IL-1ß-associated NNT acetylation orchestrates iron-sulfur cluster maintenance and cancer immunotherapy resistance.

Interleukin-1ß (IL-1ß) is a key protein in inflammation and contributes to tumor progression. However, the role of IL-1ß in cancer is ambiguous or even contradictory. Here, we found that upon IL-1ß stimulation, nicotinamide nucleotide transhydrogenase (NNT) in cancer cells is acetylated at lysine (K) 1042 (NNT K1042ac) and thereby induces the mitochondrial translocation of p300/CBP-associated factor (PCAF). This acetylation enhances NNT activity by increasing the binding affinity of NNT for NADP+ and therefore boosts NADPH production, which subsequently sustains sufficient iron-sulfur cluster maintenance and protects tumor cells from ferroptosis. Abrogating NNT K1042ac dramatically attenuates IL-1ß-promoted tumor immune evasion and synergizes with PD-1 blockade. In addition, NNT K1042ac is associated with IL-1ß expression and the prognosis of human gastric cancer. Our findings demonstrate a mechanism of IL-1ß-promoted tumor immune evasion, implicating the therapeutic potential of disrupting the link between IL-1ß and tumor cells by inhibiting NNT acetylation.

Performance of common genetic variants in risk prediction for colorectal cancer in Chinese: A two-stage and multicenter study.

The efficacy of susceptible variants derived from genome-wide association studies (GWAs) optimizing discriminatory accuracy of colorectal cancer (CRC) in Chinese remains unclear. In the present validation study, we assessed 75 recently identified variants from GWAs. A risk predictive model combining 19 variants using the least absolute shrinkage and selection operator (LASSO) statistics offered certain clinical advantages. This model demonstrated an area under the receiver operating characteristic (AUC) of 0.61 during training analysis and yielded robust AUCs from 0.59 to 0.61 during validation analysis in three independent centers. The individuals carrying the highest quartile of risk score revealed over 2-fold risks of CRC (ranging from 2.12 to 2.90) compared with those who presented the lowest quartile of risk score. This genetic model offered the possibility of partitioning risk within the average risk population, which might serve as a first step toward developing individualized CRC prevention strategies in China.

EPHA7 mutation as a predictive biomarker for immune checkpoint inhibitors in multiple cancers.

BACKGROUND: A critical and challenging process in immunotherapy is to identify cancer patients who could benefit from immune checkpoint inhibitors (ICIs). Exploration of predictive biomarkers could help to maximize the clinical benefits. Eph receptors have been shown to play essential roles in tumor immunity. However, the association between EPH gene mutation and ICI response is lacking. METHODS: Clinical data and whole-exome sequencing (WES) data from published studies were collected and consolidated as a discovery cohort to analyze the association between EPH gene mutation and efficacy of ICI therapy. Another independent cohort from Memorial Sloan Kettering Cancer Center (MSKCC) was adopted to validate our findings. The Cancer Genome Atlas (TCGA) cohort was used to perform anti-tumor immunity and pathway enrichment analysis. RESULTS: Among fourteen EPH genes, EPHA7-mutant (EPHA7-MUT) was enriched in patients responding to ICI therapy (FDR adjusted P < 0.05). In the discovery cohort (n = 386), significant differences were detected between EPHA7-MUT and EPHA7-wildtype (EPHA7-WT) patients regarding objective response rate (ORR, 52.6% vs 29.1%, FDR adjusted P = 0.0357) and durable clinical benefit (DCB, 70.3% vs 42.7%, FDR adjusted P = 0.0200). In the validation cohort (n = 1144), significant overall survival advantage was observed in EPHA7-MUT patients (HR = 0.62 [95% confidence interval, 0.39 to 0.97], multivariable adjusted P = 0.0367), which was independent of tumor mutational burden (TMB) and copy number alteration (CNA). Notably, EPHA7-MUT patients without ICI therapy had significantly worse overall survival in TCGA cohort (HR = 1.33 [95% confidence interval, 1.06 to 1.67], multivariable adjusted P = 0.0139). Further gene set enrichment analysis revealed enhanced anti-tumor immunity in EPHA7-MUT tumor. CONCLUSIONS: EPHA7-MUT successfully predicted better clinical outcomes in ICI-treated patients across multiple cancer types, indicating that EPHA7-MUT could serve as a potential predictive biomarker for immune checkpoint inhibitors.

