No abstract

Esophageal cancer is one of the most lethal cancers worldwide with poor survival and limited therapeutic options. The discovery of microRNAs created a new milestone in cancer research. miR-377 is located in chromosome region 14q32, which is frequently deleted in esophageal squamous cell carcinoma (ESCC), but the biological functions, clinical significance and therapeutic implication of miR-377 in ESCC are largely unknown. In this study, we found that miR-377 expression was significantly downregulated in tumor tissue and serum of patients with ESCC. Both tumor tissue and serum miR-377 expression levels were positively correlated with patient survival. Higher serum miR-377 expression was inversely associated with pathologic tumor stage, distant metastasis, residual tumor status and chemoradiotherapy resistance. The roles of miR-377 in suppressing tumor initiation and progression, and the underlying molecular mechanisms were investigated. Results of in vitro and in vivo experiments showed that miR-377 overexpression inhibited the initiation, growth and angiogenesis of ESCC tumors as well as metastatic colonization of ESCC cells, whereas silencing of miR-377 had opposite effects. Mechanistically, miR-377 regulated CD133 and VEGF by directly binding to their 3′ untranslated region. Moreover, systemic delivery of formulated miR-377 mimic not only suppressed tumor growth in nude mice but also blocked tumor angiogenesis and metastasis of ESCC cells to the lungs without overt toxicity to mice. Collectively, our study established that miR-377 plays a functional and significant role in suppressing tumor initiation and progression, and may represent a promising non-invasive diagnostic and prognostic biomarker and therapeutic strategy for patients with ESCC.

Despite success in hematologic malignancies, the treatment landscape of chimeric antigen receptor (CAR) T cell therapy for solid tumors remains limited. Claudin18.2 (CLDN18.2)-redirected CAR T cells showed promising efficacy against gastric cancer (GC) in a preclinical study. Here we report the interim analysis results of an ongoing, open-label, single-arm, phase 1 clinical trial of CLDN18.2-targeted CAR T cells (CT041) in patients with previously treated, CLDN18.2-positive digestive system cancers (NCT03874897). The primary objective was safety after CT041 infusion; secondary objectives included CT041 efficacy, pharmacokinetics and immunogenicity. We treated 37 patients with one of three CT041 doses: 2.5 × 108, 3.75 × 108 or 5.0 × 108 cells. All patients experienced a grade 3 or higher hematologic toxicity. Grade 1 or 2 cytokine release syndrome (CRS) occurred in 94.6% of patients. No grade 3 or higher CRS or neurotoxicities, treatment-related deaths or dose-limiting toxicities were reported. The overall response rate (ORR) and disease control rate (DCR) reached 48.6% and 73.0%, respectively. The 6-month duration of response rate was 44.8%. In patients with GC, the ORR and DCR reached 57.1% and 75.0%, respectively, and the 6-month overall survival rate was 81.2%. These initial results suggest that CT041 has promising efficacy with an acceptable safety profile in patients with heavily pretreated, CLDN18.2-positive digestive system cancers, particularly in those with GC.

No abstract

Purpose: By using cDNA microarray analysis, we identified a transcriptional factor, SOX6, was frequently downregulated in esophageal squamous cell carcinoma (ESCC). The aim of this study is to investigate the role of SOX6 in human esophageal cancer development, and to examine the prevalence and clinical significance of SOX6 downregulation in ESCC.Experimental Design: Expressions of SOX6 mRNA in 50 ESCCs and SOX6 protein in 300 ESCCs were investigated by semiquantitative RT-PCR and immunohistochemistry, respectively. The tumor-suppressive function of SOX6 was characterized by cell growth, foci formation, wound-healing and cell invasive assays, and tumor xenograft experiment. Western blot analysis was applied to detect protein expression levels.Results: SOX6 was frequently downregulated in primary ESCCs in both mRNA level (29/50, 58%) and protein level (149/219, 68.0%), which was significantly associated with the poor differentiation (P ¼ 0.029), lymph node metastases (P ¼ 0.014), advanced TNM stage (P ¼ 0.000), and disease-specific survival (P < 0.001). Multivariate analysis indicated that the downregulation of SOX6 (P ¼ 0.000) was a significant independent prognostic factors for ESCC. Functional studies showed that SOX6 was able to suppress both in vitro and in vivo tumorigenic ability of ESCC cells. The tumor-suppressive mechanism of SOX6 was associated with its role in G1/S cell-cycle arrest by upregulating expressions of p53 and p21 WAF1/CIP1 and downregulating expressions of cyclin D1/CDK4, cyclin A, and b-catenin. Conclusions:We provided the first evidence that SOX6 is a novel tumor-suppressor gene in ESCC development and is a potential prognostic marker in ESCC.

Sintilimab plus chemotherapy (chemo) versus chemo as first-line treatment for advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma (ORIENT-16): First results of a randomized, double-blind, phase III study

Deletion of 3p is one of the most frequent chromosomal alterations in many solid tumors, including esophageal squamous cell carcinoma (ESCC), suggesting the existence of one or more tumor-suppressor genes at 3p. Recently, our loss of heterozygosity study revealed that 3p22 was frequently deleted in ESCC and a candidate tumor-suppressor gene (TSG), phospholipase C-d1 (PLCd1), was identified within the 3p22 region. In this study, absent expression of PLCd1 was detected in 26 of 50 (52%) primary ESCCs and 4 of 9 (44.4%) ESCC cell lines, which was significantly associated with DNA copy number loss and promoter hypermethylation (P < 0.05). Functional studies showed that PLCd1 was able to suppress both in vitro and in vivo tumorigenic ability of ESCC cells, including foci formation, colony formation in soft agar, and tumor formation in nude mice. The tumor-suppressive mechanism of PLCd1 was associated with its role in the cell cycle arrest at the G 1 -S checkpoint by up-regulation of p21 and down-regulation of phosphorylated Akt (Ser 473 ). In addition, down-regulation of PLCd1 protein was significantly correlated with ESCC metastasis (P = 0.014), which was associated with its function in increasing cell adhesion and inhibiting cell mobility. Taken together, our results suggest that PLCd1 plays an important suppressive role in the development and progression of ESCC. [Cancer Res 2007;67(22):10720-6]

MicroRNAs (miRNAs) play a critical role in development and progression of cancers. Deregulation of MicroRNA-9 (miR-9) has been documented in many types of cancers but their role in the development of esophageal squamous cell carcinoma (ESCC) has not been studied. This study aimed to investigate the effect of miR-9 in esophageal cancer metastasis. The up-regulation of miR-9 was frequently detected in primary ESCC tumor tissue, which was significantly associated with clinical progression (P = 0.022), lymph node metastasis (P = 0.007) and poor overall survival (P < 0.001). Functional study demonstrated that miR-9 promoted cell migration and tumor metastasis, which were effectively inhibited when expression of miR-9 was silenced. Moreover, we demonstrated that miR-9 interacted with the 3′-untranslated region of E-cadherin and down-regulated its expression, which induced β-catenin nuclear translocation and subsequently up-regulated c-myc and CD44 expression. In addition, miR-9 induced epithelial-mesenchymal transition (EMT) in ESCC, a key event in tumor metastasis. Taken together, our study demonstrates that miR-9 plays an important role in ESCC metastasis by activating β-catenin pathway and inducing EMT via targeting E-cadherin. Our study also suggests miR-9 can be served as a new independent prognostic marker and/or as a novel potential therapeutic target for ESCC.