BackgroundPrevious work has shown reduced expression levels of let-7 in lung tumors. But little is known about the expression or mechanisms of let-7a in prostate cancer. In this study, we used in vitro and in vivo approaches to investigate whether E2F2 and CCND2 are direct targets of let-7a, and if let-7a acts as a tumor suppressor in prostate cancer by down-regulating E2F2 and CCND2.Methodology/PrincipalFindings Real-time RT-PCR demonstrated that decreased levels of let-7a are present in resected prostate cancer samples and prostate cancer cell lines. Cellular proliferation was inhibited in PC3 cells and LNCaP cells after transfection with let-7a. Cell cycle analysis showed that let-7a induced cell cycle arrest at the G1/S phase. A dual-luciferase reporter assay demonstrated that the 3′UTR of E2F2 and CCND2 were directly bound to let-7a and western blotting analysis further indicated that let-7a down-regulated the expression of E2F2 and CCND2. Our xenograft models of prostate cancer confirmed the capability of let-7a to inhibit prostate tumor development in vivo.Conclusions/SignificanceThese findings help to unravel the anti-proliferative mechanisms of let-7a in prostate cancer. Let-7a may also be novel therapeutic candidate for prostate cancer given its ability to induce cell-cycle arrest and inhibit cell growth, especially in hormone-refractory prostate cancer.

Background: SARS-CoV-2 is a novel human coronavirus, there is no specific antiviral drugs. It has been proved that host-cell-expressed CD147 could bind spike protein of SARS-CoV-2 and involve in host cell invasion. Antibody against CD147 could block the infection of SARS-CoV-2. We aimed to assess the efficacy and safety of meplazumab, a humanized anti-CD147 antibody, as add-on therapy in patients with COVID-19 pneumonia. Methods: All patients received recommended strategy from Diagnosis and Treatment for 2019 Novel Coronavirus Diseases released by National Health Commission of China. Eligible patients were add-on administered 10 mg meplazumab intravenously at days 1, 2, and 5. Patients hospitalized in the same period were observed as concurrent control. The endpoints include virological clearance rate, case severity, chest radiographic, and laboratory test. This trial was approved by the Ethics Committee of Institution at the Tangdu hospital, and registered with ClinicalTrials.gov, NCT 04275245. Findings:17 patients were enrolled and assigned to meplazumab group between Feb 3, 2020 and Feb 10, 2020. 11 hospitalized patients served as concurrent control. Baseline characteristics were generally balanced across two groups. Compared to control group, meplazumab treatment significantly improved the discharged (p=0.006) and case severity (p=0.021) in critical and severe patients. The time to virus negative in meplazumab group was reduced than that in control group (median 3, 95%CI[1.5-4.5] vs. 13, [6.5-19.5]; p=0.014, HR=0.37, 95%CI[0.155-0.833]). The percentages of patients recovered to the normal lymphocyte count and CRP concentration were also increased remarkably and rapidly in meplazumab group. No adverse effect was found in meplazumab-treated patients. Interpretation:Meplazumab efficiently improved the recovery of patients with SARS-CoV-2 pneumonia with a favorable safety profile. Our results support to carry out a large-scale investigation of meplazumab as a treatment for COVID-19 pneumonia. Funding:National Science and Technology Major Project.

CD147 molecule is reported to be correlated with the malignancy of some cancers; however, it remains unclear whether it is involved in the progression of hepatocellular carcinoma (HCC). Here, we investigated the function of HAb18G/CD147, a member of CD147 family, and its antibodies, HAb18 and LICARTIN, in HCC invasion and metastasis. We observed that HAb18G/CD147 gene silence in HCC cells significantly decreased the secretion of matrix metalloproteinase (MMP) and the invasive potential of HCC cells (P < 0.001). MMP silence in HCC cells also significantly suppressed the invasion of the cells when cocultured with fibroblasts; however, its inhibitory effect was significantly weaker than that of both HAb18G/CD147 silence in HCC cells and that of MMP silence in fibroblasts (P < 0.001). Blocking the HAb18G/CD147 molecule on HCC cells with HAb18 monoclonal antibody resulted in a similar suppressive effect on MMP secretion and cell invasion, but with no significant effects on the cell growth. 131 I-labeled HAb18 F(ab ¶) 2 (LICARTIN), however, significantly inhibited the in vitro growth of HCC cells (P < 0.001). In an orthotopic model of HCC in nude mice, HAb18 and LICARTIN treatment effectively reduced the tumor growth and metastasis as well as the expression of three major factors in the HCC microenviroment (MMPs, vascular endothelial growth factor, and fibroblast surface protein) in the paracancer tissues. Overall, these results suggest that HAb18G/CD147 plays an important role in HCC invasion and metastasis mainly via modulating fibroblasts, as well as HCC cells themselves to disrupt the HCC microenviroment. LICARTIN can be used as a drug targeting to HAb18G/ CD147 in antimetastasis and recurrence therapy of HCC.

Purpose: Esophageal adenocarcinoma is a highly aggressive malignancy that frequently develops from Barrett's esophagus, a premalignant pathologic change occurring in the lower end of the esophagus. Identifying Barrett's esophagus patients at high risk of malignant transformation is essential to the prevention of esophageal adenocarcinoma. Although microRNA (miRNA) expression signatures have been associated with the etiology and prognosis of several types of cancers, their roles in the development of esophageal adenocarcinoma have not been extensively evaluated. Experimental Design: In this study, we analyzed the expression patterns of 470 human miRNAs using Agilent miRNA microarray in 32 disease/normal-paired tissues from 16 patients diagnosed with Barrett's esophagus of either low-or high-grade dysplasia, or esophageal adenocarcinoma. Results: Using unsupervised hierarchical clustering and class comparison analyses, we found that miRNA expression profiles in tissues of Barrett's esophagus with high-grade dysplasia were significantly different from their corresponding normal tissues. Similar findings were observed for esophageal adenocarcinoma, but not for Barrett's esophagus with low-grade dysplasia. The expression patterns of selected miRNAs were further validated using quantitative reverse transcription real-time PCR in an independent set of 75 pairs of disease/normal tissues. Finally, we identified several miRNAs that were involved in the progressions from low grade-dysplasia Barrett's esophagus to esophageal adenocarcinoma. Conclusions: We showed that miRNAs were involved in the development and progression of esophageal adenocarcinoma. The identified significant miRNAs that may become potential targets for early detection, chemoprevention, and treatment of esophageal cancer. (Clin Cancer Res 2009;15(18):5744-52)