Intratumoral delivery of shRNA targeting cyclin D1 attenuates pancreatic cancer growth

KRAS Promotes GLI2-Dependent Transcription during Pancreatic Carcinogenesis

Aberrant activation of GLI transcription factors has been implicated in the pathogenesis of different tumor types including pancreatic ductal adenocarcinoma. However, the mechanistic link with established drivers of this disease remains in part elusive. In this study, using a new genetically engineered mouse model overexpressing constitutively active mouse form of GLI2 and a combination of genome-wide assays, we provide evidence of a novel mechanism underlying the interplay between KRAS, a major driver of pancreatic ductal adenocarcinoma development, and GLI2 to control oncogenic gene expression. These mice, also expressing KrasG12D, show significantly reduced median survival rate and accelerated tumorigenesis compared with the KrasG12D only expressing mice. Analysis of the mechanism using RNA sequencing demonstrate higher levels of GLI2 targets, particularly tumor growth-promoting genes, including Ccnd1, N-Myc, and Bcl2, in KrasG12D mutant cells. Furthermore, chromatin immunoprecipitation sequencing studies showed that in these cells KrasG12D increases the levels of trimethylation of lysine 4 of the histone 3 (H3K4me3) at the promoter of GLI2 targets without affecting significantly the levels of other major active chromatin marks. Importantly, Gli2 knockdown reduces H3K4me3 enrichment and gene expression induced by mutant Kras. In summary, we demonstrate that Gli2 plays a significant role in pancreatic carcinogenesis by acting as a downstream effector of KrasG12D to control gene expression.

A Pancreatic Collision Tumor Comprising Mantle Cell Lymphoma and Adenocarcinoma: A Case Report and Literature Review

A collision tumor is a rare clinical condition where two different tumors occur synchronically within a lesion. Pancreatic collision tumors with mantle cell lymphoma (MCL) are extremely rare and have only been reported in one case to date. We herein report an elderly patient with MCL and adenocarcinoma of the pancreas with Ann Arbor stage IV and Union for International Cancer Control stage IIB, respectively. The patient received palliative therapy and died 23 months after the diagnosis. Further research and case studies are required to investigate whether or not MCL-derived cyclin D1 overexpression affects the occurrence/growth of adenocarcinomas.

Aloe emodin suppresses EGF‑induced neoplastic cell transformation by inhibiting the ERK/MSK1 and AKT/GSK3β signaling pathways

Natural compounds which can block cell transformation due to potential for chemoprevention have received increased attention. The present study aimed to investigate whether aloe emodin, which is present in aloe latex or the roots of the Rheum palmatum L. are able to block epidermal growth factor (EGF)‑ and tissue plasminogen activator‑induced JB6 C141 cell transformation. The aloe emodin treatment was applied to the JB6 C141 cell neoplastic model. The toxicity of aloe emodin was determined. The present study detected the expression level of AKT serine/threonine kinase 1 (AKT), lysine‑tRNA ligase MSK1 (MSK1) and cyclin D1 using western blotting. The cell proliferation and cell cycle distribution were also monitored. And when 95‑maximal effective dose ranged between 1 and 15 µM, the cell death was evident. Aloe emodin‑treated cells had an impaired anchorage‑independent growth capability, leading to a dose‑dependent reduction of colony formation. Western blotting revealed that aloe emodin had a significant effect on phosphorylation of pyruvate dehydrogenase kinase 1 and glycogen synthase kinase 3β (GSK3β) and AKT was inhibited. The present study determined that the proliferation of JB6 C141 cells was reduced in a dose‑dependent manner and the effect may be associated with its inhibition of the G1/S cell cycle transition. Cyclin D1 transcriptional activity was reduced to 25%, 24 h following aloe emodin treatment. The protein expression of cyclin D1 was inhibited. The findings of the present study indicated that aloe emodin may be able to suppress neoplastic cell transformation by inhibiting the extracellular‑signal regulated kinase/MSK1 and AKT/GSK3β signaling pathways. It may be a potential natural compound for chemoprevention.

Clinical significance and prospective molecular mechanism of MALAT1 in pancreatic cancer exploration: a comprehensive study based on the GeneChip, GEO, Oncomine, and TCGA databases

Purpose

Long noncoding RNAs (lncRNAs) are known to function as regulators in the development and occurrence of various tumors. MALAT1 is a highly conserved lncRNA and has vital functions in diverse tumors, including pancreatic cancer (PC). However, the underlying molecular regulatory mechanism involved in the occurrence and development of PC remains largely unknown. Thus, it is important to explore MALAT1 in PC and elucidate its function, which might offer a new perspective for clinical diagnosis and therapy.

Methods

First, we used the Gene Expression Omnibus, Oncomine, and The Cancer Genome Atlas databases to determine the clinical diagnostic and prognostic values of MALAT1. We next used our own GeneChip and The Cancer Genome Atlas database to collect the possible target genes of MALAT1 and further utilized a bioinformatics analysis to explore the underlying significant pathways that might be crucial in PC. Finally, we identified several key target genes of MALAT1 and hope to offer references for future research.

