DDX18 Facilitates the Tumorigenesis of Lung Adenocarcinoma by Promoting Cell Cycle Progression through the Upregulation of CDK4.

Lung adenocarcinoma (LUAD) is the most prevalent and aggressive subtype of lung cancer, exhibiting a dismal prognosis with a five-year survival rate below 5%. DEAD-box RNA helicase 18 (DDX18, gene symbol DDX18), a crucial regulator of RNA metabolism, has been implicated in various cellular processes, including cell cycle control and tumorigenesis. However, its role in LUAD pathogenesis remains elusive. This study demonstrates the significant upregulation of DDX18 in LUAD tissues and its association with poor patient survival (from public databases). Functional in vivo and in vitro assays revealed that DDX18 knockdown potently suppresses LUAD progression. RNA sequencing and chromatin immunoprecipitation experiments identified cyclin-dependent kinase 4 (CDK4), a cell cycle regulator, as a direct transcriptional target of DDX18. Notably, DDX18 depletion induced G1 cell cycle arrest, while its overexpression promoted cell cycle progression even in normal lung cells. Interestingly, while the oncogenic protein c-Myc bound to the DDX18 promoter, it did not influence its expression. Collectively, these findings establish DDX18 as a potential oncogene in LUAD, functioning through the CDK4-mediated cell cycle pathway. DDX18 may represent a promising therapeutic target for LUAD intervention.

The role of 18F-FDG PET/CT in predicting the pathological response to neoadjuvant PD-1 blockade in combination with chemotherapy for resectable esophageal squamous cell carcinoma.

PURPOSE: Accurate assessment of residual disease of tumor and lymph nodes after neoadjuvant immunochemotherapy is crucial in the active surveillance for patients with pathological complete response (pCR) and the optimal extent of lymphadenectomy for patients with non-pCR. This post hoc analysis aimed to evaluate the performance of 18F-FDG PET/CT to predict the pathological response to neoadjuvant immunochemotherapy for esophageal squamous cell carcinoma (ESCC). METHODS: Fifty-eight resectable ESCC patients received two cycles of camrelizumab in combination with chemotherapy and were enrolled in the final analysis. The 18F-FDG PET/CT scans were acquired at baseline (scan-1) and after immunochemotherapy but prior to surgery (scan-2). Maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), tumor-to-blood pool SUVmax ratio (SUVTBR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were evaluated for their association with the pathological response to immunochemotherapy. RESULTS: Nineteen patients (32.8%, 19/58) had pCR and thirty-nine patients (67.2%, 39/58) had non-pCR after two doses of camrelizumab and chemotherapy. At scan-2, the SUVmax, SUVmean, SUVTBR, TLG, and MTV were significantly lower in pCR than in non-pCR patients. Decrease in TLG and MTV between scan-2 and scan-1 of the same patient was significantly higher in the pCR than in the non-pCR group. In the receiver operating characteristic curve analysis, SUVmax, SUVmean, SUVTBR, TLG, and MTV in scan-2 showed excellent predictive value for the pCR of primary tumors. Furthermore, SUVmax in scan-2 were higher in positive lymph nodes than in negative ones, suggesting a high negative predictive ability (98.6%) with a cut-off value at 1.4. CONCLUSION: The parameters of 18F-FDG PET/CT have the excellent performance for predicting pCR after the combined neoadjuvant immunochemotherapy in resectable ESCC. TRIAL REGISTRATION: ChiCTR2000028900. Registered on January 6, 2020.

The characteristics and prognostic significance of esophageal squamous cell carcinoma with synchronous multiple lesions: over 10-year experience.