Liquid biopsies to track trastuzumab resistance in metastatic HER2-positive gastric cancer.

OBJECTIVE: To monitor trastuzumab resistance and determine the underlying mechanisms for the limited response rate and rapid emergence of resistance of HER2+ metastatic gastric cancer (mGC). DESIGN: Targeted sequencing of 416 clinically relevant genes was performed in 78 paired plasma and tissue biopsy samples to determine plasma-tissue concordance. Then, we performed longitudinal analyses of 97 serial plasma samples collected from 24 patients who were HER2+ to track the resistance during trastuzumab treatment and validated the identified candidate resistance genes. RESULTS: The results from targeted sequencing-based detection of somatic copy number alterations (SCNA) of HER2 gene were highly consistent with fluorescence in situ hybridisation data, and the detected HER2 SCNA was better than plasma carcinoembryonic antigen levels at predicting tumour shrinkage and progression. Furthermore, most patients with innate trastuzumab resistance presented high HER2 SCNA during progression compared with baseline, while HER2 SCNA decreased in patients with acquired resistance. PIK3CA mutations were significantly enriched in patients with innate resistance, and ERBB2/4 genes were the most mutated genes, accounting for trastuzumab resistance in six (35.3%) and five (29.4%) patients in baseline and progression plasma, respectively. Patients with PIK3CA/R1/C3 or ERBB2/4 mutations in the baseline plasma had significantly worse progression-free survival. Additionally, mutations in NF1 contributed to trastuzumab resistance, which was further confirmed through in vitro and in vivo studies, while combined HER2 and MEK/ERK blockade overcame trastuzumab resistance. CONCLUSION: Longitudinal circulating tumour DNA sequencing provides novel insights into gene alterations underlying trastuzumab resistance in HER2+mGC.

METTL3 facilitates tumor progression via an m6A-IGF2BP2-dependent mechanism in colorectal carcinoma.

BACKGROUND: Colorectal carcinoma (CRC) is one of the most common malignant tumors, and its main cause of death is tumor metastasis. RNA N6-methyladenosine (m6A) is an emerging regulatory mechanism for gene expression and methyltransferase-like 3 (METTL3) participates in tumor progression in several cancer types. However, its role in CRC remains unexplored. METHODS: Western blot, quantitative real-time PCR (RT-qPCR) and immunohistochemical (IHC) were used to detect METTL3 expression in cell lines and patient tissues. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptomic RNA sequencing (RNA-seq) were used to screen the target genes of METTL3. The biological functions of METTL3 were investigated in vitro and in vivo. RNA pull-down and RNA immunoprecipitation assays were conducted to explore the specific binding of target genes. RNA stability assay was used to detect the half-lives of the downstream genes of METTL3. RESULTS: Using TCGA database, higher METTL3 expression was found in CRC metastatic tissues and was associated with a poor prognosis. MeRIP-seq revealed that SRY (sex determining region Y)-box 2 (SOX2) was the downstream gene of METTL3. METTL3 knockdown in CRC cells drastically inhibited cell self-renewal, stem cell frequency and migration in vitro and suppressed CRC tumorigenesis and metastasis in both cell-based models and PDX models. Mechanistically, methylated SOX2 transcripts, specifically the coding sequence (CDS) regions, were subsequently recognized by the specific m6A "reader", insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2), to prevent SOX2 mRNA degradation. Further, SOX2 expression positively correlated with METTL3 and IGF2BP2 in CRC tissues. The combined IHC panel, including "writer", "reader", and "target", exhibited a better prognostic value for CRC patients than any of these components individually. CONCLUSIONS: Overall, our study revealed that METTL3, acting as an oncogene, maintained SOX2 expression through an m6A-IGF2BP2-dependent mechanism in CRC cells, and indicated a potential biomarker panel for prognostic prediction in CRC.