Results

We found that the expression of MALAT1 was significantly elevated in patients with PC. A receiver operating characteristics curve analysis showed a moderate diagnostic value (area under the curve =0.75, sensitivity =0.66, specificity =0.72). A total of 224 important overlapping genes were collected, and six hub genes (CCND1, MAPK8, VEGFA, FOS, CDH1, and HSP90AA1) were identified, of which CCND1, MAPK8, and VEGFA, are important genes in PC. Several pathways, including the mTOR signaling pathway, pathways in cancer, and the MAPK signaling pathway, were suggested to be the vital MALAT1 pathways in PC.

Conclusion

MALAT1 is suggested to be a promising diagnostic biomarker in PC. Six hub genes (CCND1, MAPK8, VEGFA, FOS, CDH1, and HSP90AA1), and specifically CCND1, MAPK8, and VEGFA, might be key MALAT1 target genes in PC. Due to their possible clinical significance in PC, several pathways, such as the mTOR signaling pathway, pathways in cancer, and the MAPK signaling pathway, are worthy of further study.

Breast Cancer Stem Cell Therapeutics, Multiple Strategies Versus Using Engineered Mesenchymal Stem Cells With Notch Inhibitory Properties: Possibilities and Perspectives

Relapse cases of cancers are more vigorous and difficult to control due to the preponderance of cancer stem cells (CSCs). Such CSCs that had been otherwise dormant during the first incidence of cancer gradually appear as radiochemoresistant cancer cells. Hence, cancer therapeutics aimed at CSCs would be an effective strategy for mitigating the cancers during relapse. Alternatively, CSC therapy can also be proposed as an adjuvant therapy, along-with the conventional therapies. As regenerative stem cells (RSCs) are known for their trophic effects, anti-tumorogenicity, and better migration toward an injury site, this review aims to address the use of adult stem cells such as dental pulp derived; cord blood derived pure populations of regenerative stem cells for targeting CSCs. Indeed, pro-tumorogenicity of RSCs is of concern and hence has also been dealt with in relation to breast CSC therapeutics. Furthermore, as notch signaling pathways are upregulated in breast cancers, and anti-notch antibody based and sh-RNA based therapies are already in the market, this review focuses the possibilities of engineering RSCs to express notch inhibitory proteins for breast CSC therapeutics. Also, we have drawn a comparison among various possibilities of breast CSC therapeutics, about, notch1 inhibition. J. Cell. Biochem. 119: 141-149, 2018. © 2017 Wiley Periodicals, Inc.

BCL9L expression in pancreatic neoplasia with a focus on SPN: a possible explanation for the enigma of the benign neoplasia

BACKGROUND

Solid pseudopapillary neoplasms of the pancreas (SPN) are rare tumors affecting mainly women. They show an activating mutation in CTNNB1, the gene for β-catenin, and consequently an overactivation of the Wnt/β-catenin pathway. This signaling pathway is implied in the pathogenesis of various aggressive tumors, including pancreatic adenocarcinomas (PDAC). Despite this, SPN are characterized by an unusually benign clinical course. Attempts to explain this lack of malignancy have led to the discovery of an aberrant expression of the transcription factor FLI1 in SPN.

METHODS

In 42 primary pancreatic tumors the RNA-expression of the FLI1 targets DKK1, INPP5D, IGFBP3 and additionally two members of the Wnt/β-catenin pathway, namely BCL9 and BCL9L, was investigated using quantitative real time PCR. Expression of these genes was evaluated in SPN (n = 18), PDAC (n = 12) and the less aggressive intraductal papillary mucinous neoplasm IPMN (n = 12) and compared to normal pancreatic tissue. Potential differences between the tumor entities were evaluated using students t-test.

RESULTS

The results demonstrated a differential RNA-expression of BCL9L with a lack of expression in SPN (p < 0.001), RNA levels similar to normal tissue in IPMN and increased expression in PDAC (p < 0.04). Further, overexpression of the cyclin D1 inhibitor INPP5D in IPMN (p < 0.0001) was found. PDAC, on the other hand, showed the highest expression of IGFBP3 (p < 0.00001) with the gene still being significantly overexpressed in IPMN (p < 0.001). Nevertheless the difference in expression was significant between PDAC and IPMN (p < 0.05) and IGFBP3 RNA levels were significantly higher in PDAC and IPMN than in SPN (p < 0.0001 and p < 0.02, resp.).