PURPOSE: Esophageal squamous cell carcinoma (ESCC) is occasionally observed with synchronous multiple tumor lesions. Our study is aiming to define the clinical and prognostic features of this pathological subtype. METHODS: This study included a large cohort of 1126 ESCC patients received esophagectomy with systemic lymph-node dissection between 2003 and 2013 in Sun Yat-sen University Cancer Center. The characteristics and prognostic significance of ESCC with multiple lesions were analyzed. The propensity score matching was performed to balance the baseline clinical characteristics. RESULTS: A total of 103 patients (9.1%) with 216 synchronous multiple lesions were identified from postoperative gross samples. Among them, 94 patients had two lesions, and 8 patients had three lesions, while only one patient had four lesions. The consistency of pT stages and histological grade among tumor lesions from the same gross sample were 19.4% (20/103) and 37.9% (39/103), respectively. Additionally, the tumor sites, sizes, and even the pathological subtypes can be variant in one patient. The preoperative upper gastrointestinal endoscopy could only identified 80.1% of the multiple tumor lesions. The male gender (P = 0.012), positive personal cancer history (P < 0.001), and higher pN stages (P < 0.001) were independent risk factors for synchronous multiple lesions. Patients with multiple lesions showed significantly lower survival rate (P = 0.002), and the multiple-lesion was an independently adverse prognostic factor in operable ESCC (P = 0.002). CONCLUSION: ESCC with multiple lesions had unique clinical features and should not be simply treated as the one-lesion ESCC. Due to its worse prognostic impact, advanced multidisciplinary therapies should be considered for patients with multiple esophageal tumor lesions.

A Novel Diagnosis Method Based on Methylation Analysis of SHOX2 and Serum Biomarker for Early Stage Lung Cancer.

OBJECTIVES: Lung cancer (LC) is often accompanied by significant methylation abnormalities. This study aimed to develop a decision tree (DT) accompanied the stature homeobox 2 gene (SHOX2) / prostaglandin E receptor 4 (PTGER4) gene DNA methylation with traditional tumor marker in the differential diagnosis of benign and malignant lung nodule. METHODS: We performed a study with 104 patients enrolled in the LC group and 36 patients in the benign lung diseases group. All the clinical data of these patients were collected through electronic medical record. Total Methylation (TM) status of both SHOX2 and PTGER4 was defined as methylation levels of SHOX2 plus methylation levels of PTGER4. One-way analysis was used to compare the concentrations of serum samples and t-test was used to compare pairwise mean values between groups. Receiver operating curve (ROC) was used to evaluate the diagnostic value. Furthermore, the strategy was validated in 19 LC patients and 11 patients with benign lung diseases. RESULTS: There were significant differences between the concentration of neuron-specific enolase (NSE), carcinoembryonic antigen (CEA), cytokeratin 19 fragments (CYFRA21 -1) and the methylation levels of SHOX2, PTGER4 and TM in lung benign diseases and cancer group. The AUCs of NSE, CEA, CYFRA21 -1, Methylation SHOX2, Methylation PTGER4 and TM were 0.721 (95% CI: 0.627-0.816), 0.753 (95% CI: 0.673-0.833) and 0.778(95% CI: 0.700-0.856), 0.851(0.786-0.916), 0.847(0.780-0.913) and 0.861(0.800-0.922) respectively. We developed a DT model with TM and CYFRA21 -1 used in this study, and the area under the curve (AUC) of DT was 0.921 and the sensitivity up to 0.856. In the validation cohort, the AUC of SHOX2, PTGER4 and TM was also much higher than traditional serum markers. CONCLUSIONS: Our results indicated that the DT model calculated from the TM and CYFRA21 -1 can accurately classify LC and benign diseases, which showed better diagnostic performance than traditional serum parameter.

Prophylactic thoracic duct ligation is associated with poor prognosis and regional lymph node relapse in esophageal squamous cell carcinoma.

