Ascending the PEAK1 toward targeting TGFβ during cancer progression: Recent advances and future perspectives

DHPS-dependent hypusination of eIF5A1/2 is necessary for TGFβ/fibronectin-induced breast cancer metastasis and associates with prognostically unfavorable genomic alterations in TP53

Metastasis is the leading cause of mortality in patients with solid tumors. In this regard, we previously reported that Pseudopodium-Enriched Atypical Kinase One (PEAK1) is necessary for non-canonical Transforming Growth Factor β (TGFβ) signaling and TGFβ/fibronectin-induced metastasis. Here, we demonstrate that inhibition of DHPS-dependent eIF5A1/2 hypusination blocks PEAK1 and E-Cadherin expression, breast cancer cell viability and TGFβ/fibronectin-induced PEAK1-dependent breast cancer metastasis. Interestingly, TGFβ stimulation of high-grade metastatic breast cancer cells increases and sustains eIF5A1/2 hypusination. We used a suite of bioinformatics platforms to search biochemical/functional interactions and clinical databases for additional control points in eIF5A1/2 and PEAK1-Epithelial to Mesenchymal Transition (EPE) pathways. This effort revealed that interacting EPE genes were enriched for TP53 transcriptional targets and were commonly co-amplified in breast cancer patients harboring inactivating TP53 mutations. Taken together, these results suggest that combinatorial therapies targeting DHPS and protein activities elevated in TP53-mutant breast cancers may reduce systemic tumor burden and improve patient outcomes.

Multi-modality imaging features distinguish pancreatic carcinoma from mass-forming chronic pancreatitis of the pancreatic head

The present study retrospectively analyzed computerized tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography-computerized tomography (PET/CT) data to identify features that may distinguish pancreatic carcinoma (PC) from mass-forming chronic pancreatitis (MFCP) of the pancreatic head. The mean diameter of the lesions was larger in the MFCP patients (n=24) than in the PC patients (n=30; 5.44±27 vs. 3.34±1.23 cm; P<0.001). PC lesions showed increased lobulation when compared with the MFCP cases (83.33 vs. 12.5%; P<0.001). Lesions in the MFCP patients exhibited diffuse and marginally distributed calcification. MFCP patients showed increased exudation around the lesion (83.33 vs. 13.33%), pseudocyst formation (58.33 vs. 10%) and thickening of the right renal fascia (83.33 vs. 13.33%) than in the PC patients. MFCP patients also exhibited visible remnants of normal pancreatic tissue within the lesions. MFCP and PC patients could be distinguished by a cutoff value of 4.40 cm for lesion size [area under the curve (AUC): 0.894; 95% confidence interval (CI): 0.810-0.978)], 21.85 Hu for net-increased value in the arterial phase (AUC, 0.799; 95% CI, 0.670-0.928), 37.70 Hu for net-increased value in the portal phase (AUC, 0.798; 95% CI, 0.919-0.677), 4.85 for early standardized uptake value (SUV) of 18F-deoxyglucose (18F-FDG; AUC, 0.934; 95% CI, 0.850-1.018) and 4.90 for delayed SUV of 18F-FDG (AUC, 0.958; 95% CI, 0.878-1.038). These findings demonstrated that the integration of data from dynamic contrast-enhanced CT, MRI and PET/CT imaging may distinguish MFCP from PC.

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.