An integrated multiomics analysis of rectal cancer patients identified POU2F3 as a putative druggable target and entinostat as a cytotoxic enhancer of 5-fluorouracil.

Rectal cancer (RC) accounts for one-third of colorectal cancers (CRC), and 40% of these are locally advanced rectal cancers (LARC). The use of neoadjuvant chemoradiotherapy (nCRT) significantly reduces the rate of local recurrence compared to adjuvant therapy or surgery alone. However, after nCRT, up to 40%-60% of patients show a poor pathological response, while only about 20% achieve a pathological complete response. In this scenario, the identification of novel predictors of tumor response to nCRT is urgently needed to reduce LARC mortality and to spare poorly responding patients from unnecessary treatments. Therefore, by combining gene and microRNA expression datasets with proteomic data from LARC patients, we developed an integrated network centered on seven hub-genes putatively involved in the response to nCRT. In an independent validation cohort of LARC patients, we confirmed that differential expression of NFKB1, TRAF6 and STAT3 is correlated with the response to nCRT. In addition, the functional enrichment analysis also revealed that these genes are strongly related to hallmarks of cancer and inflammation, whose dysfunction may causatively affect LARC patient's response to nCRT. Furthermore, by constructing the transcription factor-module network, we hypothesized a protective role of POU2F3 gene, which could be used as a new drug target in LARC patients. Finally, we identified and tested in vitro entinostat, a histone deacetylase inhibitor, as a chemical compound that could be combined with a classical therapeutic regimen in order to design more efficient therapeutic strategies in LARC management.

Doxorubicin treatment modulates chemoresistance and affects the cell cycle in two canine mammary tumour cell lines.

BACKGROUND: Doxorubicin (DOX) is widely used in both human and veterinary oncology although the onset of multidrug resistance (MDR) in neoplastic cells often leads to chemotherapy failure. Better understanding of the cellular mechanisms that circumvent chemotherapy efficacy is paramount. The aim of this study was to investigate the response of two canine mammary tumour cell lines, CIPp from a primary tumour and CIPm, from its lymph node metastasis, to exposure to EC50(20h) DOX at 12, 24 and 48 h of treatment. We assessed the uptake and subcellular distribution of DOX, the expression and function of P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP), two important MDR mediators. To better understand this phenomenon the effects of DOX on the cell cycle and Ki67 cell proliferation index and the expression of p53 and telomerase reverse transcriptase (TERT) were also evaluated by immunocytochemistry (ICC). RESULTS: Both cell lines were able to uptake DOX within the nucleus at 3 h treatment while at 48 h DOX was absent from the intracellular compartment (assessed by fluorescence microscope) in all the surviving cells. CIPm, originated from the metastatic tumour, were more efficient in extruding P-gp substrates. By ICC and qRT-PCR an overall increase in both P-gp and BCRP were observed at 48 h of EC50(20h) DOX treatment in both cell lines and were associated with a striking increase in the percentage of p53 and TERT expressing cells by ICC. The cell proliferation fraction was decreased at 48 h in both cell lines and cell cycle analysis showed a DOX-induced arrest in the S phase for CIPp, while CIPm had an increase in cellular death without arrest. Both cells lines were therefore composed by a fraction of cells sensible to DOX that underwent apoptosis/necrosis. CONCLUSIONS: DOX administration results in interlinked modifications in the cellular population including a substantial effect on the cell cycle, in particular arrest in the S phase for CIPp and the selection of a subpopulation of neoplastic cells bearing MDR phenotype characterized by P-gp and BCRP expression, TERT activation, p53 accumulation and decrease in the proliferating fraction. Important information is given for understanding the dynamic and mechanisms of the onset of drug resistance in a neoplastic cell population.

Establishment of a human 3D pancreatic adenocarcinoma model based on a patient-derived extracellular matrix scaffold.

Pancreatic cancer is likely to become one of the leading causes of cancer-related death in many countries within the next decade. Surgery is the potentially curative treatment for pancreatic ductal adenocarcinoma (PDAC), although only 10%-20% of patients have a resectable disease after diagnosis. Despite recent advances in curative surgery the current prognosis ranges from 6% to 10% globally. One of the main issues at the pre-clinical level is the lacking of model which simultaneously reflects the tumour microenvironment (TME) at both structural and cellular levels. Here we describe an innovative tissue engineering approach applied to PDAC starting from decellularized human biopsies in order to generate an organotypic 3D in vitro model. This in vitro 3D system recapitulates the ultrastructural environment of native tissue as demonstrated by histology, immunohistochemistry, immunofluorescence, mechanical analysis, and scanning electron microscopy. Mass spectrometry confirmed a different extracellular matrix (ECM) composition between decellularized healthy pancreas and PDAC by identifying a total of 110 non-redundant differently expressed proteins. Immunofluorescence analyses after 7 days of scaffold recellularization with PANC-1 and AsPC-1 pancreatic cell lines, were performed to assess the biocompatibility of 3D matrices to sustain engraftment, localization and infiltration. Finally, both PANC-1 and AsPC-1 cells cultured in 3D matrices showed a reduced response to treatment with FOLFIRINOX if compared to conventional bi-dimensional culture. Our 3D culture system with patient-derived tissue-specific decellularized ECM better recapitulates the pancreatic cancer microenvironment compared to conventional 2D culture conditions and represents a relevant approach for the study of pancreatic cancer response to chemotherapy agents.

The Study of the Extracellular Matrix in Chronic Inflammation: A Way to Prevent Cancer Initiation?

Bidirectional communication between cells and their microenvironment has a key function in normal tissue homeostasis, and in disease initiation, progression and a patient's prognosis, at the very least. The extracellular matrix (ECM), as an element of all tissues and cellular microenvironment, is a frequently overlooked component implicated in the pathogenesis and progression of several diseases. In the inflammatory microenvironment (IME), different alterations resulting from remodeling processes can affect ECM, progressively inducing cancer initiation and the passage toward a tumor microenvironment (TME). Indeed, it has been demonstrated that altered ECM components interact with a variety of surface receptors triggering intracellular signaling that affect cellular pathways in turn. This review aims to support the notion that the ECM and its alterations actively participate in the promotion of chronic inflammation and cancer initiation. In conclusion, some data obtained in cancer research with the employment of decellularized ECM (dECM) models are described. The reported results encourage the application of dECM models to investigate the short circuits contributing to the creation of distinct IME, thus representing a potential tool to avoid the progression toward a malignant lesion.