LncRNA LINRIS stabilizes IGF2BP2 and promotes the aerobic glycolysis in colorectal cancer.

BACKGROUND: Long noncoding RNAs (lncRNAs) play nonnegligible roles in the epigenetic regulation of cancer cells. This study aimed to identify a specific lncRNA that promotes the colorectal cancer (CRC) progression and could be a potential therapeutic target. METHODS: We screened highly expressed lncRNAs in human CRC samples compared with their matched adjacent normal tissues. The proteins that interact with LINRIS (Long Intergenic Noncoding RNA for IGF2BP2 Stability) were confirmed by RNA pull-down and RNA immunoprecipitation (RIP) assays. The proliferation and metabolic alteration of CRC cells with LINRIS inhibited were tested in vitro and in vivo. RESULTS: LINRIS was upregulated in CRC tissues from patients with poor overall survival (OS), and LINRIS inhibition led to the impaired CRC cell line growth. Moreover, knockdown of LINRIS resulted in a decreased level of insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), a newly found N6-methyladenosine (m6A) 'reader'. LINRIS blocked K139 ubiquitination of IGF2BP2, maintaining its stability. This process prevented the degradation of IGF2BP2 through the autophagy-lysosome pathway (ALP). Therefore, knockdown of LINRIS attenuated the downstream effects of IGF2BP2, especially MYC-mediated glycolysis in CRC cells. In addition, the transcription of LINRIS could be inhibited by GATA3 in CRC cells. In vivo experiments showed that the inhibition of LINRIS suppressed the proliferation of tumors in orthotopic models and in patient-derived xenograft (PDX) models. CONCLUSION: LINRIS is an independent prognostic biomarker for CRC. The LINRIS-IGF2BP2-MYC axis promotes the progression of CRC and is a promising therapeutic target.

Phase II clinical trial of S-1 plus nanoparticle albumin-bound paclitaxel in untreated patients with metastatic gastric cancer.

The present study is the first phase II clinical trial aimed to evaluate the efficacy and safety of S-1 plus nanoparticle albumin-bound paclitaxel (Nab-PTX) as first-line chemotherapy for advanced gastric cancer (AGC). Previously untreated patients with metastatic gastric adenocarcinoma received S-1 in oral doses of 40 mg (BSA <1.25 m2 ), 50 mg (1.25 ≤ BSA < 1.50 m2 ) and 60 mg (BSA ≥1.50 m2 ) b.i.d. on days 1-14 in combination with Nab-PTX (120 mg/m2 , on days 1 and 8) for each 21-day cycle. Primary endpoint was progression-free survival (PFS), and secondary endpoints were overall response rate (ORR), overall survival (OS), disease control rate (DCR), and toxicity. A total of 73 gastric cancer patients with metastatic and measurable lesions were enrolled in the first-line setting. Median PFS and OS were 9.63 months and 14.60 months, respectively. Four (5.5%) patients had complete responses, 39 (53.4%) had partial responses (PRs), 21 (28.8%) had stable disease, four (5.5%) progressed and five (6.8%) were not evaluable. ORR and DCR were 58.9% and 87.7%, respectively. Most toxicities were mild, and no treatment-related deaths occurred. Grade 3 to 4 toxicities occurred in 22 patients (30.1%) as follows: leukopenia (13.7%), neutropenia (12.3%), anemia (5.5%), thrombocytopenia (1.4%), diarrhea (6.8%), vomiting (2.7%), stomatitis (1.4%), peripheral neuropathy (1.4%), and hand-foot syndrome (1.4%). Seven patients achieved good responses and underwent gastrectomy plus metastasectomy. Thirty (41.1%) patients had S-1 maintenance with a median of four cycles. S-1 plus Nab-PTX is an efficient and safe regimen as first-line treatment for patients with AGC.

