Oncogenic H-RAS induces metformin resistance in head and neck cancer by promoting glycolytic metabolism.

Metformin administration has recently emerged as a candidate strategy for the prevention of head and neck squamous cell carcinoma (HNSCC). However, the intricate relationship between genetic alterations in HNSCC and metformin sensitivity is still poorly understood, which prevents the stratifications of patients harboring oral premalignant lesions that may benefit from the chemopreventive activity of metformin. In this study, we investigate the impact of prevalent mutations in HNSCC in response to metformin. Notably, we found that the expression of oncogenic HRAS mutants confers resistance to metformin in isogenic HNSCC cell systems and that HNSCC cells harboring endogenous HRAS mutations display limited sensitivity to metformin. Remarkably, we found that metformin fails to reduce activation of the mTOR pathway in HRAS oncogene expressing HNSCC cells in vitro and in vivo, correlating with reduced tumor suppressive activity. Mechanistically, we found that this process depends on the ability of HRAS to enhance glycolytic metabolism, thereby suppressing the requirement of oxidative phosphorylation to maintain the cellular energetic balance. Overall, our study revealed that HNSCC cells with oncogenic HRAS mutations exhibit diminished metformin sensitivity, thus shedding light on a potential mechanism of treatment resistance. This finding may also help explain the limited clinical responses to metformin in cancers with RAS mutations. Ultimately, our study underscores the importance of understanding the impact of the genetic landscape in tailoring precision cancer preventive approaches in the context of HNSCC and other cancers that are characterized by the presence of a defined premalignant state and, therefore, amenable for cancer interception strategies.

A Kinome-Wide Synthetic Lethal CRISPR/Cas9 Screen Reveals That mTOR Inhibition Prevents Adaptive Resistance to CDK4/CDK6 Blockade in HNSCC.

The comprehensive genomic analysis of the head and neck squamous cell carcinoma (HNSCC) oncogenome revealed the frequent loss of p16INK4A (CDKN2A) and amplification of cyclin D1 genes in most human papillomavirus-negative HNSCC lesions. However, cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have shown modest effects in the clinic. The aberrant activation of the PI3K/mTOR pathway is highly prevalent in HNSCC, and recent clinical trials have shown promising clinical efficacy of mTOR inhibitors (mTORi) in the neoadjuvant and adjuvant settings but not in patients with advanced HNSCC. By implementing a kinome-wide CRISPR/Cas9 screen, we identified cell-cycle inhibition as a synthetic lethal target for mTORis. A combination of mTORi and palbociclib, a CDK4/6-specific inhibitor, showed strong synergism in HNSCC-derived cells in vitro and in vivo. Remarkably, we found that an adaptive increase in cyclin E1 (CCNE1) expression upon palbociclib treatment underlies the rapid acquired resistance to this CDK4/6 inhibitor. Mechanistically, mTORi inhibits the formation of eIF4G-CCNE1 mRNA complexes, with the consequent reduction in mRNA translation and CCNE1 protein expression. Our findings suggest that mTORi reverts the adaptive resistance to palbociclib. This provides a multimodal therapeutic option for HNSCC by cotargeting mTOR and CDK4/6, which in turn may halt the emergence of palbociclib resistance. SIGNIFICANCE: A kinome-wide CRISPR/Cas9 screen identified cell-cycle inhibition as a synthetic lethal target of mTORis. A combination of mTORi and palbociclib, a CDK4/6-specific inhibitor, showed strong synergistic effects in HNSCC. Mechanistically, mTORis inhibited palbociclib-induced increase in CCNE1.

A genome-wide CRISPR screen reveals that antagonism of glutamine metabolism sensitizes head and neck squamous cell carcinoma to ferroptotic cell death.

