MicroRNA dysregulation in the tumor microenvironment influences the phenotype of pancreatic cancer

Challenges and innovations in CAR-T cell therapy: a comprehensive analysis

Recent years have seen a marked increase in research on chimeric antigen receptor T (CAR-T) cells, with specific relevance to the treatment of hematological malignancies. Here, the structural principles, iterative processes, and target selection of CAR-T cells for therapeutic applications are described in detail, as well as the challenges faced in the treatment of solid tumors and hematological malignancies. These challenges include insufficient infiltration of cells, off-target effects, cytokine release syndrome, and tumor lysis syndrome. In addition, directions in the iterative development of CAR-T cell therapy are discussed, including modifications of CAR-T cell structures, improvements in specificity using multi-targets and novel targets, the use of Boolean logic gates to minimize off-target effects and control toxicity, and the adoption of additional protection mechanisms to improve the durability of CAR-T cell treatment. This review provides ideas and strategies for the development of CAR-T cell therapy through an in-depth exploration of the underlying mechanisms of action of CAR-T cells and their potential for innovative modification.

miRNAs in pancreatic cancer progression and metastasis

Small non-coding RNA or microRNA (miRNA) are critical regulators of eukaryotic cells. Dysregulation of miRNA expression and function has been linked to a variety of diseases including cancer. They play a complex role in cancers, having both tumour suppressor and promoter properties. In addition, a single miRNA can be involved in regulating several mRNAs or many miRNAs can regulate a single mRNA, therefore assessing these roles is essential to a better understanding in cancer initiation and development. Pancreatic cancer is a leading cause of cancer death worldwide, in part due to the lack of diagnostic tools and limited treatment options. The most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC), is characterised by major genetic mutations that drive cancer initiation and progression. The regulation or interaction of miRNAs with these cancer driving mutations suggests a strong link between the two. Understanding this link between miRNA and PDAC progression may give rise to novel treatments or diagnostic tools. This review summarises the role of miRNAs in PDAC, the downstream signalling pathways that they play a role in, how these are being used and studied as therapeutic targets as well as prognostic/diagnostic tools to improve the clinical outcome of PDAC.

Knockdown of miR-24 Suppressed the Tumor Growth of Cervical Carcinoma Through Regulating PTEN/PI3K/AKT Signaling Pathway

Cervical cancer (CC) is the most prevalent malignant tumor in gynecology. Despite routine surgery, advanced CC is hard to remove completely. MicroRNA-24 (miR-24) regulates several types of tumors, but its regulatory function in CC was previously unknown. We established stable knockdown of miR-24 and phosphatase and tensin homolog (PTEN) in CC cells. We measured mRNA and protein expression with RT-PCR and western blotting. We evaluated cell proliferation, invasion, migration, and apoptosis with CCK8, Transwell, wound healing, and flow cytometry, respectively. We also examined the influence of miR-24 and PTEN on tumor growth in a metastatic tumor model in nude mice. The expression of miR-24 was significantly increased in CC tissues and cell lines (C-33A, HeLa S3, SiHa). MiR-24 inhibitor greatly suppressed PTEN/PI3K/AKT, while miR-24 mimic markedly activated this signaling pathway. Knockdown of PTEN significantly reversed the effects of miR-24 inhibitor on cell proliferation, invasion, migration, and apoptosis of CC cells. The significant inhibition effect of tumor growth and ki67 expression caused by miR-24 inhibitor was reversed by si-PTEN. MiR-24 inhibitor significantly suppressed cell proliferation, invasion, migration, epithelial-mesenchymal transition (EMT) process, and tumor growth, while promoting cell apoptosis. However, the influence of miR-24 inhibitor was markedly reversed by si-PTEN. Targeting miR-24 could provide a novel therapeutic strategy for the prevention and treatment of CC.

Invasive features of superficial oesophageal squamous cell carcinoma-analysis of risk factors for lymph node metastasis

There are currently no studies that have examined the clinicopathological factors in detail, including the histological images of the invasive front, and the risk of lymph node metastasis (LNM) in superficial oesophageal squamous cell carcinoma (SESCC). This study aimed to develop an algorithm that contributes to a better assessment of the risk of LNM and recurrence in SESCC. Clinicopathological factors, such as submucosal (SM) invasion distance, were examined in 88 surgically resected cases of SESCC. An SM invasion distance of 600 μm was the statistically best customer value for LNM (p = 0.0043). To obtain a histological image of the invasive front, we evaluated modified tumour budding (MBD) by modifying the number of tumour foci constituent cells and foci in tumour budding. We also evaluated the smallest number of tumour foci. Using these factors, we developed an algorithm to predict the risk of LNM. The best algorithm was created using an SM invasion distance of 600 μm and an index of 5 or more foci consisting of five or fewer tumour cells in the MBD (MBD5 high-grade ≥ 5), which was also significantly associated with recurrence-free survival (p = 0.0305). Further study of the algorithm presented in this study is expected to improve the quality of life of patients by selecting appropriate additional treatments after endoscopic resection and appropriate initial treatment for SESCC.

Increased Levels of miR-15b-5p and miR-20b-5p in Pancreatic Ductal Adenocarcinoma with Hepatic Metastases

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal forms of cancer. The symptoms appear in advanced stages, and diagnostic and prognostic tests for the early detection of PDAC and disease evolution are not available. The dysregulation of microRNAs (miRNAs) has been associated with cancer development and progression, and some miRNAs have been reported to promote specific metastasis. In this study we aimed to identify the miRNAs dysregulated in PDAC tumoral tissues and a subset of miRNAs associated with tumoral characteristics, mainly metastasis presence and site. For this, the expression of 84 miRNAs was evaluated by qPCR in 30 tumoral tissues and 16 samples of non-tumoral pancreatic tissues. The comparison revealed 32 dysregulated miRNAs (19 upregulated and 13 downregulated) in the PDAC group. Reactome pathway over-representation analysis revealed that these miRNAs are involved in several biological pathways, including "ESR-mediated signaling", "PIP3 activates AKT signaling", and "Regulation of PTEN", among others. Moreover, our study identified an upregulation of miR-15b-5p and miR-20b-5p in the tumoral tissues of patients with hepatic metastasis, outlining these miRNAs as potential markers for hepatic metastasis. No significant difference in miRNA expression was observed in relation to anatomic location, lymphovascular invasion, lung metastasis, and the presence of diabetes.