Hepatitis B virus infection is associated with younger median age at diagnosis and death in cancers.

Several non-hepatocellular cancers were linked with hepatitis B virus (HBV) infection. This study was aimed to quantify the potential associations between HBV infection and multiple non-hepatocellular cancers. Continuous cases, including 5,715 non-cancer and 40,963 cancer cases diagnosed from 2008 to 2014 in Sun Yat-sen University Cancer Center were analyzed. HBV DNA and hepatitis B core antigen (HBcAg) were examed in gastric cancer tissues by polymerase chain reaction and immunohistochemical staining. After adjusting for age, sex, year of diagnosis, smoking, drinking and family history of cancer, significant associations were found between serum HBsAg and frequently reported HBV-related non-hepatocellular cancers, including non-Hodgkin's lymphoma, cholangiocarcinoma and pancreatic cancer [adjusted odds ratio (AOR) and 95% confidence interval (CI): 1.89 (1.65-2.16)], as well as total other non-hepatocellular cancers [AOR and 95% CI: 1.12 (1.03-1.22)]. The median ages at diagnosis, all-cause death and cancer-specific death of serum HBsAg positive cancer patients were all significantly younger than those with serum HBsAg negative. HBV DNA was detected in 12.4% (34/275) gastric cancer tissues and HBcAg was most commonly detected in lymphocytes. This was the first report that HBV infection had a modest but significant nonspecific association with total non-hepatocellular cancers. Median age at diagnosis and death was significantly younger in serum HBsAg positive cancer patients. The underlying mechanism needs further investigation.

Increased expression of EIF5A2, via hypoxia or gene amplification, contributes to metastasis and angiogenesis of esophageal squamous cell carcinoma.

BACKGROUND & AIMS: Solid tumors often become hypoxic, leading to activation of hypoxia-response genes. We investigated the effects of overexpression of the hypoxia response genes eIF5A2 in esophageal squamous cell carcinoma (ESCC). METHODS: We used quantitative real-time polymerase chain reaction and immunohistochemistry analyses to compare expression of eIF5A2 between paired ESCC samples and nontumor esophageal tissues, and fluorescence in situ hybridization to detect gene copy-number alterations. Luciferase reporter and chromatin immunoprecipitation assays were used to study interactions between eIF5A2 and hypoxia-inducible factor-1α (HIF1α). We determined the effects of eIF5A2 overexpression and knockdown in ESCC cell lines and growth of ESCC xenograft tumors in nude mice. RESULTS: Levels of eIF5A2 messenger RNA and protein were increased in >40% of ESCC samples compared with matched nontumor tissues, along with levels of HIF1α and vascular endothelial growth factor. Increased levels of EIF5A2 were significantly associated with ESCC metastasis to lymph nodes (P < .001) and tissue invasion (P = .037), and shorter survival times of patients (P < .001). Amplification of eIF5A2 was detected in 35.14% of ESCC samples that overexpressed eIF5A2. Hypoxia increased expression of eIF5A2 4- to 8-fold in ESCC cell lines; we observed bidirectional regulation between eIF5A2 and HIF1α. Transient transfection of ESCC cell lines with eIF5A2 increased their migratory and invasive abilities and markers of the epithelial to mesenchymal transition, and eIF5A2 knockdown or HIFα inhibition reduced these. In mice, xenograft tumors grown from ESCC cells that expressed eIF5A2 formed tumors more rapidly than cells that expressed only vector (controls); they also expressed higher levels of HIF1α and vascular endothelial growth factor, and formed more microvessels than controls. Knockdown of eIF5A2 in ESCC cells with interfering RNAs reduced their growth as xenograft tumors in mice, particularly when mice were given docetaxel or cisplatin. CONCLUSIONS: eIF5A2 is overexpressed by gene amplification or hypoxia in ESCCs, and associated with up-regulation of HIF1α, metastasis, and shorter survival times of patients. Increased expression of eIF5A2 increases metastasis and angiogenesis in ESCC via the HIF1α-mediated signaling pathway.