Glutamine is a conditionally essential amino acid for the growth and survival of rapidly proliferating cancer cells. Many cancers are addicted to glutamine, and as a result, targeting glutamine metabolism has been explored clinically as a therapeutic approach. Glutamine-catalyzing enzymes are highly expressed in primary and metastatic head and neck squamous cell carcinoma (HNSCC). However, the nature of the glutamine-associated pathways in this aggressive cancer type has not been elucidated. Here, we explored the therapeutic potential of a broad glutamine antagonist, DRP-104 (sirpiglenastat), in HNSCC tumors and aimed at shedding light on glutamine-dependent pathways in this disease. We observed a potent antitumoral effect of sirpiglenastat in HPV- and HPV + HNSCC xenografts. We conducted a whole-genome CRISPR screen and metabolomics analyses to identify mechanisms of sensitivity and resistance to glutamine metabolism blockade. These approaches revealed that glutamine metabolism blockade results in the rapid buildup of polyunsaturated fatty acids (PUFAs) via autophagy nutrient-sensing pathways. Finally, our analysis demonstrated that GPX4 mediates the protection of HNSCC cells from accumulating toxic lipid peroxides; hence, glutamine blockade sensitizes HNSCC cells to ferroptosis cell death upon GPX4 inhibition. These findings demonstrate the therapeutic potential of sirpiglenastat in HNSCC and establish a novel link between glutamine metabolism and ferroptosis, which may be uniquely translated into targeted glutamine-ferroptosis combination therapies.

CHEK2 knockout is a therapeutic target for TP53-mutated hepatocellular carcinoma.

Currently, there is still a lack of novel and effective drug targets to improve the prognosis of hepatocellular carcinoma (HCC). Additionally, the role of CHEK2 in HCC has not been reported yet. The eQTLgen database and two HCC Genome-Wide Association Study (GWAS) datasets (ieu-b-4953, ICD10 C22.0) were used to find the drug target: CHEK2. Next, Colony, Edu, ß-gal, and cell cycle analysis were facilitated to evaluate the role of CHEK2 knockout in HCC. In addition, Nultin-3 was added to evaluate the apoptosis of TP53-mutated HCC cells with CHEK2 knockout. Furthermore, MitoSox, electron microscopy, mitochondrial ATP, and NADH+/NADH levels were assessed in the CHEK2 knockout HCC cells with or without Metformin. Finally, cell-derived tumor xenograft was used to evaluate the role of CHEK2 knockout in vivo. We initially identified a potential drug target, CHEK2, through GWAS data analysis. Furthermore, we observed a significant upregulation of CHEK2 expression in HCC, which was found to be correlated with a poor prognosis. Subsequently, the results indicated that knocking out CHEK2 selectively affects the proliferation, cell cycle, senescence, and apoptosis of TP53-mutant HCC cells. Additionally, the introduction of Nultin-3 further intensified the functional impact on TP53-mutant cells. Then ClusterProfiler results showed high CHEK2 and TP53 mutation group was positively enriched in the mitochondrial ATP pathway. Then we used MitoSox, electron microscopy, mitochondrial ATP, and NADH + /NADH assay and found knockout of CHECK could induce the ATP pathway to inhibit the growth of HCC. Our research introduces a novel drug target for TP53-mutant HCC cells via mitochondrial ATP, addressing the limitation of Nultin-3 as a standalone treatment that does not induce tumor cell death.

Gαs is dispensable for ß-arrestin coupling but dictates GRK selectivity and is predominant for gene expression regulation by ß2-adrenergic receptor.