OBJECTIVES: The ligation of thoracic duct interrupts the normal lymphatic circulation. Whether the ligation of thoracic duct would affect tumor recurrence and patient survival is unclear. METHODS: The correlations between prophylactic thoracic duct ligation (PLG) and prognosis were examined in patients with esophageal squamous cell carcinoma. Patients who received Ivor Lewis or McKeown esophagectomy with systemic lymph node dissection and R0 resection between 2003 and 2013 in Sun Yat-sen University Cancer Center were included in the study. RESULTS: A total number of 473 and 462 were included in the PLG group and non-prophylactic thoracic duct ligation (NPLG) group, respectively. The PLG group had a lower 5-year survival rate (48.2% vs 61.6%, P < .001). After a 1:1 propensity score matching, 874 cases (437 pairs) were included and the survival analysis showed that PLG was associated with worse 5-year cumulative survival of 48.6% vs 61.6% in those patients without ligation (P < .001). The multivariate analysis revealed that PLG was an independent factor for poor prognosis after esophagectomy (hazard ratio, HR = 1.56; 95% confidence interval, 95% CI, 1.26-1.93, P < .001). Additionally, PLG was associated with regional lymph node relapse (P = .015). CONCLUSIONS: PLG should not be performed routinely if no sign of thoracic duct rupture or tumor invasion were identified.

Effect of Prophylactic Thoracic Duct Ligation in Reducing the Incidence of Postoperative Chylothorax during Esophagectomy: A Systematic Review and Meta-analysis.

OBJECTIVES: There is no consensus on the effectiveness of prophylactic thoracic duct ligation (PLG) in esophagectomy for reducing the incidence of postoperative chylothorax. We performed a systemic review and meta-analysis to study its efficacy. METHODS: A systemic review of the publications was performed on three databases to identify all the relevant literature on comparative outcomes of PLG and nonprophylactic thoracic duct ligation (NPLG). The primary end point was the incidence of postoperative chylothorax. RESULTS: Seven studies with comparative data on PLG (n = 2,178) versus NPLG (n = 3,048) were identify from the current publications. Comparison showed no significant difference between PLG and NPLG on the incidence of postoperative chylothorax (relative risk = 0.431; 95% confidence interval, 0.186 to 1.002; p = 0.050). CONCLUSIONS: Although some studies showed that PLG during the esophagectomy was effective to lower the incidence of postoperative chylothorax, no evidence was observed in the present meta-analysis. Further research is warranted to validate the findings.

Impact of alcohol consumption on survival in patients with esophageal carcinoma: a large cohort with long-term follow-up.

Alcohol is a well-established cause of esophageal carcinoma, but its effect on survival is little known and contradictory. To clarify whether drinking is an independent predictor of survival in esophageal carcinoma, 2151 Chinese patients, receiving surgical resection from January 1997 to December 2008, were followed until March 2014. Cox proportional hazards analysis was applied to evaluate the prognostic effect of alcohol consumption. The median follow-up was 64 months. The median overall survival (OS; 42 months) and disease-free survival (DFS; 33 months) for never-drinkers were significantly higher than ever-drinkers (27 and 22 months, respectively). In the multivariate Cox model that was adjusted for age, weight loss, stage according to criteria set by the American Joint Committee on Cancer, radicality of surgery, adjuvant treatment, smoking status, and gender, the hazard ratios of ever-drinking were 1.22 (1.06-1.41, P = 0.005) on OS, and 1.16 (1.01-1.34, P = 0.037) on DFS. The hazardous effect on OS and DFS of drinking grew statistically significantly in a dose-dependent manner with increasing amount of alcohol consumption per day (both P-value for trend < 0.05). The predictive effect of drinking on OS (P = 0.596) or DFS (P = 0.207) was not significant in the subgroup with esophageal adenocarcinoma (n = 195). The current study revealed that the survival is shortened, of those patients who consume alcohol before diagnosis of esophageal squamous cell carcinoma, which are not attributable to differences in stage, smoking status, and gender. Alcohol control should be emphasized to reduce mortality of esophageal carcinoma, and further outcome studies should include alcohol as a potential prognosticator.

RNA modification-related genes illuminate prognostic signature and mechanism in esophageal squamous cell carcinoma.