Analyzing the invasive front of colorectal cancer - By punching tissue block or laser capture microdissection?

The aim of this study was to determine the advantages and limitations of two commonly used sampling techniques, i.e., punching tissue block (PTB) and laser capture microdissection (LCM) when investigating tumor cell-derived gene expression patterns at the invasive front of colorectal cancer (CRC). We obtained samples from 20 surgically removed CRCs at locations crucial for tumor progression, i.e., the central part, the expansive front and the infiltrative front exhibiting tumor budding (TB), using both sampling techniques. At each location, we separately analyzed the expressions of miR-200 family (miR-141, miR-200a, miR-200b, miR-200c and miR-429), known as reliable markers of epithelial-mesenchymal transition (EMT). We found significant downregulation of all members of miR-200 family at the infiltrative front in comparison to the central part regardless of the used sampling technique. However, when comparing miR-200 expression between the expansive and the infiltrative front, we found significant downregulation of all tested miR-200 at the infiltrative front only in samples obtained by LCM. Our results suggest that, PTB is an adequate technique for studying the differences in tumor gene expression between the central part and the invasive front of CRC, but is insufficient to analyze and compare morphologically distinct patterns along the invasive front including TB. For this purpose, the use of LCM is essential.

Tumor budding as a potential prognostic marker in determining the behavior of primary liver cancers

Hepatocellular (HCC) and intrahepatic cholangiocarcinoma (ICC), the most common primary tumors of the liver, are among the most important causes of cancer deaths worldwide. Because patients with primary liver tumors are frequently diagnosed at an advanced stage and have high mortality, many efforts have been made to identify new markers to determine their behavior and treatment, similar to those in other solid organ tumors. Recently, morphological assessment of tumor budding (TB) has been revealed as a promising prognostic finding to predict tumor behavior and survival across several different tumor types. Currently, the TB score in colorectal cancer has been revealed as an important parameter in pathology report protocols to determine the course of the disease. Regarding the liver, despite enormous data showing that many mechanisms involved in TB are associated with tumor behavior in both HCC and ICC, studies focusing on the role of TB in predicting the behavior and prognosis of these tumors have started to be investigated very recently. The purpose of this review is to present data about TB in primary tumors of the liver, pointing out the potential role of this parameter in determining the course of the disease, and emphasize the need to increase the number of further studies focusing on the evaluation of this parameter with an overview of the mechanisms involved in TB.

microRNA-26a represses pancreatic cancer cell malignant behaviors by targeting E2F7

Dysregulation of microRNAs (miRNAs) exerts key roles in the development of pancreatic cancer (PCa). miR-26a is reportedly a tumor suppressor in cancers. However, whether miR-26a modulates PCa progression is poorly understood. Here, we found that miR-26a was down-regulated in PCa. Overexpressed miR-26a suppressed PCa cell proliferation, colony formation, and tumor stem cell properties. Mechanically, the transcription factor E2F7 is a downstream target of miR-26a. miR-26a decreased E2F7 expression through binding to the 3'-untranslated region (UTR) of E2F7. Decreased miR-26a in PCa tissues was inversely correlated with E2F7. The inhibitory effects of miR-26a in PCa were reversed by E2F7 overexpression. Consistently, the knockout of E2F7 further significantly inhibited the growth of PCa cells combined with miR-26a overexpression. Further study revealed that E2F7 bound the promoter of vascular endothelial growth factor A (VEGFA), a key factor in angiogenesis, and transcriptionally activated the expression of VEGFA. miR-26a overexpression attenuated the effects of E2F7 on VEGFA promotion. Our results uncovered the novel function of miR-26a/E2F7/VEGFA in PCa, making miR-26a a possible target for PCa treatment.

Evaluation of Diagnostic Potential of Epigenetically Deregulated MiRNAs in Epithelial Ovarian Cancer

Background

Epithelial ovarian cancer (EOC) is one of the most lethal gynecological malignancies among women worldwide. Early diagnosis of EOC could help in ovarian cancer management. MicroRNAs, a class of small non-coding RNA molecules, are known to be involved in post-transcriptional regulation of ~60% of human genes. Aberrantly expressed miRNAs associated with disease progression are confined in lipid or lipoprotein and secreted as extracellular miRNA in body fluid such as plasma, serum, and urine. MiRNAs are stably present in the circulation and recently have gained an importance to serve as a minimally invasive biomarker for early detection of epithelial ovarian cancer.

Methods

Genome-wide methylation pattern of six EOC and two normal ovarian tissue samples revealed differential methylation regions of miRNA gene promoter through MeDIP-NGS sequencing. Based on log2FC and p-value, three hypomethylated miRNAs (miR-205, miR-200c, and miR-141) known to have a potential role in ovarian cancer progression were selected for expression analysis through qRT-PCR. The expression of selected miRNAs was analyzed in 115 tissue (85 EOC, 30 normal) and 65 matched serum (51 EOC and 14 normal) samples.