Identification of microRNA-214 as a negative regulator of colorectal cancer liver metastasis by way of regulation of fibroblast growth factor receptor 1 expression.

UNLABELLED: The purpose of this study was to identify microRNAs (miRNAs) involved in the pathology of colorectal cancer (CRC) liver metastasis and investigate their underlying mechanisms. A total of 39 miRNAs were identified to be differentially expressed between 16 primary CRC tissues with liver metastases and 16 CRC tissues without liver metastases from 32 patients by Affymetric miRNA microarrays. A panel of eight miRNAs were confirmed to be significantly and differentially expressed between CRC tissues with and without liver metastases through quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis in the 32 patients. In a validated cohort of 99 CRC patients (44 with and 55 without liver metastases), only miR-214 was validated to be significantly down-regulated in CRC with liver metastases, which was associated with an unfavorable prognosis. Ectopic expression of miR-214 suppressed proliferation, migration, and invasion in vitro, tumor growth and liver metastasis in an in vivo xenograft mouse model, whereas miR-214 knockdown promoted proliferation, migration, and invasion in CRC cell lines. Further studies indicated that fibroblast growth factor receptor 1 (FGFR1) was a potential target of miR-214. Restoring miR-214 expression in CRC cells decreased endogenous FGFR1 messenger RNA (mRNA) and protein levels. FGFR1 knockdown mimicked the tumor suppressive effect of miR-214 on CRC cells, while reintroduction of FGFR1 abolished the tumor suppressive effect of miR-214 on CRC cells. Moreover, miR-214 expression levels were inversely correlated with FGFR1 in CRC patients. CONCLUSION: Down-regulation of miR-214 expression was correlated with increased FGFR1 expression levels, which may contribute to increased CRC liver metastasis. miR-214 may serve as a potential marker to predict survival, and the miR-214-FGFR1 axis may be a therapeutic target in CRC patients.

Reduced expression of p21-activated protein kinase 1 correlates with poor histological differentiation in pancreatic cancer.

BACKGROUND: P21-activated protein kinase 1 (PAK1), a main downstream effector of small Rho GTPases, is overexpressed in many malignancies. PAK1 overexpression is associated with poor prognosis in some tumor types, including breast cancer, gastric cancer, and colorectal cancer. However, the expression and clinical relevance of PAK1 expression in human pancreatic cancer remains unknown. METHODS: The present study investigated the clinical and prognostic significance of PAK1 expression in pancreatic carcinoma. We examined and scored the expression of PAK1 by immunohistochemistry in 72 primary pancreatic carcinoma samples and 20 liver metastatic samples. The relationships between PAK1 and clinicopathological parameters and prognosis in primary and metastatic pancreatic cancer were analyzed. RESULTS: Among the total 92 cases, primary pancreatic cancer samples had a significantly higher rate (38/72, 52.8%) of high PAK1 expression than liver metastatic samples (5/20, 25.0%) (P=0.028). Among the 72 primary pancreatic cancer patients, high PAK1 expression was associated with younger age (P=0.038) and moderately or well differentiated tumor (P=0.007). Moreover, a positive relationship was found between high PAK1 expression and overall survival (OS) (P<0.005). Patients with high PAK1 expression had a better OS than those with low PAK1 expression. Univariate and multivariate analysis by Cox regression including PAK1 and other prognostic pathological markers demonstrated high PAK1 immunostaining as a prognostic factor for survival in pancreatic cancer patients (P<0.005). CONCLUSIONS: We report for the first time that PAK1 is a novel prognostic marker for pathologically confirmed human pancreatic cancer. Reduced expression of PAK1 correlates with poor histological differentiation in pancreatic cancer.

HIPK3 maintains sensitivity to platinum drugs and prevents disease progression in gastric cancer.

