Lung metastasis of pancreatic carcinoma is regulated by TGFβ signaling

Periostin induces epithelial‑to‑mesenchymal transition via the integrin α5β1/TWIST‑2 axis in cholangiocarcinoma

Periostin (PN) (also known as osteoblast-specific factor OSF-2) is a protein that in humans is encoded by the POSTN gene and has been correlated with a reduced survival of cholangiocarcinoma (CCA) patients, with the well-known effect of inducing epithelial-to-mesenchymal transition (EMT). The present study investigated the effect of PN, through integrin (ITG)α5β1, in EMT-mediated CCA aggressiveness. The alterations in EMT-related gene and protein expression were investigated by real-time PCR, western blot analysis and zymogram. The effects of PN on migration and the level of TWIST-2 were assessed in CCA cells with and without siITGα5 transfection. PN was found to induce CCA cell migration and EMT features, including increments in Twist-related protein 2 (TWIST-2), zinc finger protein SNAI1 (SNAIL-1), α-smooth muscle actin (ASMA), vimentin (VIM) and matrix metallopeptidase 9 (MMP-9), and a reduction in cytokeratin 19 (CK-19) together with cytoplasmic translocation of E-cadherin (CDH-1). Additionally, PN markedly induced MMP-9 activity. TWIST-2 was significantly induced in PN-treated CCA cells; this effect was attenuated in the ITGα5β1-knockdown cells and corresponded to reduced migration of the cancer cells. These results indicated that PN induced CCA migration through ITGα5β1/TWIST-2-mediated EMT. Moreover, clinical samples from CCA patients showed that higher levels of TWIST-2 were significantly correlated with shorter survival time. In conclusion, the ITGα5β1-mediated TWIST-2 signaling pathway regulates PN-induced EMT in CCA progression, and TWIST-2 is a prognostic marker of poor survival in CCA patients.

ITGA1 is a pre-malignant biomarker that promotes therapy resistance and metastatic potential in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) has single-digit 5-year survival rates at <7%. There is a dire need to improve pre-malignant detection methods and identify new therapeutic targets for abrogating PDAC progression. To this end, we mined our previously published pseudopodium-enriched (PDE) protein/phosphoprotein datasets to identify novel PDAC-specific biomarkers and/or therapeutic targets. We discovered that integrin alpha 1 (ITGA1) is frequently upregulated in pancreatic cancers and associated precursor lesions. Expression of ITGA1-specific collagens within the pancreatic cancer microenvironment significantly correlates with indicators of poor patient prognosis, and depleting ITGA1 from PDAC cells revealed that it is required for collagen-induced tumorigenic potential. Notably, collagen/ITGA1 signaling promotes the survival of ALDH1-positive stem-like cells and cooperates with TGFβ to drive gemcitabine resistance. Finally, we report that ITGA1 is required for TGFβ/collagen-induced EMT and metastasis. Our data suggest that ITGA1 is a new diagnostic biomarker and target that can be leveraged to improve patient outcomes.

Long non-coding RNA HOTAIR functions as miRNA sponge to promote the epithelial to mesenchymal transition in esophageal cancer

BACKGROUND

Accumulating evidence indicates dysregulated expression of the long non-coding RNA HOTAIR (lncRNA-HOTAIR) may play a significant role in tumor progression. LncRNA-HOTAIR promotes several processes in esophageal cancer (EC), including cell growth, differentiation, invasion and migration. However, the mechanisms by which lncRNA-HOTAIR promotes invasion and migration EC remain unclear.

METHODS

LncRNA-HOTAIR and miR-148a expression were quantified in 40 paired human EC and tumor-adjacent tissues and EC cell lines by quantitative real-time PCR (qRT-PCR). The CCK8 assay was used to quantify cell proliferation. Transwell invasion and migration assays were performed to assess cell invasion and migration. Western blot analysis was used to quantify E-cadherin, N-cadherin, Vimentin, and Snail2 expression. StarBase V2.0 was used to identify putative miRNA binding sites in lncRNA-HOTAIR; luciferase reporter assays were performed to validate the function of the predicted binding sites.

RESULT

High lncRNA-HOTAIR expression was associated with significantly poorer overall survival in EC. In vitro analysis showed lncRNA-HOTAIR enhanced EC cell proliferation, invasion and migration, and promoted the EMT. Mechanistic investigations revealed lncRNA-HOTAIR promotes the EMT by acting as a miR-148a sponge to positively regulate Snail2 expression.

CONCLUSIONS

LncRNA-HOTAIR acts as a miR-148a sponge to positively regulate Snail2 expression, enhance cell invasion and metastasis, and promote the EMT in EC. LncRNA-HOTAIR may play an important role in tumor development and progression and represent a novel therapeutic target for EC.

An Automated High-throughput Array Microscope for Cancer Cell Mechanics

Changes in cellular mechanical properties correlate with the progression of metastatic cancer along the epithelial-to-mesenchymal transition (EMT). Few high-throughput methodologies exist that measure cell compliance, which can be used to understand the impact of genetic alterations or to screen the efficacy of chemotherapeutic agents. We have developed a novel array high-throughput microscope (AHTM) system that combines the convenience of the standard 96-well plate with the ability to image cultured cells and membrane-bound microbeads in twelve independently-focusing channels simultaneously, visiting all wells in eight steps. We use the AHTM and passive bead rheology techniques to determine the relative compliance of human pancreatic ductal epithelial (HPDE) cells, h-TERT transformed HPDE cells (HPNE), and four gain-of-function constructs related to EMT. The AHTM found HPNE, H-ras, Myr-AKT, and Bcl2 transfected cells more compliant relative to controls, consistent with parallel tests using atomic force microscopy and invasion assays, proving the AHTM capable of screening for changes in mechanical phenotype.

Isolated pulmonary metastases define a favorable subgroup in metastatic pancreatic cancer

PURPOSE

Liver metastasis represents the first site of dissemination in >80% of metastatic pancreatic cancer (PC) patients. Pulmonary metastasis as first site of dissemination in PC is a rare event and might define a biologically distinct subgroup in metastatic PC.

METHODS

Consecutive PC patients who were diagnosed or treated with isolated pulmonary metastases at our high-volume comprehensive cancer center were included in a prospectively maintained database between 2002 and 2015. Medical records and correlating computed tomography findings (CT) were retrospectively analyzed.

RESULTS

A total of 40 PC patients with isolated pulmonary metastases were identified. Pulmonary metastases represented disease recurrence after initial resection of PC in 22 patients and disease progression of locally advanced pancreatic cancer in 5 patients. 14 out of 27 PC patients (56%) had received chemoradiotherapy for localized disease prior to pulmonary metastasis. Data on 1st-line treatment for pulmonary metastases was available for 38 patients: most patients (71%) received a gemcitabine-based chemotherapy regimen, 5 patients (13%) received best supportive care. After a median follow-up of 37.3 months, median survival after diagnosis of pulmonary metastasis was estimated with 25.5 months (95% CI 19.1-31.8); a significantly improved survival after diagnosis of pulmonary metastasis was observed for patients with less than 10 lung metastases (31.3 vs 18.7 months, p = 0.003) and for an unilateral localization of lung involvement (31.3 vs 21.8 months, p = 0.03).

CONCLUSIONS

Our results suggest a favorable outcome of PC patients with isolated pulmonary metastases. Further research is warranted to elucidate the specific molecular characteristics of this rare subgroup.