ß-arrestins play a key role in G protein-coupled receptor (GPCR) internalization, trafficking, and signaling. Whether ß-arrestins act independently of G protein-mediated signaling has not been fully elucidated. Studies using genome-editing approaches revealed that whereas G proteins are essential for mitogen-activated protein kinase activation by GPCRs., ß-arrestins play a more prominent role in signal compartmentalization. However, in the absence of G proteins, GPCRs may not activate ß-arrestins, thereby limiting the ability to distinguish G protein from ß-arrestin-mediated signaling events. We used ß2-adrenergic receptor (ß2AR) and its ß2AR-C tail mutant expressed in human embryonic kidney 293 cells wildtype or CRISPR-Cas9 gene edited for Gαs, ß-arrestin1/2, or GPCR kinases 2/3/5/6 in combination with arrestin conformational sensors to elucidate the interplay between Gαs and ß-arrestins in controlling gene expression. We found that Gαs is not required for ß2AR and ß-arrestin conformational changes, ß-arrestin recruitment, and receptor internalization, but that Gαs dictates the GPCR kinase isoforms involved in ß-arrestin recruitment. By RNA-Seq analysis, we found that protein kinase A and mitogen-activated protein kinase gene signatures were activated by stimulation of ß2AR in wildtype and ß-arrestin1/2-KO cells but absent in Gαs-KO cells. These results were validated by re-expressing Gαs in the corresponding KO cells and silencing ß-arrestins in wildtype cells. These findings were extended to cellular systems expressing endogenous levels of ß2AR. Overall, our results support that Gs is essential for ß2AR-promoted protein kinase A and mitogen-activated protein kinase gene expression signatures, whereas ß-arrestins initiate signaling events modulating Gαs-driven nuclear transcriptional activity.

Acid-degradable nanocomposite hydrogel and glucose oxidase combination for killing bacterial with photothermal augmented chemodynamic therapy.

Bacterial infection often delays diabetic wound healing, and even causes serious life-threatening complications. Herein, we successfully developed a Cu2O/Pt nanocubes-dopping alginate (ALG)- hyaluronic acid (HA) hydrogel (Cu2O/Pt hydrogel) by simple assembly of the Cu2O/Pt nanocubes and the ALG-HA mixture. The Cu2O/Pt hydrogel combined with the glucose oxidase (GOx) can be used for photothermal- and starving-enhanced chemodynamic therapy (CDT) against Gram-negative and Gram-positive bacteria. The GOx can catalyze the glucose to produce gluconic acid and H2O2 for starvation therapy, following which the released Cu2O/Pt nanocubes react with H2O2 in the acidic microenvironment to generate highly cytotoxic hydroxyl radicals (·OH) for CDT. Additionally, the Cu2O/Pt hydrogel can release copper ions gradually with the decrease of pH induced by gluconic acid, which can increase the protein expression and secretion of vascular endothelial growth factor (VEGF) and promote endothelial cell proliferation, migration and angiogenesis, subsequently promoting diabetic wound healing in rats. Our results suggested that the Cu2O/Pt hydrogel combined with GOx may be a potential therapeutic approach for treating the infected diabetic wound.

Comparing Prognosis Associated with Partial Cystectomy and Trimodal Therapy for Muscle-Invasive Bladder Cancer Patients.

OBJECTIVE: This study aimed to compare the survival outcomes between trimodal therapy (TT) and partial cystectomy (PC) in muscle-invasive bladder cancer (MIBC) patients. METHODS: The data of 13,096 patients with MIBC diagnosed between 2004 and 2015 were retrieved from the Surveillance, Epidemiology, and End Results database. Among them, 4,041 patients underwent TT and 1,670 patients underwent PC. Propensity score matching was performed to balance the characteristics between the 2 treatment groups. A multivariate Cox regression analysis model and a competing risk model were used to evaluate overall survival (OS) and cancer-specific survival. Cumulative incidence survival curves were obtained using the Kaplan-Meier method. RESULTS: Results of multivariate Cox analysis before propensity score matching showed that the TT group had a 31% reduction in cause-specific survival relative to the PC group (HR: 0.69, 95% CI: 0.61-0.78, p < 0.001) and a 28% reduction in OS (HR: 0.72, 95% CI: 0.66-0.79, p < 0.001). After propensity score matching, the 2 groups yielded 972 patients, with 3-year cause-specific survival rates of 54.1% and 68.5% in the TT group and the PC group, respectively. CONCLUSIONS: Patients who underwent PC had a better prognosis than those who received TT. In addition, for MIBC patients who required bladder-sparing therapy, advanced age (≥80 years), pathological type of squamous cell carcinoma, and tumor stage of T3-4, N2-3, and M1 were independent poor prognostic factors.

