demonstrated that TSA attenuated lipid accumulation in the HCC tissues of mice. Through mRNA sequencing, we identified that TSA mainly affected cell cycle and fatty acid degradation genes, with alcohol dehydrogenase 4 (ADH4) potentially being the core molecular downstream target. QPCR, immunohistochemistry, and western blot analysis revealed that ADH4 expression was repressed by c-Myc and restored after TSA treatment both in vitro and in vivo. Furthermore, we observed that the levels of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration increased after c-Myc transfection in liver cells but decreased after TSA intervention. The levels of phosphorylated protein kinase B (p-AKT) and p-mTOR were identified as targets regulated by TSA, and they governed the ADH4 expression and the downstream regulation of total NAD+ and NADH, NAD+, NAD+/NADH, and ATP concentration. Overall, our study suggests that TSA has a therapeutic effect on c-Myc-induced HCC through the AKT-mTOR-ADH4 pathway. These findings provide valuable insights into the potential treatment of HCC using TSA and shed light on the underlying molecular mechanisms involved.

Correlations between C-myc expression, BMI-1 expression, and vaginal microecology with HPV-DNA load in patients with different cervical lesions.

OBJECTIVE: To investigate the correlations between the expressions of proto-oncogenes C-myc and B-cell-specific Moloney leukemia virus integration site-1 (BMI-1), vaginal microecology, and human papillomavirus-DNA (HPV-DNA) load in patients with different cervical lesions. METHODS: A total of 51 patients with cervix squamous cell carcinoma (CSCC), 72 patients with cervical intraepithelial neoplasia (CIN) and 50 patients with normal cervix (NC) who were diagnosed or admitted between Jan. 1st 2020 and Dec. 31st 2022 at the Suzhou Hospital of Integrated Traditional Chinese and Western Medicine were selected and divided into three groups, i.e., the CSCC group, the CIN group and the NC group, for a retrospective analysis. Hybrid capture 2 (hc2) was used to detect the HPV-DNA load in each group. Immunohistochemistry was performed to detect C-myc and BMI-1 expressions in each group. The indicators of vaginal microecology in patients were compared among groups to analyze the correlations between C-myc, BMI-1 expressions, vaginal microecology and HPV-DNA load. RESULTS: The HPV-DNA load and expression levels of positive C-myc and BMI-1 in the CSCC group were all higher than those of the CIN and NC groups (P<0.05). The detection rate of lactobacillus in the CSCC group was lower than that of the CIN and NC groups. The percentages of leukocyte esterase (LE) positivity and pH ≥4.6 were higher in the CSCC group than those in the CIN and NC groups (P<0.05). The difference in the detection rate of spores among the three groups was not significant (P>0.05). Both C-myc and BMI-1 scores were positively correlated with HPV-DNA load in the 173 samples. CONCLUSION: The proto-oncogenes C-myc and BMI-1 were highly expressed in the cervical tissues of CIN and CSCC patients, whose vaginal microecology was also altered. Both may play an important role in the progression of cervical lesions.

ROCK1 regulates glycolysis in pancreatic cancer via the c-MYC/PFKFB3 pathway.

BACKGROUND: Dysregulation of Rho-associated coiled coil-containing protein kinases (ROCKs) is involved in the metastasis and progression of various malignant tumors. However, how one of the isomers, ROCK1, regulates glycolysis in tumor cells is incompletely understood. Here, we attempted to elucidate how ROCK1 influences pancreatic cancer (PC) progression by regulating glycolytic activity. METHODS: The biological function of ROCK1 was analyzed in vitro by establishing a silenced cell model. Coimmunoprecipitation confirmed the direct binding between ROCK1 and c-MYC, and a luciferase reporter assay revealed the binding of c-MYC to the promoter of the PFKFB3 gene. These results were verified in animal experiments. RESULTS: ROCK1 was highly expressed in PC tissues and enriched in the cytoplasm, and its high expression was associated with a poor prognosis. Silencing ROCK1 inhibited the proliferation and migration of PC cells and promoted their apoptosis. Mechanistically, ROCK1 directly interacted with c-MYC, promoted its phosphorylation (Ser 62) and suppressed its degradation, thereby increasing the transcription of the key glycolysis regulatory factor PFKFB3, enhancing glycolytic activity and promoting PC growth. Silencing ROCK1 increased gemcitabine (GEM) sensitivity in vivo and in vitro. CONCLUSIONS: ROCK1 promotes glycolytic activity in PC cells and promotes PC tumor growth through the c-MYC/PFKFB3 signaling pathway. ROCK1 knockdown can inhibit PC tumor growth in vivo and increase the GEM sensitivity of PC tumors, providing a crucial clinical therapeutic strategy for PC.

SAHA/5-AZA Enhances Acetylation and Degradation of mutp53, Upregulates p21 and Downregulates c-Myc and BRCA-1 in Pancreatic Cancer Cells.

