Background

Malignant mesothelioma is an aggressive, treatment-resistant tumor arising from mesothelium of pleura, peritoneum and pericardium. Despite current combined regimen, its prognosis remains dismal, calling for more effective targeted therapies. We investigated whether aberrant Hh activation may play a role in mesothelioma.

Methods

SMO and SHH expression levels were analyzed in 46 mesothelioma tissue specimens with real-time RT-PCR, and correlation with survival was analyzed with univariate and multivariate Cox proportional hazards models, Kaplan-Meier survival curves, and the log-rank test. We also examined multiple mesothelioma cell lines for SMO expression and the effect of Hh inhibition by a specific SMO antagonist on cell proliferation by MTS assay.

Results

We observed strong correlation between higher SMO and SHH expression levels with poorer overall survival. Remarkably, Hh inhibition by a specific SMO inhibitor significantly suppressed cell proliferation in the mesothelioma cell lines examined.

Conclusion

Our data strongly support that Hh signaling deregulation plays critical roles in proliferation of mesothelioma, and consistently exerts significant impact on prognosis of the disease. Therefore our findings revealed the hitherto unappreciated role of Hh activation in mesothelioma, and pinpointed Hh signaling antagonist as a potential new therapy against this devastating disease.

Abstract Background Malignant mesothelioma is an aggressive, treatment-resistant tumor arising from mesothelium of pleura, peritoneum and pericardium. Despite current combined regimen, its prognosis remains dismal, calling for more effective targeted therapies. We investigated whether aberrant Hh activation may play a role in mesothelioma. Methods SMO and SHH expression levels were analyzed in 46 mesothelioma tissue specimens with real-time RT-PCR, and correlation with survival was analyzed with univariate and multivariate Cox proportional hazards models, Kaplan-Meier survival curves, and the log-rank test. We also examined multiple mesothelioma cell lines for SMO expression and the effect of Hh inhibition by a specific SMO antagonist on cell proliferation by MTS assay. Results We observed strong correlation between higher SMO and SHH expression levels with poorer overall survival. Remarkably, Hh inhibition by a specific SMO inhibitor significantly suppressed cell proliferation in the mesothelioma cell lines examined. Conclusion Our data strongly support that Hh signaling deregulation plays critical roles in proliferation of mesothelioma, and consistently exerts significant impact on prognosis of the disease. Therefore our findings revealed the hitherto unappreciated role of Hh activation in mesothelioma, and pinpointed Hh signaling antagonist as a potential new therapy against this devastating disease.

The mechanism of Sonic Hedgehog (Shh) pathway activation in non-small cell lung cancer (NSCLC) is poorly described. Using an antibody against the Shh C-terminal domain, we found a small population of Shh-positive (Shh+) cells in NSCLC cells. The objective of this study was to characterize these Shh+ cells. Shh+ and Shh- cells were sorted by using Fluorescence Activated Cell Sorting (FACS) on 12 commercial NSCLC cell lines. Functional analyses on sorted cells were performed with gene expression assays (qRT-PCR and microarray) and cells were treated with cytotoxic chemotherapy and a targeted inhibitor of Shh signaling (GDC0449). We used in vivo models of nude mice inoculated with Shh+ and Shh- sorted cells and drug-treated cells. Finally, we confirmed our results in fresh human NSCLC samples (n=48) paired with normal lung tissue. We found that Shh+ cells produced an uncleaved, full-length Shh protein detected on the membranes of these cells. Shh+ cells exerted a paracrine effect on Shh- cells, inducing their proliferation and migration. Shh+ cells were chemo-resistant and showed features of cancer stem cells (CSCs) in vitro and in vivo. Pharmacological inhibition of the Shh pathway suppressed their CSC features. A high percentage of Shh+ cells was associated with poor prognosis in early-stage NSCLC patients. In conclusion, we describe for the first time the presence of an abnormal membrane-bound full-length Shh protein in human cancer cells that allows the identification of CSCs in vitro and in vivo.