Results

All three miRNAs (miR-205, miR-200c, and miR-141) showed significantly higher expression in both tissue and serum cohorts when compared with normal controls (p < 0.0001). The receiver operating characteristic curve analysis of miR-205, miR-200c, and miR-141 has area under the curve (AUC) values of 87.6 (p < 0.0001), 78.2 (p < 0.0001), and 86.0 (p < 0.0001), respectively; in advance-stage serum samples, however, ROC has AUC values of 88.1 (p < 0.0001), 78.9 (p < 0.0001), and 86.7 (p < 0.0001), respectively, in early-stage serum samples. The combined diagnostic potential of the three miRNAs in advance-stage serum samples and early-stage serum samples has AUC values of 95.9 (95% CI: 0.925-1.012; sensitivity = 96.6% and specificity = 80.0%) and 98.1 (95% CI: 0.941-1.021; sensitivity = 90.5% and specificity = 100%), respectively.

Conclusion

Our data correlate the epigenetic deregulation of the miRNA genes with their expression. In addition, the miRNA panel (miR-205 + miR-200c + miR-141) has a much higher AUC, sensitivity, and specificity to predict EOC at an early stage in both tissue and serum samples.

Integrated Analysis of mRNA-seq and miRNA-seq to Identify c-MYC, YAP1 and miR-3960 as Major Players in the Anticancer Effects of Caffeic Acid Phenethyl Ester in Human Small Cell Lung Cancer Cell Line

BACKGROUND

Caffeic Acid Phenethyl Ester (CAPE), an active extract of propolis, has recently been reported to have broad applications in various cancers. However, the effects of CAPE on Small Cell Lung Cancer (SCLC) are largely unknown. Therefore, the aim of this study was to determine the anti-proliferative effect of CAPE and explore the underlying molecular mechanisms in SCLC cells using high-throughput sequencing and bioinformatics analysis.

METHODS

Small-cell lung cancer H446 cells were treated with CAPE, and cell proliferation and apoptosis were then assessed. Additionally, the regulation mediated by miR-3960 after CAPE treatment was explored and the altered signaling pathways were predicted in a bioinformatics analysis.

RESULTS

CAPE significantly inhibited cell proliferation and induced apoptosis. CAPE decreased the expression of Yes-Associated Protein 1 (YAP1) and cellular myelocytomatosis oncogene (c-MYC) protein. Moreover, the upregulation of miR-3960 by CAPE contributed to CAPE-induced apoptosis. The knockdown of miR-3960 decreased the CAPE-induced apoptosis.

CONCLUSION

We demonstrated the anti-cancer effect of CAPE in human SCLC cells and studied the mechanism by acquiring a comprehensive transcriptome profile of CAPE-treated cells.

Drivers of Gene Expression Dysregulation in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) remains a devastating disease with a poor prognosis. The functional consequences of common genetic aberrations and their roles in treatment strategies have been extensively reviewed. In addition to these genomic aberrations, consideration of non-genetic drivers of altered oncogene expression is essential to account for the diversity in PDAC phenotypes. In this review we seek to assess our current understanding of mechanisms of gene expression dysregulation. We focus on four drivers of gene expression dysregulation, including mutations, transcription factors, epigenetic regulators, and RNA stability/isoform regulation, in the context of PDAC pathogenesis. Recent studies provide much-needed insight into the role of gene expression dysregulation in dissecting tumor heterogeneity and stratifying patients for the development of personalized treatment strategies.

MicroRNA-363-3p inhibits tumor cell proliferation and invasion in oral squamous cell carcinoma cell lines by targeting SSFA2

The aim of the present study was to evaluate the expression levels of microRNA (miR)-363-3p and its underlying physiological function in oral squamous cell carcinoma (OSCC). miR-363-3p expression levels were measured in OSCC cell lines using reverse transcription-quantitative PCR. The role of miR-363-3p in OSCC cells was examined using gain-of-function assays in vitro. Cell proliferation was assessed using Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine assays and flow cytometry. Cell migration and invasion were evaluated in wound-healing and Transwell Matrigel assays. In addition, bioinformatics analysis predicted binding sites of miR-363-3p on sperm-specific antigen 2 (SSFA2). Luciferase reporter and RNA pull-down assays were conducted to test whether miR-363-3p interacted with SSFA2. miR-363-3p expression was downregulated in OSCC cell lines compared with that in the normal epithelial cell line (NHOK). Additionally, miR-363-3p overexpression suppressed OSCC cell proliferation, migration and invasion in vitro. SSFA2 was verified as a direct target of miR-363-3p, and SSFA2 overexpression partially counteracted the inhibitory effects of miR-363-3p on cell proliferation, migration and invasion in OSCC cell lines. Thus, miR-363-3p may serve as a tumor suppressor via targeting SSFA2 and may represent a potential therapeutic target for OSCC.

MiR-4269 suppresses the tumorigenesis and development of pancreatic cancer by targeting ZEB1/OTX1 pathway

As one of the most prevalent malignant tumors, pancreatic cancer (PC) is a leading fatal cancer worldwide. Surging evidence has unraveled that miRNAs are involved in the occurrence and progression of multiple cancers, including PC. The tumor suppressor effects of miR-4269 have been certified in gastric carcinoma. However, the potential function of miR-4269 remains largely unclear, which drives us to identify the role of miR-4269 in PC development. In the present study, we determined the expression pattern of miR-4269 in PC cells and normal cells. Results of RT-qPCR analysis illuminated that miR-4269 expression level in PC cells was lower than that in normal cells. Functional assays demonstrated that up-regulation of miR-4269 obviously inhibited the proliferation, migration and invasion of PC cells. In order to elucidate the mechanism governing miR-4269 in PC, we carried out bioinformatics analysis and further experimental investigations. Our results validated that ZEB1 was a direct target of miR-4269. Additionally, ZEB1 activated the transcription of OXT1. More importantly, miR-4269 attenuated the expression level of OXT1 via targeting ZEB1. Ultimately, our findings confirmed that miR-4269 served as a cancer suppressor in PC through regulation of ZEB1/OTX1 pathway, which suggested that miR-4269 might represent a promising target for the clinical treatment of PC.