Emerging studies have demonstrated the link between RNA modifications and various cancers, while the predictive value and functional mechanisms of RNA modification-related genes (RMGs) in esophageal squamous cell carcinoma (ESCC) remain unclear. Here we established a prognostic signature for ESCC based on five RMGs. The analysis of ESCC clinical samples further verified the prognostic power of the prognostic signature. Moreover, we found that the knockdown of NSUN6 promotes ESCC progression in vitro and in vivo, whereas the overexpression of NSUN6 inhibits the malignant phenotype of ESCC cells. Mechanically, NSUN6 mediated tRNA m5C modifications selectively enhance the translation efficiency of CDH1 mRNA in a codon dependent manner. Rescue assays revealed that E-cadherin is an essential downstream target that mediates NSUN6's function in the regulation of ESCC progression. These findings offer additional insights into the link between ESCC and RMGs, as well as provide potential strategies for ESCC management and therapy.

Correlation of p53 status with the response to chemotherapy-based treatment in esophageal cancer: a meta-analysis.

BACKGROUND: The value of p53 status for predicting response to chemotherapy-based treatment in patients with esophageal cancer has been controversial. We conducted a meta-analysis to elucidate the correlation of p53 status with the response to chemotherapy-based treatment. METHODS: Studies were searched in PubMed, Embase, and Web of Science (up to September 2012). The p53 status and response to therapy were defined and standardized. Subgroup analyses based on the treatment and histopathology were performed to explore the usefulness of p53 status for predicting response to therapy in esophageal cancer. Sensitivity analyses were conducted by removing specific studies to assess the effects of study quality. RESULTS: We included 28 studies with 1497 cases in our meta-analysis. Wild-type form of p53 status (low expression of p53 protein and/or wild-type p53 gene) was associated with high response to chemotherapy-based treatment in esophageal cancer (total major response [MR]: risk ratio [RR] = 1.09, 95 % CI = 1.03-1.16, P = .003; pathological MR: RR = 1.15, 95 % CI = 1.06-1.25, P = .001; total complete response [CR]: RR = 1.08, 95 % CI = 1.00-1.17, P = .040). The similar correlation between the wild-type form p53 and response to therapy were also detected in subgroup analyses (total MR, pathological MR, and total CR in chemoradiotherapy subgroup; total MR in chemotherapy subgroup; total MR and pathological CR in esophageal squamous cell carcinoma [ESCC]). Additionally, patients with wild-type form p53 status had high pathological complete response rate to neoadjuvant chemoradiotherapy in ESCC. CONCLUSIONS: The current meta-analysis suggested that p53 status might be a predictive biomarker for response to chemotherapy-based treatment in esophageal cancer.

Prognostic value of HOXB7 mRNA expression in human oesophageal squamous cell cancer.

OBJECTIVE: This study was to determine the role of HOXB7 in predicting outcomes of patients with oesophageal squamous cell cancer (OSCC). METHODS: Samples were collected from 179 OSCC patients. HOXB7 mRNA expression was measured by quantitative real-time polymerase chain reaction. RESULTS: HOXB7 mRNA expression was up-regulated in 85.1% of OSCC tumorous tissues, and correlated with age, pathological T and N category, as well as cancer-specific survival (CSS). However, subgroup analysis revealed its discernibility on CSS was only pronounced in early stage. CONCLUSIONS: HOXB7 mRNA expression might serve as a novel prognostic biomarker for resected OSCC patients in early stage.

Ten-year survival of patients with oesophageal squamous cell carcinoma.