In the realm of cancer therapeutics and resistance, kinases play a crucial role, particularly in gastric cancer (GC). Our study focused on platinum-based chemotherapy resistance in GC, revealing a significant reduction in homeodomain-interacting protein kinase 3 (HIPK3) expression in platinum-resistant tumors through meticulous analysis of transcriptome datasets. In vitro and in vivo experiments demonstrated that HIPK3 knockdown enhanced tumor proliferation and metastasis, while upregulation had the opposite effect. We identified the myocyte enhancer factor 2C (MEF2C) as a transcriptional regulator of HIPK3 and uncovered HIPK3's role in downregulating the morphogenesis regulator microtubule-associated protein (MAP7) through ubiquitination. Phosphoproteome profiling revealed HIPK3's inhibitory effects on mTOR and Wnt pathways crucial in cell proliferation and movement. A combined treatment strategy involving oxaliplatin, rapamycin, and IWR1-1-endo effectively overcame platinum resistance induced by reduced HIPK3 expression. Monitoring HIPK3 levels could serve as a GC malignancy and platinum resistance indicator, with our proposed treatment strategy offering novel avenues for reversing resistance in gastric cancer.

Machine learning-based extrachromosomal DNA identification in large-scale cohorts reveals its clinical implications in cancer.

The clinical implications of extrachromosomal DNA (ecDNA) in cancer therapy remain largely elusive. Here, we present a comprehensive analysis of ecDNA amplification spectra and their association with clinical and molecular features in multiple cohorts comprising over 13,000 pan-cancer patients. Using our developed computational framework, GCAP, and validating it with multifaceted approaches, we reveal a consistent pan-cancer pattern of mutual exclusivity between ecDNA amplification and microsatellite instability (MSI). In addition, we establish the role of ecDNA amplification as a risk factor and refine genomic subtypes in a cohort from 1015 colorectal cancer patients. Importantly, our investigation incorporates data from four clinical trials focused on anti-PD-1 immunotherapy, demonstrating the pivotal role of ecDNA amplification as a biomarker for guiding checkpoint blockade immunotherapy in gastrointestinal cancer. This finding represents clinical evidence linking ecDNA amplification to the effectiveness of immunotherapeutic interventions. Overall, our study provides a proof-of-concept of identifying ecDNA amplification from cancer whole-exome sequencing (WES) data, highlighting the potential of ecDNA amplification as a valuable biomarker for facilitating personalized cancer treatment.

Overexpression of paxillin induced by miR-137 suppression promotes tumor progression and metastasis in colorectal cancer.

The deregulation of paxillin (PXN) has been involved in the progression and metastasis of different malignancies including colorectal cancer (CRC). miR-137 is frequently suppressed in CRC. PXN is predicted to be a direct target of miR-137 in CRC cells. On this basis, we hypothesized that overexpression of PXN induced by suppression of miR-137 may promote tumor progression and metastasis and predicts poor prognosis. We detected the expression of PXN and miR-137 in clinical tumor tissues by immunohistochemical analysis and real-time PCR, positive PXN staining was observed in 198 of the 247 (80.1%) cases, whereas no or weak PXN staining was observed in the adjacent non-cancerous area. Higher level of PXN messenger RNA (mRNA) and lower level of miR-137 was observed in cancer tissues than adjacent non-cancerous tissues. High expression of PXN and low expression of miR-137 was associated with aggressive tumor phenotype and adverse prognosis. Moreover, the expression of PXN was negatively correlated with miR-137 expression. A dual-luciferase reporter gene assay validated that PXN was a direct target of miR-137. The use of miR-137 mimics or inhibitor could decrease or increase PXN mRNA and protein levels in CRC cell lines. Knockdown of PXN or ectopic expression of miR-137 could markedly inhibit cell proliferation, migration and invasion in vitro and repress tumor growth and metastasis in vivo. Taken together, these results demonstrated that overexpression of PXN induced by suppression of miR-137 promotes tumor progression and metastasis and could serve as an independent prognostic indicator in CRC patients.

CDC20 overexpression predicts a poor prognosis for patients with colorectal cancer.