Epigenetic changes are common in cancer and include aberrant DNA methylation and histone modifications, including both acetylation or methylation. DNA methylation in the promoter regions and histone deacetylation are usually accompanied by gene silencing, and may lead to the suppression of tumor suppressors in cancer cells. An interaction between epigenetic pathways has been reported that could be exploited to more efficiently target aggressive cancer cells, particularly those against which current treatments usually fail, such as pancreatic cancer. In this study, we explored the possibility to combine the DNA demethylating agent 5-AZA with HDAC inhibitor SAHA to treat pancreatic cancer cell lines, focusing on the acetylation of mutp53 and the consequences on its stability, as well as on the interaction of this protein with c-myc and BRCA-1, key molecules in cancer survival. The results obtained suggest that SAHA/5-AZA combination was more effective than single treatments to promote the degradation of mutp53, to upregulate p21 and downregulate c-Myc and BRCA-1, thus increasing DNA damage and cytotoxicity in pancreatic cancer cells.

ZNF300 promotes proliferation and migration of hepatocellular carcinoma by upregulating c-MYC gene expression.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Currently, the treatments of HCC are limited to surgical resection and liver transplantation, and there is no effective systemic therapy. OBJECTIVES: To investigate the regulatory mechanism of zinc finger protein 300 (ZNF300) in hepatocellular carcinoma (HCC). METHODS: The expressions of ZNF300 in HCC tissue samples and HCC cell lines (Hep3B, Huh7, SNU-387) were detected. ZNF300 overexpression vector (ZNF300) or shRNAZNF300 (shZNF300) was transfected into HCC cells to increase or inhibit ZNF300 expression. 5-Ethynyl-2'-deoxyuridine assay (EdU), cell counting kit-8 assay (CCK-8) and transwell invasion assay were conducted to evaluate the proliferation, viability, migration, and invasion of HCC cells respectively. The expressions of tumor migration and invasion related proteins (matrix metallopeptidase 2 (MMP-2) and MMP-9), c-MYC, and MAPK/ERK signaling pathway related molecules (p-ERK1/2, ERK1/2, p-P38, P38) were determined by western blotting. Hep3B cells transfected with shZNF300 were subcutaneously injected into nude mice to perform tumor xenograft experiment. Tumor volume and weight were measured. RESULTS: ZNF300 was upregulated in HCC tissues and cells. The expressions of MMP-2 and MMP-9 were increased in HCC cells after transfecting with ZNF300 but reduced in HCC cells transfected with shZNF300. Downregulation of ZNF300 inhibited HCC cell proliferation, migration, and invasion, while overexpression of ZNF300 showed the opposite effects. Moreover, the expressions of c-MYC and MAPK/ERK signaling pathway related molecules were increased after overexpression of ZNF300 but reduced after downregulating ZNF300. In tumor xenograft experiment, downregulation of ZNF300 reduced tumor volume and weight. CONCLUSION: The present study proved that downregulation of ZNF300 inhibited HCC growth by reducing c-MYC expression and MAPK/ERK signaling pathway.

Inhibition of KIF20A enhances the immunotherapeutic effect of hepatocellular carcinoma by enhancing c-Myc ubiquitination.

Immune therapy has significantly improved the prognosis of hepatocellular carcinoma (HCC) patients, yet its efficacy remains limited, underscoring the urgency to identify new therapeutic targets and biomarkers. Here, we investigated the pathological and physiological roles of KIF20A and assess its potential in enhancing HCC treatment efficacy when combined with PD-1 inhibitors. We initially assess KIF20A's oncogenic function using liver-specific KIF20A knockout (Kif20a CKO) mouse models and orthotopic xenografts. Subsequently, we establish a regulatory axis involving KIF20A, FBXW7, and c-Myc, validated through construction of c-Myc splicing mutants. Large-scale clinical immunohistochemistry (IHC) analyses confirm the pathological relevance of the KIF20A-FBXW7-c-Myc axis in HCC. We demonstrate that KIF20A overexpression correlates with poor prognosis in HCC by competitively inhibiting FBXW7-mediated degradation of c-Myc, thereby promoting glycolysis and enhancing tumor proliferation. Conversely, KIF20A downregulation suppresses these effects, impairing tumor growth through c-Myc downregulation. Notably, KIF20A inhibition attenuates c-Myc-induced MMR expression, associated with improved prognosis in HCC patients receiving PD-1 inhibitor therapy. Furthermore, in Kif20a CKO HCC mouse models, we observe synergistic effects between Kif20a knockout and anti-PD-1 antibodies, significantly enhancing immunotherapeutic efficacy against HCC. Our findings suggest that targeting the KIF20A-c-Myc axis could identify HCC patients likely to benefit from anti-PD-1 therapy. In conclusion, we propose that combining KIF20A inhibitors with anti-PD-1 treatment represents a promising therapeutic strategy for HCC, offering new avenues for clinical development and patient stratification.

USP11 promotes prostate cancer progression by up-regulating AR and c-Myc activity.