Deregulated bile acids may drive hepatocellular carcinoma metastasis by inducing an immunosuppressive microenvironment.

Bile acids (BAs) are physiological detergents that can not only promote the digestion and absorption of lipids, but also may be a potential carcinogen. The accumulation of BAs in the body can lead to cholestatic liver cirrhosis and even liver cancer. Recently, studies demonstrated that BAs are highly accumulated in metastatic lymph nodes, but not in normal healthy lymph nodes or primary tumors. Lymph node metastasis is second only to hematogenous metastasis in liver cancer metastasis, and the survival and prognosis of hepatocellular carcinoma (HCC) patients with lymph node metastasis are significantly worse than those without lymph node metastasis. Meanwhile, component of BAs was found to significantly enhance the invasive potential of HCC cells. However, it is still poorly understood how deregulated BAs fuel the metastasis process of liver cancer. The tumor microenvironment is a complex cellular ecosystem that evolves with and supports tumor cells during their malignant transformation and metastasis progression. Aberrant BAs metabolism were found to modulate tumor immune microenvironment by preventing natural killer T (NKT) cells recruitment and increasing M2-like tumor-associated macrophages (TAMs) polarization, thus facilitate tumor immune escape and HCC development. Based on these available evidence, we hypothesize that a combination of genetic and epigenetic factors in cancerous liver tissue inhibits the uptake and stimulates the synthesis of BAs by the liver, and excess BAs further promote liver carcinogenesis and HCC metastasis by inducing immunosuppressive microenvironment.

Unexpected detection of a submillimeter early hepatocellular carcinoma focus by intraoperative near-infrared fluorescence imaging-a case report.

Background: Prognosis of hepatocellular carcinoma (HCC) is closely related to residual tumor cells and tissues after tumor resection. Thus, close monitoring to ensure complete removal of residual tumor is fundamental. In this regard, intraoperative near-infrared fluorescence (NIRF) imaging has been of great assistance to surgeons for precision cancer surgeries. However, up to now, the identification of tiny lesions has not been reported. Herein, we report our findings on the case of an ultra-small HCC focus of about 430 µm that was successfully detected using NIRF during real-time monitored liver cancer surgery. The patient had a background of hepatitis B cirrhosis, which is the most phenomenon in China. Surgeons usually unable to distinguish sclerotic nodules from small tumor tissue with the naked eyes. Case Description: A 55-year-old man with chronic hepatitis B infection was preoperatively diagnosed with a space-occupying liver lesion. A fluorescence signal was detected on the surface of the liver through the NIRF imaging system which had not been found by preoperative computed tomography (CT) and ultrasound examination. We subsequently tested the residual liver surface and observed a high signal point, less than 1 mm in the right anterior lobe of the liver. Histopathological examination revealed that the tiny fluorescent spot belong to an early HCC focus. Conclusions: Based on these results, we think indocyanine green (ICG)-NIRF imaging may be used as a routine intraoperative detection method for liver cancer surgery in order to remove any residual tumor cells and tissue, hence minimizing further risk of remnant tumor regrowth.

Genome-wide methylation profiling of early colorectal cancer using an Illumina Infinium Methylation EPIC BeadChip.

BACKGROUND: DNA methylation is a part of epigenetic modification, that is closely related to the growth and development of colorectal cancer (CRC). Specific methylated genes and methylated diagnostic models of tumors have become current research focuses. The methylation status of circulating DNA in plasma might serve as a potential biomarker for CRC. AIM: To investigate genome-wide methylation pattern in early CRC using the Illumina Infinium Human Methylation 850K BeadChip. METHODS: The 850K Methylation BeadChip was used to analyze the genome-wide methylation status of early CRC patients (n = 5) and colorectal adenoma patients (n = 5). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enrichment analyses were performed on the selected differentially methylated sites to further discover candidate methylation biomarkers in plasma. RESULTS: A total of 1865 methylated CpG sites with significant differences were detected, including 676 hypermethylated sites and 1189 hypomethylated sites. The distribution of these sites covered from the 1st to 22nd chromosomes and are mainly distributed on the gene body and gene promoter region. GO and KEGG enrichment analysis showed that the functions of these genes were related to biological regulation, molecular binding, transcription factor activity and signal transduction pathway. CONCLUSION: The study demonstrated that the Illumina Infinium Human Methylation 850K BeadChip can be used to investigate genome-wide methylation status of plasma DNA in early CRC and colorectal adenoma patients.