MicroRNA-217: A regulator of human cancer

As highly conserved non-coding RNAs of approximately 18-24 nucleotides, microRNAs (miRNAs) regulate the expression of target genes. Multiple studies have demonstrated that miRNAs participate in the regulation of human cancer. MircoRNA-217 (miR-217) participates in the regulation of various tumors by specifically binding target genes and post-transcriptional regulation. In recent years, there have been numerous reports about miR-217 in tumor progression. MiR-217 is known mainly as a tumor suppressor, although some studies have shown that it functions as an oncomiR. Here, we review the current research related to miR-217, including its role in tumor progression and the molecular mechanisms.

Tumour budding in solid cancers

Tumour budding is an emerging prognostic biomarker in colorectal cancer (CRC) and other solid cancers. Tumour buds are usually defined as isolated single cancer cells or clusters of up to four cancer cells located at the invasive tumour front. The prognostic value of tumour budding is now supported by a large body of evidence, whereas the utility of this phenotype as a predictive biomarker remains under investigation. The application of tumour budding indices in clinical practice requires a standardized scoring system that can be tailored to specific tumour types and clinical scenarios. In the context of CRC, tumour budding can be assessed according to the method agreed at the International Tumour Budding Consensus Conference (ITBCC) in 2016. Using the ITBCC scoring system, tumour budding is an independent predictor of lymph node metastasis in patients with pT1 CRC and of unfavourable survival in patients with stage II colon cancer. Regardless of the clinical scenario or tumour type, the assertion that 'the more tumour buds, the worse the clinical outcome' applies. In this Review, we provide an overview of tumour budding in solid cancers, highlighting the molecular and biological aspects of this phenomenon, including its associations with epithelial-mesenchymal transition and features of the tumour microenvironment. We also describe the available evidence demonstrating the value of tumour budding as a biomarker across various solid cancers.

miR-205: A Potential Biomedicine for Cancer Therapy

microRNAs (miRNAs) are a class of small non-coding RNAs that regulate the expression of their target mRNAs post transcriptionally. miRNAs are known to regulate not just a gene but the whole gene network (signaling pathways). Accumulating evidence(s) suggests that miRNAs can work either as oncogenes or tumor suppressors, but some miRNAs have a dual nature since they can act as both. miRNA 205 (miR-205) is one such highly conserved miRNA that can act as both, oncomiRNA and tumor suppressor. However, most reports confirm its emerging role as a tumor suppressor in many cancers. This review focuses on the downregulated expression of miR-205 and discusses its dysregulation in breast, prostate, skin, liver, gliomas, pancreatic, colorectal and renal cancers. This review also confers its role in tumor initiation, progression, cell proliferation, epithelial to mesenchymal transition, and tumor metastasis. Restoration of miR-205 makes cells more sensitive to drug treatments and mitigates drug resistance. Additionally, the importance of miR-205 in chemosensitization and its utilization as potential biomedicine and nanotherapy is described. Together, this review research article sheds a light on its application as a diagnostic and therapeutic marker, and as a biomedicine in cancer.

Circular RNA ADAM9 facilitates the malignant behaviours of pancreatic cancer by sponging miR-217 and upregulating PRSS3 expression

Pancreatic cancer (PC) is a highly lethal human cancer. We previously found that Serine protease 3 (PRSS3), as an oncogene, is significantly upregulated in PC. In this study, we aimed to investigate the potential mechanism of PRSS3 dysregulation in PC. In this research, low miR-217 and high circ-ADAM9 expression were found in PC tissues and cell lines, which was closely associated with advanced clinical stage and lymph node metastasis. Patients with low miR-217 or high circ-ADAM9 expression had shorter survival time than those with high miR-217 or low circ-ADAM9 expression. Functionally, manipulation of miR-217 and circ-ADAM9 expression showed opposite effects on cell proliferation, migration and invasion. Stepwise mechanism studies indicated that circ-ADAM9 alleviated the inhibitory effect of miR-217 on PRSS3 by directly sponging miR-217 to increase the expression level of PRSS3, resulting in the activation of ERK/VEGF signalling pathway. In vivo, circ-ADAM9 silencing or miR-217 overexpression evidently retarded the growth of tumour, and the combination of them exhibited an additive inhibitory effect on tumourigenicity. Briefly, the ceRNA regulatory network of circ-ADAM9/miR-217/PRSS3 plays a pivotal role in PC progression by the regulation of ERK/VEGF signalling pathway.

Extracellular vesicles microRNA analysis in type 1 autoimmune pancreatitis: Increased expression of microRNA-21

BACKGROUND

The molecular basis of type 1 autoimmune pancreatitis (AIP) remains unclear. Recent attention on the role of extracellular vesicles microRNA (EV miRNA) in immune homeostasis has prompted us to perform an extensive miRNA screening of serum-derived EV in AIP.

METHODS

EV miRNA expression was analyzed using microarrays in AIP, chronic pancreatitis (CP), and healthy adult (HC) samples (n = 10 from each group). Differences in signals, > 3 or <1/3 times, represented significant differences in expression. Another cohort of AIP (n = 14), CP (n = 10), and HC (n = 10) samples of EV miRNA was analyzed using reverse-transcription polymerase chain reaction (RT-PCR). miRNA expression in pancreatic tissues was evaluated using in situ hybridization (ISH) in three additional subjects from each group.