BACKGROUND: The cell division cycle 20 homolog (CDC20) is an essential cofactor of the anaphase-promoting complex (APC/C). CDC20 overexpression has been detected in many types of human cancers; however, its clinical role in colorectal cancer remains unknown. METHODS: Western blotting and immunohistochemistry were used to compare CDC20 expression in adjacent non-cancerous, cancerous and liver metastatic tissues as well as in colon cancer cell lines and normal colon epithelial cell lines. Additionally, the correlation of CDC20 expression with patient clinical parameters and its diagnostic value were statistically analyzed. RESULTS: CDC20 was overexpressed in colon cancer cell lines/primary cancer tissues compared with normal colon epithelial cell lines/adjacent noncancerous tissue samples. Interestingly, CDC20 expression was further increased in metastatic liver tissues. CDC20 protein expression was significantly correlated with clinical stage (P = 0.008), N classification (P = 0.020), M classification (P = 0.013) and pathologic differentiation (P = 0.008). Patients with higher CDC20 expression had a shorter overall survival than those with lower CDC20 expression. Univariate and multivariate analyses indicated that CDC20 expression was an independent prognostic factor (P < 0.001). CONCLUSION: CDC20 may serve as a potential prognostic biomarker of human colorectal cancer.

Abnormal expression of paxillin correlates with tumor progression and poor survival in patients with gastric cancer.

BACKGROUND: Paxillin (PXN) has been found to be aberrantly regulated in various malignancies and involved in tumor growth and invasion. The clinicopathological and prognostic significance of PXN in gastric cancer is still unclear. METHODS: The expression of PXN was determined in paired gastric cancer tissues and adjacent normal tissues by Western blotting and real-time PCR. Immunohistochemistry was performed to detect the expression of PXN in 239 gastric cancer patients. Statistical analysis was applied to investigate the correlation between PXN expression and clinicopathological characteristics and prognosis in patients. Additionally, the effects of PXN on gastric cancer cell proliferation and migration were also evaluated. RESULTS: PXN was up-regulated in gastric cancer tissues and cell lines as compared with adjacent normal tissues and normal gastric epithelial cell line GES-1. Overexpression of PXN was correlated with distant metastasis (P=0.001) and advanced tumor stage (P=0.021) in gastric cancer patients. Patients with high PXN expression tended to have poor prognosis compared with patients with low PXN expression (P<0.001). Multivariate analysis demonstrated that PXN expression was an independent prognostic factor (P=0.020). Moreover, ectopic expression of PXN promotes cell proliferation and migration in AGS cells whereas knockdown of PXN inhibits cell proliferation and migration in SGC7901 cells. CONCLUSIONS: PXN plays an important role in tumor progression and may be used as a potential prognostic indicator in gastric cancer.

Prognostic relevance of BRD7 expression in colorectal carcinoma.

BACKGROUND: BRD7 is a member of bromodomain-containing protein and was found to be a cofactor of P53. Down-regulation of BRD7 has been shown in nasopharyngeal carcinoma cell lines and tissues. However, the clinical role of BRD7 in colorectal cancer remains unknown. MATERIALS AND METHODS: Real-time PCR, Western blotting analysis and immunohistochemistry were employed to examine BRD7 expression in CRC cell lines/tissues compared with normal epithelia cells/adjacent non-tumorous tissues. In addition, statistical analyses were applied to evaluate the diagnostic value and associations of BRD7 expression with clinical parameters of patient samples. RESULTS: BRD7 was down-regulated in colorectal cancer cell lines and cancerous tissues compared with that in normal colon epithelial cells and adjacent noncancerous tissue samples. BRD7 protein expression was positively correlated with clinical stage (P  <  0·001), T classification (P  =  0·001), N classification (P  <  0·001), M classification (P <  0·001) and pathologic differentiation (P =  0·008). Patients with low/none BRD7 expression had shorter overall survival time than those with higher BRD7 expression. Univariate and multivariate analyses indicated BRD7 expression was an independent prognostic factor (P < 0·001). CONCLUSION: BRD7 may serve as a potential prognostic biomarker of human colorectal cancer.