circ3323 Motivates Host Gene to Promote the Aggressiveness of Bladder Cancer.

Bladder cancer (BCa) is the most common cancer in the urinary system with high recurrence rate and poor prognosis. Circular RNA (circRNA) is a novel subclass of noncoding-RNA which participate in progression of BCa. Here, we identified a novel circRNA-circ3323 and aimed to investigate the role of circ3323 in progression of BCa. Public data of RNA sequencing was used to identify significant circRNA related to BCa. The role of circRNAs in progression of BCa was assessed in cytotoxicity assay, transwell assay and flow cytometry. Biotin-coupled RNA pull-down and fluorescence in situ hybridization were performed to evaluate the interaction between circRNAs and miRNAs. The expression of circ3323 was higher in BCa tissues and cells than in normal samples. Experiments in vitro showed that the knockdown of circ3323 inhibited cell proliferation and impeded the metastasis of BCa cells. Mechanistically, we demonstrated that circ3323 acts as a sponge for miR-186-5p and promotes host gene APP's expression. Clinically, circ3323 predicts worse overall survival of BCa patients, indicating its prognostic value. Our study identified that circ3323 modulates metastasis of BCa through miR-186-5p/APP axis and may serve as a promising prognostic biomarker for BCa, which provides novel insights into treatment of BCa.

Integrative analysis the characterization of peroxiredoxins in pan-cancer.

BACKGROUND: Peroxiredoxins (PRDXs) are an antioxidant enzymes protein family involved in several biological functions such as differentiation, cell growth. In addition, previous studies report that PRDXs play critical roles in the occurrence and development of carcinomas. However, few studies have conducted systematic analysis of PRDXs in cancers. Therefore, the present study sought to explore the molecular characteristics and potential clinical significance of PRDX family members in pan cancer and further validate the function of PRDX6 in bladder urothelial carcinoma (BLCA). METHODS: A comprehensive analysis of PRDXs in 33 types of cancer was performed based on the TCGA database. This involved an analysis of mRNA expression profiles, genetic alterations, methylation, prognostic values, potential biological pathways and target drugs. Moreover, both the gain and loss of function strategies were used to assess the importance and mechanism of PRDX6 in the cell cycle of BLCA. RESULT: Analysis showed abnormal expression of PRDX1-6 in several types of cancer compared to normal tissues. Univariate Cox proportional hazard regression analysis showed that expression levels of PRDX1, PRDX4 and PRDX6 were mostly associated with poor survival of OS, DSS and PFI, and PRDX2 and PRDX3 with favorable survival. In addition, the expression of PRDX genes were positively correlated with CNV and negatively with methylation. Moreover, analysis based on PharmacoDB dataset showed that the augmented levels of PRDX1, PRDX3 and PRDX6 were significantly correlated with EGFR/VEGFR inhibitor drugs. Furthermore, knocking down of PRDX6 inhibited growth of cancer cells through the JAK2-STAT3 in bladder cell lines. CONCLUSIONS: PRDXs are potential biomarkers and therapeutic targets for several carcinomas, especially for BLCA. In addition, PRDX6 could regulate proliferation of cancer cell via JAK2-STAT3 pathway and involve into the process of cell cycle in BLCA.

Inhibition of mTOR signaling and clinical activity of metformin in oral premalignant lesions.