RESULTS

Signals of eight miRNAs (miR-659-3p, -27a-3p, -99a-5p, -21-5p, -205-5p, -100-5p, -29c-3p, and -125b-1-3p) were significantly higher, while those of two miRNAs (miR-4252 and -5004-5p) were significantly lower in AIP than in HC. EV miR-21-5p was significantly up-regulated in AIP than in HC (P = 0.035) and CP (P = 0.048). The number of miR-21-5p positive inflammatory cells was significantly elevated in AIP than in CP (P = 0.014).

CONCLUSIONS

Circulating EVs exhibited altered miRNA expression patterns with elevated miR-21-5p in AIP when compared with those in HC and CP. miR-21-5p was highly expressed in pancreatic inflammatory cells in AIP. Our data suggests that miR-21-5p may be involved in the regulation of effector pathways in the pathophysiology of AIP, thus differentiating AIP from CP.

A microRNA-based signature predicts local-regional failure and overall survival after pancreatic cancer resection

Resectable pancreatic adenocarcinoma (PC) is generally managed with surgery followed by chemotherapy, but the role of postoperative chemoradiation (pCRT) is controversial. We sought to identify a microRNA (miRNA) expression profile associated with higher risk for local-regional recurrence (LRR), which might help identify patients that may benefit from pCRT. Total RNA was isolated from viable tumor from 88 patients who underwent PC resection with or without chemotherapy, but did not receive radiation. Digital miRNA expression profiling was performed and risk scores were calculated based on the expression levels of the four most significantly correlated miRNAs, and dichotomized about the median to detect correlations between risk group, LRR and overall survival (OS). Two cohorts from The Cancer Genome Atlas (TCGA) and Seoul National University (SNU) were used for validation. Patients with high-risk scores had significantly worse LRR (p = 0.001) and worse OS (p = 0.034). Two-year OS rates for the high- and low-risk groups were 27.7% and 52.2%, respectively. On multivariable analysis, the risk score remained significantly associated with LRR (p = 0.018). When validated on TCGA data, a high-risk score was associated with worse OS on univariate (p = 0.03) and multivariable analysis (p = 0.017). When validated on the SNU cohort, a high-risk score was likewise associated with worse OS (p = 0.042). We have developed a 4-miRNA molecular signature that is associated with risk of LRR and OS after PC resection and validated on two separate cohorts. This signature has the potential to select patients most likely to benefit from pCRT, and should be tested further.

Correlation between FAK and EGF-Induced EMT in Colorectal Cancer Cells

Epithelial-mesenchymal transition (EMT) plays an important role in the invasion and metastasis of colorectal cancer, which is mediated by FAK and EGF. However, whether FAK participates in EMT in colorectal cancer cells through the EGF/EGFR signaling pathway remains unknown. The aim of this study was to investigate the effector mechanisms of FAK in the process of EGF-induced EMT in colorectal cancer cells and to determine whether miR-217 is involved in this process. Caco-2 cancer cells were routinely cultured with and without treatment with 100 ng/mL EGF, and changes in cell morphology were observed using an inverted microscope. In addition, a transwell assay was used to detect cell migration under the condition of EGF treatment. The expression of FAK, pFAK, E-cadherin, vimentin, and β actin was assessed by western blotting, and the expression of miR-217 was assessed using real-time PCR. We found that EGF induced EMT in colorectal cancer cells and enhanced cell migration and invasion ability. Moreover, FAK was involved in the EGF-induced EMT of colorectal cancer cells. EGF upregulated the expression of E-cadherin in colorectal cancer cells by activating FAK, and miR-217 was found to participate in EGF-induced EMT in colorectal cancer cells. Our findings indicate that EGF induces EMT in colorectal cancer cells by activating FAK, and miR-217 is involved in the EGF/FAK/E-cadherin signaling pathway.

miRNAs as Influencers of Cell-Cell Communication in Tumor Microenvironment

microRNAs (miRNAs) are small noncoding RNAs that regulate gene expression at the posttranscriptional level, inducing the degradation of the target mRNA or translational repression. MiRNAs are involved in the control of a multiplicity of biological processes, and their absence or altered expression has been associated with a variety of human diseases, including cancer. Recently, extracellular miRNAs (ECmiRNAs) have been described as mediators of intercellular communication in multiple contexts, including tumor microenvironment. Cancer cells cooperate with stromal cells and elements of the extracellular matrix (ECM) to establish a comfortable niche to grow, to evade the immune system, and to expand. Within the tumor microenvironment, cells release ECmiRNAs and other factors in order to influence and hijack the physiological processes of surrounding cells, fostering tumor progression. Here, we discuss the role of miRNAs in the pathogenesis of multicomplex diseases, such as Alzheimer’s disease, obesity, and cancer, focusing on the contribution of both intracellular miRNAs, and of released ECmiRNAs in the establishment and development of cancer niche. We also review growing evidence suggesting the use of miRNAs as novel targets or potential tools for therapeutic applications.

MicroRNA-183 in Cancer Progression

MicroRNA-183(miR-183) is abnormally expressed in many kinds of tumors. It participates in the initiation and development of tumors. There are many pathways regulate the expression of miR-183. The action mechanism of miR-183 in cancer is very extensive, and contradictory conclusions are often drawn. It was upregulated in 18 kinds of cancer, downregulated in 6 kinds of cancer. In addition, there are seven types of cancer, both upregulated and downregulated reports can be found. Evidence showed that miR-183 can not only directly play the role of oncogene or antioncogene, but also regulate the expression of other oncogene or antioncogene in different cancer types. In this review, we discuss the regulator of miR-183 and summarized the expression of miR-183 in different cancers. We also counted the target genes of miR-183 and the functional roles they play. Furthermore, we focused on the roles of miR-183 in cell migration, cell invasion, epithelial-mesenchymal transition (EMT) and microangiogenesis, which play the most important roles in cancer processes. It sheds light on the likely reasons why miR-183 plays different roles in various cancers. In addition, miR-183 and its downstream effectors have the potential to be promising prognostic markers and therapeutic targets in cancer.