FTO up-regulation induced by MYC suppresses tumour progression in Epstein-Barr virus-associated gastric cancer.

BACKGROUND: Epstein-Barr virus-associated gastric cancer (EBVaGC) is regarded as a distinct molecular subtype of GC, accounting for approximately 9% of all GC cases. Clinically, EBVaGC patients are found to have a significantly lower frequency of lymph node metastasis and better prognosis than uninfected individuals. RNA N6-methyladenosine (m6A) modification has an indispensable role in modulating tumour progression in various cancer types. However, its impact on EBVaGC remains unclear. METHODS: Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and m6A dot blot were conducted to compare the m6A modification levels between EBVaGC and EBV-negative GC (EBVnGC) cells. Western blot, real-time quantitative PCR (RT-qPCR) and immunohistochemistry were applied to explore the underlying mechanism of the reduced m6A modification in EBVaGC. The biological function of fat mass and obesity-associated protein (FTO) was determined in vivo and in vitro. The target genes of FTO were screened by MeRIP-seq, RT-qPCR and Western blot. The m6A binding proteins of target genes were verified by RNA pulldown and RNA immunoprecipitation assays. Chromatin immunoprecipitation and Luciferase report assays were performed to investigate the mechanism how EBV up-regulated FTO expression. RESULTS: M6A demethylase FTO was notably increased in EBVaGC, leading to a reduction in m6A modification, and higher FTO expression was associated with better clinical outcomes. Furthermore, FTO depressed EBVaGC cell metastasis and aggressiveness by reducing the expression of target gene AP-1 transcription factor subunit (FOS). Methylated FOS mRNA was specifically recognized by the m6A 'reader' insulin-like growth factor 2 mRNA binding protein 1/2 (IGF2BP1/2), which enhanced its transcripts stability. Moreover, MYC activated by EBV in EBVaGC elevated FTO expression by binding to a specific region of the FTO promoter. CONCLUSIONS: Mechanistically, our work uncovered a crucial suppressive role of FTO in EBVaGC metastasis and invasiveness via an m6A-FOS-IGF2BP1/2-dependent manner, suggesting a promising biomarker panel for GC metastatic prediction and therapy.

The Macrophage-Associated LncRNA MALR Facilitates ILF3 Liquid-Liquid Phase Separation to Promote HIF1α Signaling in Esophageal Cancer.

SIGNIFICANCE: Secretion of TNFα by tumor-associated macrophages stimulates cancer cells to upregulate lncRNA MALR, which induces ILF3 liquid-liquid phase separation and activation of HIF1α signaling to promote cancer progression.

The liver microenvironment orchestrates FGL1-mediated immune escape and progression of metastatic colorectal cancer.

Colorectal cancer (CRC) patients with liver metastases usually obtain less benefit from immunotherapy, and the underlying mechanisms remain understudied. Here, we identify that fibrinogen-like protein 1 (FGL1), secreted from cancer cells and hepatocytes, facilitates the progression of CRC in an intraportal injection model by reducing the infiltration of T cells. Mechanistically, tumor-associated macrophages (TAMs) activate NF-ĸB by secreting TNFα/IL-1ß in the liver microenvironment and transcriptionally upregulate OTU deubiquitinase 1 (OTUD1) expression, which enhances FGL1 stability via deubiquitination. Disrupting the TAM-OTUD1-FGL1 axis inhibits metastatic tumor progression and synergizes with immune checkpoint blockade (ICB) therapy. Clinically, high plasma FGL1 levels predict poor outcomes and reduced ICB therapy benefits. Benzethonium chloride, an FDA-approved antiseptics, curbs FGL1 secretion, thereby inhibiting liver metastatic tumor growth. Overall, this study uncovers the critical roles and posttranslational regulatory mechanism of FGL1 in promoting metastatic tumor progression, highlighting the TAM-OTUD1-FGL1 axis as a potential target for cancer immunotherapy.