OBJECTIVES: The standard predictive factors of actuarial survival such as T and N stage become less important as patients live for more than 10 years after treatment of cancer. Reports of actual 10-year survivors of oesophageal squamous cell carcinoma (SCC) are rare, and demographic and clinicopathological factors associated with 10-year survival have not been well documented. In this research we evaluated factors predictive of actual, as opposed to actuarial, 10-year survival. METHODS: We retrospectively analysed 1 046 patients who had undergone oesophagectomy for oesophageal SCC. The demographic and clinicopathological characteristics of patients who were alive more than 10 years after oesophagectomy and those of patients who had died were compared. RESULTS: Univariate analysis showed that 18 factors differed significantly between the two groups. Based on logistic regression analysis, factors associated with 10-year survival were younger age, female gender, absence of dysphagia, a left transthoracic surgical approach, lower pathological T stage, and fewer metastatic lymph nodes. CONCLUSION: The independent positive predictors of actual as opposed to actuarial 10-year survival are younger age, female gender, absence of dysphagia, lower pathological T stage, and fewer metastatic lymph nodes.

Intratumoral microbiome impacts immune infiltrates in tumor microenvironment and predicts prognosis in esophageal squamous cell carcinoma patients.

Background: Different intratumoral microbiotaexist in different tumors and play a crucial function in carcinogenesis. However, whether they impact clinical outcomes in esophageal squamous cell carcinoma (ESCC) and their mechanism remain unclear. Methods: 16S rDNA amplicon sequencing was performed on surgically resected samples from 98 ESCC patients to analyze intratumoral microbiome abundance and composition. Multiplex fluorescent immunohistochemistry staining was used to profile the phenotypes of immune infiltrates in the tumor microenvironment (TME). Results: Patients with higher intratumoral Shannon index had significantly worse surgical outcomes. When patients were divided into short-term survivors and long-term survivors based on the median survival time, both intratumoral alpha-diversity and beta-diversity were found to be significantly inconsistent, and the relative abundance of Lactobacillus and Leptotrichia emerged as the two microorganisms that probably influenced the survival of ESCC patients. Only Lactobacillus in ESCC was validated to significantly worsen patients' prognoses and to be positively correlated with the Shannon index. Multivariate analysis revealed that the intratumoral Shannon index, the relative abundance of Lactobacillus, and the pathologic tumor-node-metastasis (pTNM) stage were independently associated with patients' overall survival. Furthermore, the relative abundance of both Lactobacillus and Shannon index was positively correlated with the proportions of PD-L1+ epithelial cells (ECs) and tumor-associated macrophages (TAMs). The Shannon index was negatively correlated with the proportions of natural killer (NK) cells in the TME. Conclusions: A high abundance of intratumoral Lactobacillus and bacterial alpha-diversity was associated with the formation of the immunosuppressive TME and predicted poor long-term survival in ESCC patients.

NAT10-mediated ac4C tRNA modification promotes EGFR mRNA translation and gefitinib resistance in cancer.

Aberrant RNA modifications are frequently associated with cancers, while the underlying mechanisms and clinical significance remain poorly understood. Here, we find that the ac4C RNA acetyltransferase NAT10 is significantly upregulated in esophageal cancers (ESCAs) and associated with poor ESCA prognosis. In addition, using ESCA cell lines and mouse models, we confirm the critical functions of NAT10 in promoting ESCA tumorigenesis and progression in vitro and in vivo. Mechanistically, NAT10 depletion reduces the abundance of ac4C-modified tRNAs and decreases the translation efficiencies of mRNAs enriched for ac4C-modified tRNA-decoded codons. We further identify EGFR as a key downstream target that facilitates NAT10's oncogenic functions. In terms of clinical significance, we demonstrate that NAT10 depletion and gefitinib treatment synergistically inhibit ESCA progression in vitro and in vivo. Our data indicate the mechanisms underlying ESCA progression at the layer of mRNA translation control and provide molecular insights for the development of effective cancer therapeutic strategies.

Efficiency of ectopic thymectomy by three surgical approaches in non-thymomatous myasthenia gravis.