BACKGROUNDThe aberrant activation of the PI3K/mTOR signaling circuitry is one of the most frequently dysregulated signaling events in head and neck squamous cell carcinoma (HNSCC). Here, we conducted a single-arm, open-label phase IIa clinical trial in individuals with oral premalignant lesions (OPLs) to explore the potential of metformin to target PI3K/mTOR signaling for HNSCC prevention.METHODSIndividuals with OPLs, but who were otherwise healthy and without diabetes, underwent pretreatment and posttreatment clinical exam and biopsy. Participants received metformin for 12 weeks (week 1, 500 mg; week 2, 1000 mg; weeks 3-12, 2000 mg daily). Pretreatment and posttreatment biopsies, saliva, and blood were obtained for biomarker analysis, including IHC assessment of mTOR signaling and exome sequencing.RESULTSTwenty-three participants were evaluable for response. The clinical response rate (defined as a ≥50% reduction in lesion size) was 17%. Although lower than the proposed threshold for favorable clinical response, the histological response rate (improvement in histological grade) was 60%, including 17% complete responses and 43% partial responses. Logistic regression analysis revealed that when compared with never smokers, current and former smokers had statistically significantly increased histological responses (P = 0.016). Remarkably, a significant correlation existed between decreased mTOR activity (pS6 IHC staining) in the basal epithelial layers of OPLs and the histological (P = 0.04) and clinical (P = 0.01) responses.CONCLUSIONTo our knowledge this is the first phase II trial of metformin in individuals with OPLs, providing evidence that metformin administration results in encouraging histological responses and mTOR pathway modulation, thus supporting its further investigation as a chemopreventive agent.TRIAL REGISTRATIONNCT02581137FUNDINGNIH contract HHSN261201200031I, grants R01DE026644 and R01DE026870.

Clinical effect of Brisson operation modified by Y-shaped incision for treatment of concealed penis in adolescents.

OBJECTIVE: To analyze the clinical effect of the Brisson operation modified by a Y-shaped incision in treating adolescent concealed penis. METHODS: We retrospectively analyzed clinical data of 27 adolescents with a concealed penis treated with the Brisson operation modified by a Y-shaped incision in our hospital from January 2017 to March 2020. RESULTS: The operation went smoothly in all 27 patients. Postoperative foreskin edema occurred in 12 patients and spontaneously resolved within 1 month postoperatively. Two patients developed postoperative retropubic infection. After administering antibiotics and symptomatic treatment, both patients' conditions improved within 1 week. All operations obtained satisfactory results. Postoperatively, when the penis was in a non-erect state, it was clearly exposed without retraction or concealment; thus, demonstrating good surgical results. The prepuce was distributed naturally without obvious accumulation of redundant preputial tissue. The penile scar resembled that after circumcision. The postoperative follow-up period was 6 months, during which no patients developed recurrence. CONCLUSION: The Brisson operation modified by a Y-shaped incision is effective for treating a concealed penis in adolescent patients. This technique may relieve the pathological abnormalities and retain the penile skin's integrity to the greatest extent with minimal scarring and a satisfactory appearance.

Synthetic Lethal Screens Reveal Cotargeting FAK and MEK as a Multimodal Precision Therapy for GNAQ-Driven Uveal Melanoma.