FOXC1 Regulation of miR-31-5p Confers Oxaliplatin Resistance by Targeting LATS2 in Colorectal Cancer

Colorectal cancer (CRC) is the second leading cause of cancer-related illness worldwide and one of the most common malignancies. Therefore, colorectal cancer research and cases have gained increasing attention. Oxaliplatin (OXA) is currently used in first-line chemotherapy to treat stage III and stage IV metastatic CRC. However, patients undergoing chemotherapy often develop resistance to chemo drugs being used. Evidence has confirmed that microRNAs regulate downstream genes in cancer biology and thereby have roles related to tumor growth, proliferation, invasion, angiogenesis, and multi-drug resistance. The aim of our study is to establish whether miR-31-5p is an oncogene in human colorectal cancers that are resistant to OXA and further confirm its malignant phenotype-associated target molecule. From the results of miRNA microarray assay, we establish that miR-31-5p expression was upregulated in oxaliplatin-resistant (OR)-LoVo cells compared with parental LoVo cells. Moreover, through in vitro and in vivo experiments, we demonstrate that miR-31-5p and large tumor suppressor kinase 2 (LATS2) were inversely related and that miR-31-5p and Forkhead box C1 (FOXC1) were positively correlated in the same LoVo or OR-LoVo cells. Importantly, we reveal a novel drug-resistance mechanism in which the transcription factor FOXC1 binds to the miR-31 promoter to increase the expression of miR31-5p and regulate LATS2 expression, resulting in cancer cell resistance to OXA. These results suggest that miR-31-5p may be a novel biomarker involved in drug resistance progression in CRC patients. Moreover, the FOXC1/miR31-5p/LATS2 drug-resistance mechanism provides new treatment strategies for CRC in clinical trials.

Role of non-coding RNA in pancreatic cancer

Pancreatic cancer is a malignant disease that develops rapidly and carries a poor prognosis. Currently, surgery is the only radical treatment. Non-coding RNAs (ncRNAs) are protein-free RNAs produced by genome transcription; they play important roles in regulating gene expression, participating in epigenetic modification, cell proliferation, differentiation and reproduction. ncRNAs also play key roles in the development of cancer; microRNA (miRNA) and long non-coding RNA (lncRNA) may lead the way to new treatments for pancreatic cancer. miRNAs are short-chain ncRNAs (19–24 nt) that inhibit the degradation of protein translation or their target gene mRNAs to regulate gene expression. lncRNAs contain >200 nt of ncRNA and play important regulatory roles in a number of malignant tumors, in terms of tumor cell proliferation, apoptosis, invasion and distant metastasis. lncRNAs can be exploited for the diagnosis and treatment of pancreatic cancer and have substantial prospects for clinical application. Nevertheless, the molecular mechanism of their regulation and function, as well as the significance of other ncRNAs, such as piwi-interacting RNA, in the pathogenesis of pancreatic cancer, are largely unknown. In this review, the structures of ncRNAs with various classifications, as well as the functions and important roles of ncRNAs in the diagnosis and treatment of pancreatic cancer are reviewed.

Clinical Scenarios Emerging from Combined Immunophenotypic, Molecular and Morphologic Analysis of Pancreatic Cancer: The Good, the Bad and the Ugly Scenario

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with increasing incidence and dismal prognosis. The composition of the immune cell infiltrates in the tumor microenvironment (TME) and the dynamic interplay between cancer- and immune cells can influence and/or be influenced by tumor-intrinsic characteristics like molecular profiles and tumor cell morphology. The combined analyses of pancreatic cancer by using morphologic, genetic, and immunologic features help us understand the significant heterogeneity of the TME and recognize the different mechanisms of immune evasion. Moreover, this information may lead to the identification of novel biomarkers for more precise patient stratification and therapy guidance.

Tumour microenvironment of pancreatic cancer: immune landscape is dictated by molecular and histopathological features

Pancreatic cancer is a lethal disease, with fewer than 7% of patients surviving beyond 5 years following diagnosis. Immune responses are known to influence tumour progression. The dynamic interaction between cancer cells and immune cells in the tumour microenvironment (TME) can not only result in, or be influenced by, different tumour characteristics, but it can also lead to diverse mechanisms of immune evasion. At present, there is much interest in classifying pancreatic cancer according to its morphologic, genetic and immunologic features in order to understand the significant heterogeneity of this tumour type. Such information can contribute to the identification of highly needed novel prognostic and predictive biomarkers, and can be used for accurate patient stratification and therapy guidance. This review focuses on the characteristics of the local immune contexture of pancreatic ductal adenocarcinoma and the interaction between tumour cells and immune cells within the TME, by simultaneously taking into account the histomorphologic and genetic features of the tumours. The emerging opportunities for approaches that could predict the most-effective therapeutic modalities towards more targeted, personalised treatments to improve patient care are also discussed.