BACKGROUND: To explore the efficiency of ectopic thymectomy by the three surgical approaches of trans-sternum, right unilateral thoracoscopy and thoracoscopic subxiphoid in patients with non-thymomatous myasthenia gravis. METHODS: 155 consecutive non-thymomatous myasthenia gravis patients who underwent extended thymectomy by 3 approaches including trans-sternum, right unilateral thoracoscopy and thoracoscopic subxiphoid in 1st affiliated hospital of Sun Yat-Sen University from January 2017 to October 2019 were reviewed. Differences of perioperative clinical characteristics in three surgical approaches were analyzed. RESULTS: Time to onset of myasthenia gravis (early or late) (p = 0.018), blood loss (p < 0.001), duration of operation (p = 0.031), duration and volume of thoracic drainage (p = 0.039 and p = 0.026), length of hospitalization (p = 0.039), the efficiency of ectopic thymectomy (p = 0.037), and the detection rate of ectopic thymus in the second quadrant (p = 0.018) were different among the three surgical approaches. In univariate logistic regression analysis, higher efficiency of ectopic thymectomy were associated with transsternal (OR 2.36, 95% CI 1.32-4.22, p = 0.011) and thoracoscopic subxiphoid approaches (OR 2.07, 95% CI 1.12-3.82, p = 0.033). In the multiple logistic regression analysis, the transsternal approach (OR 2.02, 95% CI 1.10-3.71, p = 0.024) was an independent protective factor for the efficiency of ectopic thymectomy. CONCLUSIONS: Both the right unilateral thoracoscopic and thoracoscopic subxiphoid approaches have advantages over the transsternal approach in short-term postoperative recovery. Transsternal approach is still the best choice for ectopic thymectomy while thoracoscopic subxiphoid approach show the potential as an alternative way.

Family history of cancer is a prognostic factor for better survival in operable esophageal squamous cell carcinoma: A propensity score matching analysis.

Lay summary: Patients with a family history of cancer, especially digestive tract cancer and esophageal cancer, a family history of cancer in the first degree, and more than one relative affected by cancer were associated with favorable survival when compared to those without a family history of cancer. Precis for use in the Table of Contents: A family history of cancer is a favorable independent prognostic factor in ESCC. Patients with a family history of cancer, especially digestive tract cancer and esophageal cancer, a family history of cancer in the first degree, and more than one relative affected by cancer were associated with favorable survival when compared to those without a family history of cancer. Background: A family history of cancer (FH) is closely associated with the risk and survival of many cancers. However, the effect of FH on the prognosis of patients with esophageal squamous cell carcinoma (ESCC) remains unclear. We performed a large cohort study in the Chinese population to obtain insight into the prognostic value of FH in patients with operable ESCC. Methods: A total of 1,322 consecutive patients with thoracic ESCC who had undergone esophagectomy between January 1997 and December 2013 were included. The FH group included patients with any degree of FH, while the non-FH group included patients without any degree of FH. In total, 215 patients with FH and 215 without FH were matched using the propensity score matching analysis method to adjust for differences in baseline variables between the two groups. The impact of FH on disease-free survival (DFS) and overall survival (OS) was estimated using the Kaplan-Meier method and Cox's proportional hazards models. Results: Before matching, 280 (21.2%) patients were included in the FH group and 1,042 (78.8%) in the non-FH group. FH was associated with early pathological T stage (p = 0.001), lymph node-negative status (p = 0.022), and early pathological stage (p = 0.006). After matching, FH was an independent prognostic factor for DFS and OS in ESCC patients. Patients with FH had 35% lower risk of disease progression (hazard ratio [HR] = 0.65, 95% CI: 0.51-0.84, p = 0.001) and 34% lower risk of death (HR = 0.66, 95% CI: 0.51-0.86, p = 0.002) than those without FH. Patients with a family history of digestive tract cancer (FH-DC), a family history of esophageal cancer (FH-EC), FH in first-degree relatives (FH-FD), and more than one relative affected by cancer were associated with favorable DFS and OS as compared to those without FH. Conclusion: FH is a favorable independent prognostic factor in ESCC. Patients with FH, especially those with FH-DC, FH-EC, FH-FD, and more than one relative affected by cancer, had improved survival.