PURPOSE: Uveal melanoma is the most common eye cancer in adults. Approximately 50% of patients with uveal melanoma develop metastatic uveal melanoma (mUM) in the liver, even after successful treatment of the primary lesions. mUM is refractory to current chemo- and immune-therapies, and most mUM patients die within a year. Uveal melanoma is characterized by gain-of-function mutations in GNAQ/GNA11, encoding Gαq proteins. We have recently shown that the Gαq-oncogenic signaling circuitry involves a noncanonical pathway distinct from the classical activation of PLCß and MEK-ERK. GNAQ promotes the activation of YAP1, a key oncogenic driver, through focal adhesion kinase (FAK), thereby identifying FAK as a druggable signaling hub downstream from GNAQ. However, targeted therapies often activate compensatory resistance mechanisms leading to cancer relapse and treatment failure. EXPERIMENTAL DESIGN: We performed a kinome-wide CRISPR-Cas9 sgRNA screen to identify synthetic lethal gene interactions that can be exploited therapeutically. Candidate adaptive resistance mechanisms were investigated by cotargeting strategies in uveal melanoma and mUM in vitro and in vivo experimental systems. RESULTS: sgRNAs targeting the PKC and MEK-ERK signaling pathways were significantly depleted after FAK inhibition, with ERK activation representing a predominant resistance mechanism. Pharmacologic inhibition of MEK and FAK showed remarkable synergistic growth-inhibitory effects in uveal melanoma cells and exerted cytotoxic effects, leading to tumor collapse in uveal melanoma xenograft and liver mUM models in vivo. CONCLUSIONS: Coupling the unique genetic landscape of uveal melanoma with the power of unbiased genetic screens, our studies reveal that FAK and MEK-ERK cotargeting may provide a new network-based precision therapeutic strategy for mUM treatment.See related commentary by Harbour, p. 2967.

The oncogenic role of MUC12 in RCC progression depends on c-Jun/TGF-ß signalling.

Renal cell carcinoma (RCC) is a common kidney cancer worldwide. Even though current treatments show promising therapeutic effectiveness, metastatic RCC still has limited therapeutic options so that novel treatments were urgently needed. Here, we identified that MUC12 was overexpressed in RCC patients and served as poor prognostic factor for RCC progression. Overexpression of MUC12 increased RCC cell growth and cell invasion while deficiency of MUC12 exerted opposite effects on RCC cells. Mechanistic dissection demonstrated that MUC12-mediated RCC cell growth and cell invasion were dependent of TGF-ß1 signalling because they could be blocked in the presence of TGF-ß1 inhibitor. Moreover, the regulation of TGF-ß1 by MUC12 relied on the transactivation of c-Jun. MUC12 promoted the recruitment of c-Jun on the promoter of TGF-ß1, leading to its transcription. Importantly, knockdown of c-Jun also attenuated MUC12-mediated TGF-ß1 induction and RCC cell invasion. In summary, our study defines the role of MUC12 in RCC progression and provides rational to develop novel targeted therapy to battle against RCC.

Pathway-Specific Genome Editing of PI3K/mTOR Tumor Suppressor Genes Reveals that PTEN Loss Contributes to Cetuximab Resistance in Head and Neck Cancer.

Cetuximab, an mAb targeting EGFR, is a standard of care for the treatment for locally advanced or metastatic head and neck squamous cell carcinoma (HNSCC). However, despite overexpression of EGFR in more than 90% of HNSCC lesions, most patients with HNSCC fail to respond to cetuximab treatment. In addition, there are no available biomarkers to predict sensitivity or resistance to cetuximab in the clinic. Here, we sought to advance precision medicine approaches for HNSCC by identifying PI3K/mTOR signaling network-specific cetuximab resistance mechanisms. We first analyzed the frequency of genomic alterations in genes involved in the PI3K/mTOR signaling circuitry in the HNSCC TCGA dataset. Experimentally, we took advantage of CRISPR/Cas9 genome editing approaches to systematically explore the contribution of genomic alterations in each tumor suppressor gene (TSG) controlling the PI3K-mTOR pathway to cetuximab resistance in HNSCC cases that do not exhibit PIK3CA mutations. Remarkably, we found that many HNSCC cases exhibit pathway-specific gene copy number loss of multiple TSGs that normally restrain PI3K/mTOR signaling. Among them, we found that both engineered and endogenous PTEN gene deletions can mediate resistance to cetuximab. Our findings suggest that PTEN gene copy number loss, which is highly prevalent in HNSCC, may result in sustained PI3K/mTOR signaling independent of EGFR, thereby representing a promising mechanistic biomarker predictive of cetuximab resistance in this cancer type. Further prospective studies are needed to investigate the impact of PTEN loss on cetuximab efficacy in the clinic.