Co-expression of cytokeratin and vimentin in colorectal cancer highlights a subset of tumor buds and an atypical cancer-associated stroma

Tumor buds in colorectal cancer are hypothesized to undergo a (partial) epithelial-mesenchymal transition (EMT). If so, cytokeratin (CK) and vimentin (VIM) co-expression is expected. CK+/VIM+ can also be found in some stromal cells; however, their origin remains unclear. Here, we determine the frequency of CK+/VIM+ tumor cells and characterize the CK+/VIM+ stroma in colorectal cancer. Three cell populations (CK+, VIM+, CK+/VIM+) were sorted using DepArray and fluorescence-activated cell sorting (FACS). Tumor areas were selected to include tumor center, stroma and tumor budding. Fluorescence microscopy was used to visualize co-expressing cells on whole slides. A next-generation tissue microarray (ngTMA) of matched Pan-CK-positive and -negative stroma was constructed and stained for E-cadherin, VIM, Snail1, Twist1, Zeb1 and Zeb2, COL11A1, SPARC, CD90, α-SMA, FAP and WT1. CK+/VIM+ co-expressing tumor cells were detected using all three methods. With DepArray, only tumor budding areas contained CK+/VIM+ cells. The proportion of CK+/VIM+ tumor cells was low (1.5%-22%). CK+ stroma was associated with aggressive tumor features like distant metastasis (P = .0003), lymphatic invasion (P = .0009) and tumor budding (P = .0084). CK+/VIM+ stroma was characterized by positive WT1 (P < .001), ZEB2 (P < .001), TWIST1 (P = .009), and FAP (P = .003). Our data suggest that CK+/VIM+ tumor cells exist, albeit in low numbers and could represent a subgroup of tumor buds in partial EMT. CK+/VIM+ stroma may be of mesothelial origin and shows features of mesenchymal cells and cancer-associated fibroblasts. These results, together with the association with metastasis point to cells in mesothelial-mesenchymal transition (MMT). This atypical stroma may be a potential target for therapy.

Cell Cycle Regulation of Stem Cells by MicroRNAs

MicroRNAs (miRNAs) are a class of small non-coding RNA molecules involved in the regulation of gene expression. They are involved in the fine-tuning of fundamental biological processes such as proliferation, differentiation, survival and apoptosis in many cell types. Emerging evidence suggests that miRNAs regulate critical pathways involved in stem cell function. Several miRNAs have been suggested to target transcripts that directly or indirectly coordinate the cell cycle progression of stem cells. Moreover, previous studies have shown that altered expression levels of miRNAs can contribute to pathological conditions, such as cancer, due to the loss of cell cycle regulation. However, the precise mechanism underlying miRNA-mediated regulation of cell cycle in stem cells is still incompletely understood. In this review, we discuss current knowledge of miRNAs regulatory role in cell cycle progression of stem cells. We describe how specific miRNAs may control cell cycle associated molecules and checkpoints in embryonic, somatic and cancer stem cells. We further outline how these miRNAs could be regulated to influence cell cycle progression in stem cells as a potential clinical application.

MiR-217 promotes cell proliferation and osteogenic differentiation of BMSCs by targeting DKK1 in steroid-associated osteonecrosis

MicroRNAs (miRNAs) have recently been recognized to play an important role in bone-associated diseases. This study aims to explore the expression profile and biological function of miR-217, which is known to be related to tumor cell proliferation and migration, to the proliferation and osteogenic differentiation of MSCs from the patients with steroid-associated osteonecrosis (ONFH). Bone marrow was obtained from the proximal femur of 10 patients with ONFH and 10 patients with femoral neck fractures. Bone marrow-derived mesenchymal stem cells (MSCs) were isolated and cultured. The expression profile, biological function of miR-217 and the interaction between miR-217 and DKK1 were assayed using cell viability measurement, western blot, Real-time PCR, luciferase reporter assay, Alizarin Red S (ARS) staining. We noted that the expression level of miR-217 was significantly decreased in the ONFH samples compared to the control samples (P < 0.0001). By targeting DKK1, miR-217 promoted nuclear translocation of β-catenin, increased expression of RUNX2, COL1A1 and obviously promoted the proliferation and differentiation of MSCs. Restoring the expression of DKK1 in the MSCs partially reversed the role of miR-217. These findings suggest that miR-217 promotes cell proliferation and osteogenic differentiation by inhibiting DKK1 during the development of steroid-associated osteonecrosis.

MALAT1 promotes the colorectal cancer malignancy by increasing DCP1A expression and miR203 downregulation

The long non-coding RNA MALAT1 has been proved to promote the cell proliferation, drug resistance, invasion, and metastasis of colorectal cancer (CRC) in vitro and in vivo by regulating the expression of various oncogenes and their protein products. Our previous work discovered that the expression of the mRNA-decapping enzymes 1a (DCP1A) is upregulated in CRCs. However, the relationships between MALAT1 and DCP1A in the development of CRC and the underlying mechanisms are still unclear. In this study, we investigated the molecular mechanisms by which MALAT1 and DCP1A may be linked to contribute to the malignancies of CRCs. We found that DCP1A is a direct target molecule of MALAT1. Moreover, by screening the downstream genes of MALAT1, we noticed that microRNA 203(miR203), an oncogene suppressor in numerous cancers, is inversely correlated to both MALAT1 and DCP1A expressions. Following MALAT1 knockdown, we observed overexpression of miR203 accompanied with DCP1A downregulation to a level that reversed the promoted cell proliferation, invasion, and migration in vitro and in vivo, which could be restored by miR203 knockdown or DCP1A overexpression. These results proposed a new molecular mechanism of MALAT-miR203-DCP1A axis which is involved with the development and contributes to the malignancy of colorectal cancers.

Tumor budding as a standardized parameter in gastrointestinal carcinomas: more than just the colon

Tumor budding, defined as single cells or clusters of less than five cells, is thought to be a histomorphologic marker of an aggressive tumor behavior mimicking the embryologic epithelial-mesenchymal transition, and has been well established in the past two decades as a poor prognostic factor in colorectal carcinoma. Slow uptake in routine reporting of this important pathologic prognostic feature was in part due to differing methods of assessment of budding reported in the literature, but has recently been clarified at a consensus conference on tumor budding in colorectal carcinoma. Tumor budding is also increasingly being reported as a useful pathologic prognostic feature in other gastrointestinal carcinomas, including esophageal squamous cell carcinoma and adenocarcinoma, gastric intestinal-type adenocarcinoma, pancreatic ductal adenocarcinoma, and ampullary adenocarcinoma. In this review, we will summarize the studies on tumor budding in gastrointestinal carcinomas, with a focus on the methods of assessment used and the potential clinical applications of the findings.