Clinical significance and outcomes of bilateral and unilateral recurrent laryngeal nerve lymph node dissection in esophageal squamous cell carcinoma: A large-scale retrospective cohort study.

BACKGROUND: The survival benefits of recurrent laryngeal nerve lymph node dissection (RLNLD) in esophageal squamous cell carcinoma (ESCC) are still under debate, and the prognostic value of unilateral RLNLD has been rarely studied. Therefore, the aim of the present study was to investigate the clinical significance and outcomes of RLNLD in ESCC in a large-scale cohort study, to shed light on the outcomes of unilateral RLNLD, and to identify the factors that affect the prognostic outcome of RLNLD. METHODS: We retrospectively reviewed 1153 patients with thoracic ESCC who underwent right thoracotomy with lymphadenectomy. The impact of RLNLD on disease-free survival (DFS) and overall survival (OS) was estimated using the Kaplan-Meier method and Cox proportional hazard models. Inverse probability of treatment weighting (IPTW) was performed to adjust for differences in baseline variables in pairwise comparisons. Subgroup analysis of survival and postoperative complications was conducted for selective RLNLD. RESULTS: RLN lymph node (LN) metastasis was independently associated with tumor location and most other LN station metastases. RLNLD was an independent prognostic factor for DFS and OS. Both patients who underwent unilateral and bilateral RLNLD had significantly better DFS and OS than the non-RLNLD patients. Furthermore, pairwise comparisons with IPTW confirmed these results, and we found that patients who underwent bilateral RLNLD had better survival than those who underwent unilateral RLNLD. However, subgroup analysis showed that there was no survival benefit and higher morbidity after bilateral RLNLD for patients with cancer in the lower thoracic esophagus, and elderly and female patients. CONCLUSION: RLN LN metastasis is very frequent in ESCC, and both unilateral and bilateral RLNLD have considerable survival benefits. Selective RLNLD with better survival and lower morbidity was recommend for some defined subgroups.

N7-methylguanosine tRNA modification promotes esophageal squamous cell carcinoma tumorigenesis via the RPTOR/ULK1/autophagy axis.

Mis-regulated RNA modifications promote the processing and translation of oncogenic mRNAs to facilitate cancer progression, while the molecular mechanisms remain unclear. Here we reveal that tRNA m7G methyltransferase complex proteins METTL1 and WDR4 are significantly up-regulated in esophageal squamous cell carcinoma (ESCC) tissues and associated with poor ESCC prognosis. In addition, METTL1 and WDR4 promote ESCC progression via the tRNA m7G methyltransferase activity in vitro and in vivo. Mechanistically, METTL1 or WDR4 knockdown leads to decreased expression of m7G-modified tRNAs and reduces the translation of a subset of oncogenic transcripts enriched in RPTOR/ULK1/autophagy pathway. Furthermore, ESCC models using Mettl1 conditional knockout and knockin mice uncover the essential function of METTL1 in promoting ESCC tumorigenesis in vivo. Our study demonstrates the important oncogenic function of mis-regulated tRNA m7G modification in ESCC, and suggest that targeting METTL1 and its downstream signaling axis could be a promising therapeutic target for ESCC treatment.

Phenotypic profiling and prognostic significance of immune infiltrates in esophageal squamous cell carcinoma.