Targeted antitumor activity of Ginsenoside (Rg1) in paclitaxel-resistant human nasopharyngeal cancer cells are mediated through activation of autophagic cell death, cell apoptosis, endogenous ROS production, S phase cell cycle arrest and inhibition of m-TOR/PI3K/AKT signalling pathway.

PURPOSE: Nasopharyngeal carcinoma is one of common and vicious cancers of head and neck. The main purpose of this study was to examine the anticancer effects of the naturally occurring compound Ginsenoside (Rg1) against paclitaxel-resistant human nasopharyngeal cancer cells along with evaluation of its effects on cell autophagy, apoptosis, ROS production, cell cycle progression and m-TOR/PI3K/AKT signalling pathway. METHODS: The viability of SUNE1 cancer cell line and NP460 normal cell line was checked by CCK8 counting assay. Apoptosis-related studies were examined by fluorescent microscopy using acridine orange (AO)/ethidium bromide (EB) staining as well as flow cytometry using annexin V assay. Further, transmission electron microscopy (TEM) was used to study autophagic effects induced by Ginsenoside (Rg1). Western blot assay was used to study the effects of Ginsenoside on apoptosis and on autophagy-related protein expressions including Bax, Bcl-2, LC3-ll. RESULTS: The results indicated that Ginsenoside (Rg1) reduces the viability of the nasopharyngeal carcinoma cells in a dose-dependent manner, showing IC50 of 15 µM in cancer cells and IC50 of 80 µM in normal cell lines. The AO/EB staining showed that Ginsenoside (Rg1) inhibits the viability of cancer cells via induction of apoptotic cell death which was correlated with increase in Bax and decrease in Bcl-2 levels. Electron microscopic analysis showed that Ginsenoside (Rg1) caused the development of autophagosomes in cancer cells. Similarly, Ginsenoside (Rg1) increased the expression of LC3-II protein, indicating autophagic cell death. Ginsenoside (Rg1) also induced dose-dependent S phase cell cycle arrest. Western blot analysis showed that Ginsenoside (Rg1) has the potential to block m-TOR/PI3K/AKT signalling pathway. CONCLUSIONS: In conclusion, the results of this study clearly indicate that Ginsenoside (Rg1) could be developed as a potent candidate drug against nasopharyngeal cancer provided further in vivo studies as well as toxicological studies are carried out.

CDKN1B Val 109 Gly variant is not related to risk of prostate cancer.

Association between CDKN1B gene Val 109 Gly polymorphism and prostate cancer (PCa) susceptibility has been investigated in several studies but with inconsistent conclusions. We adopted odds ratios (ORs) and 95% confidence intervals (CIs) to assess the correlation between CDKN1B Val 109 Gly variant and PCa susceptibility. Moreover, we used in-silico tools to evaluate the relationship of CDKN1B expression and overall survival (OS) or disease free survival (DFS) time in PCa patients. The overall results demonstrated no association of the CDKN1B variant on PCa risk [allelic contrast (OR = 0.78, 95% CI = 0.45 - 1.35, Pheterogeneity = 0.038); GV vs VV (OR = 0.83, 95% CI = 0.56 - 1.25, Pheterogeneity = 0.253); GG vs VV (OR = 0.48, 95% CI = 0.23 - 1.01, Pheterogeneity = 0.161); GG+GV vs VV (OR = 0.75, 95% CI = 0.52 -1.08, Pheterogeneity = 0.132) and GG vs GV+VV (OR = 0.63, 95% CI = 0.25 - 1.11, Pheterogeneity = 0.152)]. In subgroup analysis by ethnicity and source of control, we also identified similar results. In-silico results showed that expression of CDKN1B was decreased in PCa tissue, especially in less advanced PCa (Gleason score = 6 or 7). No significant difference of OS or DFS time was indicated between the low and high expression of CDKN1B. Our present study showed evidence that CDKN1B Val 109 Gly variant is not related to PCa risk. Future studies with large sample size are needed to confirm this correlation in more details.