Adenocarcinoma is the most common type of lung cancer. Epithelial-mesenchymal transition (EMT) is required for tumor invasion/metastasis and the components that control this process are potential therapeutic targets. This study we examined the role of Gli in lung adenocarcinoma and whether its activation regulates metastasis through EMT in lung adenocarcinoma. We found that tumors with high Gli expression had significantly lower E-Cadherin expression in two independent cohorts of patients with lung adenocarcinoma that we studied. In vitro up-regulation of SHh resulted in increased cell migration while small molecule inhibitors of Smo or Gli significantly reduced cell mobility both in a wound healing assay and in a 3D cell invasion assay. Inhibition of Gli in vivo decreased tumor growth and induced an increase in E-Cadherin expression. Our results indicate that Gli may be critical for lung adenocarcinoma metastasis and that a novel Gli inhibitor shows promise as a therapeutic agent by preventing cell migration and invasion in vitro and significantly reducing tumor growth and increasing E-Cadherin expression in vivo.

Background

To evaluate the safety and tolerability of docetaxel/carboplatin regimen in the post-operative setting of patients with non-small cell lung cancer (NSCLC).

Methods

Enrolment of 133 patients with stage Ib - IIIa NSCLC was undertaken in an open-label, single arm study to assess the safety and tolerability of docetaxel (75 mg/kg) and carboplatin (AUC 5.5) administered for 3 cycles after resection for curative intent. The primary endpoint of the study was safety, as reflected by a febrile neutropenia rate of <10%. Other endpoints assessed protocol compliance and the impact of minimally invasive surgical technique.

Results

Patient accrual was completed at 1 center in the US and 10 centers in China in <6 months. Febrile neutropenia complicated treatment in 12 patients (9.0%), below the predetermined safety threshold of 14 patients. Four VATS and 8 open thoracotomy patients experienced febrile neutropenia (P=0.26). Completion of the three-cycle adjuvant regimen was achieved in 86% (95% CI, 77-95%) of patients. Sixty-two of 66 VATS patients compared to 53 of 67 open thoracotomy patients received all three doses according to protocol (P<0.01). Thirteen serious adverse events (9.8%) and no deaths were attributed to the study regimen.

Conclusions

In this rapidly accrued study, docetaxel and carboplatin were well-tolerated in the adjuvant treatment of NSCLC. Adjuvant treatment compliance was higher among patients undergoing a minimally invasive surgical approach. (ClinicalTrials.gov number NCT00883675).

Coronavirus disease 2019 (COVID-19), the global pandemic caused by SARS-CoV-2, has resulted thus far in greater than 933,000 deaths worldwide; yet disease pathogenesis remains unclear. Clinical and immunological features of patients with COVID-19 have highlighted a potential role for changes in immune activity in regulating disease severity. However, little is known about the responses in human lung tissue, the primary site of infection. Here we show that pathways related to neutrophil activation and pulmonary fibrosis are among the major up-regulated transcriptional signatures in lung tissue obtained from patients who died of COVID-19 in Wuhan, China. Strikingly, the viral burden was low in all samples, which suggests that the patient deaths may be related to the host response rather than an active fulminant infection. Examination of the colonic transcriptome of these patients suggested that SARS-CoV-2 impacted host responses even at a site with no obvious pathogenesis. Further proteomics analysis validated our transcriptome findings and identified several key proteins, such as the SARS-CoV-2 entry-associated protease cathepsins B and L and the inflammatory response modulator S100A8/A9, that are highly expressed in fatal cases, revealing potential drug targets for COVID-19.

Viral infections can alter host transcriptomes by manipulating host splicing machinery. Despite intensive transcriptomic studies on SARS-CoV-2, a systematic analysis of alternative splicing (AS) in severe COVID-19 patients remains largely elusive. Here we integrated proteomic and transcriptomic sequencing data to study AS changes in COVID-19 patients. We discovered that RNA splicing is among the major down-regulated proteomic signatures in COVID-19 patients. The transcriptome analysis showed that SARS-CoV-2 infection induces widespread dysregulation of transcript usage and expression, affecting blood coagulation, neutrophil activation, and cytokine production. Notably, CD74 and LRRFIP1 had increased skipping of an exon in COVID-19 patients that disrupts a functional domain, which correlated with reduced antiviral immunity. Furthermore, the dysregulation of transcripts was strongly correlated with clinical severity of COVID-19, and splice-variants may contribute to unexpected therapeutic activity. In summary, our data highlight that a better understanding of the AS landscape may aid in COVID-19 diagnosis and therapy.