Androgen receptor (AR) is a main driver for castration-resistant prostate cancer (CRPC). c-Myc is an oncogene underlying prostate tumorigenesis. Here, we find that the deubiquitinase USP11 targets both AR and c-Myc in prostate cancer (PCa). USP11 expression was up-regulated in metastatic PCa and CRPC. USP11 knockdown (KD) significantly inhibited PCa cell growth. Our RNA-seq studies revealed AR and c-Myc as the top transcription factors altered after USP11 KD. ChIP-seq analysis showed that either USP11 KD or replacement of endogenous USP11 with a catalytic-inactive USP11 mutant significantly decreased chromatin binding by AR and c-Myc. We find that USP11 employs two mechanisms to up-regulate AR and c-Myc levels: namely, deubiquitination of AR and c-Myc proteins to increase their stability and deubiquitination of H2A-K119Ub, a repressive histone mark, on promoters of AR and c-Myc genes to increase their transcription. AR and c-Myc reexpression in USP11-KD PCa cells partly rescued cell growth defects. Thus, our studies reveal a tumor-promoting role for USP11 in aggressive PCa through upregulation of AR and c-Myc activities and support USP11 as a potential target against PCa.

Vitexicarpin suppresses malignant progression of colorectal cancer through affecting c-Myc ubiquitination by targeting IMPDH2.

BACKGROUND: Colorectal cancer (CRC) is the second most common cause of cancer-related mortality and is characterised by extensive invasive and metastatic potential. Previous studies have shown that vitexicarpin extracted from the fruits of Vitex rotundifolia can impede tumour progression. However, the molecular mechanisms involved in CRC treatment are still not fully established. PURPOSE: Our study aimed to investigate the anticancer activity, targets, and molecular mechanisms of vitexicarpin in CRC hoping to provide novel therapies for patients with CRC. STUDY DESIGN/METHODS: The impact of vitexicarpin on CRC was assessed through various experiments including MTT, clone formation, EDU, cell cycle, and apoptosis assays, as well as a tumour xenograft model. CETSA, label-free quantitative proteomics, and Biacore were used to identify the vitexicarpin targets. WB, Co-IP, Ubiquitination assay, IF, molecular docking, MST, and cell transfection were used to investigate the mechanism of action of vitexicarpin in CRC cells. Furthermore, we analysed the expression patterns and correlation of target proteins in TCGA and GEPIA datasets and clinical samples. Finally, wound healing, Transwell, tail vein injection model, and tissue section staining were used to demonstrate the antimetastatic effect of vitexicarpin on CRC in vitro and in vivo. RESULTS: Our findings demonstrated that vitexicarpin exhibits anticancer activity by directly binding to inosine monophosphate dehydrogenase 2 (IMPDH2) and that it promotes c-Myc ubiquitination by disrupting the interaction between IMPDH2 and c-Myc, leading to epithelial-mesenchymal transition (EMT) inhibition. Vitexicarpin hinders the migration and invasion of CRC cells by reversing EMT both in vitro and in vivo. Additionally, these results were validated by the overexpression and knockdown of IMPDH2 in CRC cells. CONCLUSION: These results demonstrated that vitexicarpin regulates the interaction between IMPDH2 and c-Myc to inhibit CRC proliferation and metastasis both in vitro and in vivo. These discoveries introduce potential molecular targets for CRC treatment and shed light on new mechanisms for c-Myc regulation in tumours.

DSG2 and c-MYC Interact to Regulate the Expression of ADAM17 and Promote the Development of Cervical Cancer.

Purpose: To explore the effect of DSG2 on the growth of cervical cancer cells and its possible regulatory mechanism. Methods: The expression levels and survival prognosis of DSG2 and ADAM17 in cervical squamous cell carcinoma tissues and adjacent normal tissues were analyzed by bioinformatics. CCK-8 assay, colony formation assay and Transwell assay were used to detect the effects of DSG2 on the proliferative activity, colony formation ability and migration ability of SiHa and Hela cells. The effect of DSG 2 on the level of ADAM17 transcription and translation was detected by qPCR and Western blot experiments. The interaction between DSG2 and c-MYC was detected by immunocoprecipitation. c-MYC inhibitors were used in HeLa cells overexpressing DSG2 to analyze the effects of DSG2 and c-MYC on proliferation, colony formation and migration of Hela cells, as well as the regulation of ADAM17 expression. Results: DSG2 was highly expressed in cervical squamous cell carcinoma compared with normal tissues (P<0.05), and high DSG2 expression suggested poor overall survival (P<0.05). After DSG2 knockdown, the proliferative activity, colony formation and migration ability of SiHa and Hela cells were significantly decreased (P<0.05). Compared with adjacent normal tissues, ADAM17 was highly expressed in cervical squamous cell carcinoma (P<0.05), and high ADAM17 expression suggested poor overall survival in cervical cancer patients (P<0.05). The results of immunocoprecipitation showed the interaction between DSG2 and c-MYC. Compared with DSG2 overexpression group, DSG2 overexpression combined with c-MYC inhibition group significantly decreased cell proliferation, migration and ADAM17 expression (P < 0.05). Conclusion: DSG2 is highly expressed in cervical cancer, and inhibition of DSG2 expression can reduce the proliferation and migration ability of cervical cancer cells, which may be related to the regulation of ADAM17 expression through c-MYC interaction.