MicroRNA‑874 inhibits proliferation and invasion of pancreatic ductal adenocarcinoma cells by directly targeting paired box 6

Studies have demonstrated that a number of microRNAs (miRNAs) are dysregulated in pancreatic ductal adenocarcinoma (PDAC), and alterations in their expression may affect the onset and progression of PDAC. Therefore, the expression patterns, biological functions and associated molecular mechanisms of miRNAs in PDAC should be elucidated for the development of novel therapeutic methods. Previous studies reported significant miRNA‑874 (miR‑874) dysregulation in multiple types of human cancer. However, the expression pattern, possible roles and underlying mechanisms of miR‑874 in PDAC remain to be elucidated. This study evaluated miR‑874 expression in PDAC and examined its biological functions and underlying mechanism of action in PDAC progression. miR‑874 expression was downregulated in PDAC tissues and cell lines. Functional experiments demonstrated that upregulation of miR‑874 inhibited cell proliferation and invasion in PDAC. Additionally, paired box 6 (PAX6) was predicted as a putative target of miR‑874 using bioinformatics analysis. Further experiments demonstrated that PAX6 may be the direct target gene of miR‑874 in PDAC. PAX6 knockdown exhibited similar inhibitory effects to miR‑874 overexpression in PDAC cells. In addition, restored PAX6 expression may reverse the suppressive roles of miR‑874 overexpression in PDAC cells. The results demonstrated that miR‑874 may serve tumor suppressive roles in PDAC by directly targeting PAX6. Therefore, miR‑874 may exhibit potential applications for treatment of patients with PDAC.

Integrated Genomic and Immunophenotypic Classification of Pancreatic Cancer Reveals Three Distinct Subtypes with Prognostic/Predictive Significance

Purpose: Current clinical classification of pancreatic ductal adenocarcinoma (PDAC) is unable to predict prognosis or response to chemo- or immunotherapy and does not take into account the host reaction to PDAC cells. Our aim is to classify PDAC according to host- and tumor-related factors into clinically/biologically relevant subtypes by integrating molecular and microenvironmental findings.Experimental Design: A well-characterized PDAC cohort (n = 110) underwent next-generation sequencing with a hot spot cancer panel while next-generation tissue microarrays were immunostained for CD3, CD4, CD8, CD20, PD-L1, p63, hyaluronan-mediated motility receptor (RHAMM), and DNA mismatch repair proteins. Previous data on FOXP3 were integrated. Immune cell counts and protein expression were correlated with tumor-derived driver mutations, clinicopathologic features (TNM 8th edition, 2017), survival, and epithelial-mesenchymal transition (EMT)-like tumor budding.Results: Three PDAC subtypes were identified: the "immune escape" (54%), poor in T and B cells and enriched in FOXP3⁺ regulatory T cells (Treg), with high-grade budding, frequent CDKN2A, SMAD4, and PIK3CA mutations, and poor outcome; the "immune rich" (35%), rich in T and B cells and poorer in FOXP3⁺ Tregs, with infrequent budding, lower CDKN2A and PIK3CA mutation rate, and better outcome and a subpopulation with tertiary lymphoid tissue (TLT), mutations in DNA damage response genes (STK11 and ATM), and the best outcome; and the "immune exhausted" (11%), with immunogenic microenvironment and two subpopulations-one with PD-L1 expression and a high PIK3CA mutation rate and a microsatellite-unstable subpopulation with a high prevalence of JAK3 mutations. The combination of low budding, low stromal FOXP3 counts, presence of TLTs, and absence of CDKN2A mutations confers significant survival advantage in patients with PDAC.Conclusions: Immune host responses correlate with tumor characteristics, leading to morphologically recognizable PDAC subtypes with prognostic/predictive significance. Clin Cancer Res; 24(18); 4444-54. ©2018 AACRSee related commentary by Khalil and O'Reilly, p. 4355.

Five key lncRNAs considered as prognostic targets for predicting pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis, and the 5‐year survival rate was only 7.7%. To improve prognosis, a screening biomarker for early diagnosis of pancreatic cancer is in urgent need. Long non‐coding RNA (lncRNA) expression profiles as potential cancer prognostic biomarkers play critical roles in development of tumorigenesis and metastasis of cancer. However, lncRNA signatures in predicting the survival of a patient with PDAC remain unknown. In the current study, we try to identify potential lncRNA biomarkers and their prognostic values in PDAC. LncRNAs expression profiles and corresponding clinical information for 182 cases with PDAC were acquired from The Cancer Genome Atlas (TCGA). A total of 14 470 lncRNA were identified in the cohort, and 175 PDAC patients had clinical variables. We obtained 108 differential expressed lncRNA via R packages. Univariate and multivariate Cox proportional hazards regression, lasso regression was performed to screen the potential prognostic lncRNA. Five lncRNAs have been recognized to significantly correlate with OS. We established a linear prognostic model of five lncRNA (C9orf139, MIR600HG, RP5‐965G21.4, RP11‐436K8.1, and CTC‐327F10.4) and divided patients into high‐ and low‐risk group according to the prognostic index. The five lncRNAs played independent prognostic biomarkers of OS of PDAC patients and the AUC of the ROC curve for the five lncRNAs signatures prediction 5‐year survival was 0.742. In addition, targeted genes of MIR600HG, C9orf139, and CTC‐327F10.4 were explored and functional enrichment was also conducted. These results suggested that this five‐lncRNAs signature could act as potential prognostic biomarkers in the prediction of PDAC patient's survival.