The tumor microenvironment (TME) of esophageal squamous cell carcinoma (ESCC) impacts tumor progression but is poorly understood. We obtained tumor tissues from 279 patients after esophagectomy and characterized the TME in intraepithelial and stromal regions using multiplex fluorescent immunohistochemistry (mfIHC). A heterogeneous immune population infiltrating tumor and the uninvolved esophageal tissue were observed. The infiltration of intraepithelial programmed death ligand 1 (PD-L1)-positive tumor-associated macrophages (TAMs) and stromal granzyme B+ activated cytotoxic T cells (aCTLs) correlated with both prolonged overall survival (OS) and disease-free survival (DFS). The intraepithelial memory T cell infiltration predicted longer OS, while intraepithelial and stromal regulatory T cell (Treg) infiltration was associated with shortened OS and DFS, respectively. Multivariate models combining immune infiltrates and clinicopathological factors outperformed tumor-node-metastasis (TNM) stage in predicting OS and DFS at 3 and 5 years. The infiltration of Treg inversely correlated with that of the antitumor effectors including CTLs, aCTLs, and natural killer (NK) cells. Intraepithelial memory T cell infiltration also negatively correlated with PD-L1 expression. In spatial analysis, intraepithelial dendritic cell (DC)-memory T cell engagement increased in high PD-L1+ TAM infiltration group. The characterization of the TME revealed a complex interplay between immune populations and may be employed to stratify patient for prognosis prediction and immunotherapy.

METTL3-mediated m6A mRNA modification promotes esophageal cancer initiation and progression via Notch signaling pathway.

Esophageal cancer is a lethal malignancy with a high mortality rate, while the molecular mechanisms underlying esophageal cancer pathogenesis are still poorly understood. Here, we found that the N6-methyladenosine (m6A) methyltransferase-like 3 (METTL3) is significantly upregulated in esophageal squamous cell carcinoma (ESCC) and associated with poor patient prognosis. Depletion of METTL3 results in decreased ESCC growth and progression in vitro and in vivo. We further established ESCC initiation and progression models using Mettl3 conditional knockout mouse and revealed that 3METTL3-mediated m6A modification promotes ESCC initiation and progression in vivo. Moreover, using METTL3 overexpression ESCC cell model and Mettl3 conditional knockin mouse model, we demonstrated the critical function of METTL3 in promoting ESCC tumorigenesis in vitro and in vivo. Mechanistically, METTL3-catalyzed m6A modification promotes NOTCH1 expression and the activation of the Notch signaling pathway. Forced activation of Notch signaling pathway successfully rescues the growth, migration, and invasion capacities of METTL3-depleted ESCC cells. Our data uncovered important mechanistical insights underlying ESCC tumorigenesis and provided molecular basis for the development of novel strategies for ESCC diagnosis and treatment.

Preoperative weight loss is associated with poorer prognosis in operable esophageal cancer patients: A single-center retrospective analysis of a large cohort of Chinese patients.

Background: Preoperative weight loss has been shown to be a prognostic factor for many cancers. However, whether preoperative weight loss has clinical significance in patients with esophageal cancer is still controversial. Methods: A total of 2,174 Chinese patients underwent radical resection of esophageal cancer from 2000 to 2008 were included in our study. Patients were divided into two group: no weight loss (-) and weight loss (+), according to whether they had weight loss compared with their usual weight at diagnosis. The influence of preoperative weight loss on disease-free survival (DFS) and overall survival (OS) was estimated using the Kaplan-Meier method and Cox proportional hazard models. Results: weight loss (+) was significantly associated with age (P=0.001), alcoholism (P<0.001), tumor location (P=0.003), pT category (P=0.003), pN category (P=0.001). Patients of group weight loss (+) had significantly poorer DFS (Mean: 63.3 months (m) vs 76.8 m, P<0.001) and OS (67.4 m vs 83.3 m, P<0.001) than the no weight loss (-) group. In the final multivariate survival analysis with adjustment for covariates, we found that the weight loss (+) group had a 19% higher risk of death (HR=1.19, 95%CI: 1.07-1.33, P=0.002) and had a 13% higher risk of disease progression (HR=1.13, 95%CI: 1.01-1.25, P=0.027), respectively, than the no weight loss (-) group. Subgroup analysis indicated that the association with preoperative weight loss and better DFS or OS was observed in patients with esophageal squamous cell carcinoma (ESCC) and early pathological stage (I-II). Conclusion: Preoperative weight loss is associated with shorter OS and DFS, which means poor postoperative prognosis in esophageal cancer patients.