CONCLUSIONS

This study demonstrates a significantly decreased expression of the β-catenin stabilizing gene BCL9L in SPN as a first clue to the possible reasons for the astonishingly benign behavior of this entity. In contrast, high expression of the gene was detected in PDAC supporting the connection between BCL9L expression and tumor malignancy in pancreas neoplasias. IPMN, accordingly, showed intermediate expression of BCL9L, but instead demonstrated a high expression of the cyclin D1 inhibitor INPP5D, possibly contributing to the better prognosis of this neoplasia compared to PDAC.

Cyclin D1, p16(INK) (4A) and p27(Kip1) in pancreatic adenocarcinoma: assessing prognostic implications through quantitative image analysis

The prognostic significance of cyclin D1, p16(INK) (4A) and p27(Kip1) expression has been documented in several human malignancies; however, their prognostic potential in pancreatic adenocarcinoma is still unclear. This study aimed to assess the correlation of the aforementioned molecules with clinicopathological parameters and prognosis. Sixty patients with pancreatic ductal adenocarcinoma underwent surgical resection at a single institution; immunohistochemical staining of the studied markers was quantified by Ιmage analysis system. Cyclin D1 overexpression was positively associated with grade, neural infiltration and vascular invasion, whereas p27 positively correlated with age. Higher cyclin D1 expression indicated poorer survival (adjusted HR = 9.75, 95%CI: 1.48-64.31, p = 0.018, increment: one unit in H-score), whereas a marginal trend toward an association between p16 positivity and improved survival was observed (adjusted HR = 0.58, 95%CI: 0.32-1.05, p = 0.072 regarding positive vs negative cases). No significant association with overall survival was noted regarding p27. In conclusion, cyclin D1 overexpression and possibly p16 loss of expression in pancreatic adenocarcinoma seem to be adverse prognostic factors, whereas p27 expression did not seem to possess such prognostic properties. Further validation of the present findings in studies encompassing larger samples seems to be needed.

Intratumoral injection of PKR shRNA expressing plasmid inhibits B16-F10 melanoma growth

The RNA-dependent protein kinase (PKR) is a serine/threonine kinase that is involved in the regulation of important cell processes such as apoptosis, signal transduction, cell proliferation and differentiation. However, the role played by PKR in cancer remains controversial. RNA interference (RNAi) has currently become an important technique in understanding gene function. Previously, we showed that PKR shRNA downregulates PKR expression in B16-F10 melanoma cells and reduces the metastatic potential of these tumor cells. In the present study, we examined the effect of the intratumoral injection of PKR shRNA‑expressing plasmid on the growth of B16-F10 melanoma in mice. The results showed that this treatment significantly reduced tumor growth. Thus, these findings suggested that PKR acts as a tumor suppressor, a finding that is consistent with our previous study on the experimental model of metastasis. Moreover, the results suggested that this effect may be mediated by the transcription factor NF-κB. The present study confirmed the hypothesis that the direct administration of RNAi-based therapeutics in the target tumor is a promising approach for overcoming the obstacles of systemic delivery. The results also suggested that the intratumoral injection of PKR shRNA‑expressing vector is a novel therapeutic approach for human solid tumors such as cutaneous melanoma and breast cancer, since PKR is overexpressed in these tumors.

Therapeutic effects of lentivirus-mediated shRNA targeting of cyclin D1 in human gastric cancer

Background

Gastric cancer is the second most common cause of cancer-related death in males and the fourth in females. Traditional treatment has poor prognosis because of recurrence and systemic side effects. Therefore, the development of new therapeutic strategies is an important issue. Lentivirus-mediated shRNA stably inhibits target genes and can efficiently transduce most cells. Since overexpressed cyclin D1 is closely related to human gastric cancer progression, inhibition of cyclin D1 using specific targeting could be an effective treatment method of human gastric cancer.

Methods

The therapeutic effect of lentivirus-mediated shRNA targeting of cyclin D1 (ShCCND1) was analyzed both in vitro and in vivo experiments.

Results

In vitro, NCI-N87 cells with downregulation of cyclin D1 by ShCCND1 showed significant inhibition of cell proliferation, cell motility, and clonogenicity. Downregulation of cyclin D1 in NCI-N87 cells also resulted in significantly increased G1 arrest and apoptosis. In vivo, stable NCI-N87 cells expressing ShCCND1 were engrafted into nude mice. Then, the cancer-growth inhibition effect of lentivirus was confirmed. To assess lentivirus including ShCCND1 as a therapeutic agent, intratumoral injection was conducted. Tumor growth of the lentivirus-treated group was significantly inhibited compared to growth of the control group. These results are in accordance with the in vitro data and lend support to the mitotic figure count and apoptosis analysis of the tumor mass.

Conclusion

The lentivirus-mediated ShCCND1 was constructed, which effectively inhibited growth of NCI-N87-derived cancer both in vitro and in vivo. The efficiency of shRNA knockdown and variation in the degree of inhibition is mediated by different shRNA sequences and cancer cell lines. These experimental results suggest the possibility of developing new gastric cancer therapies using lentivirus-mediated shRNA.

PV1 down-regulation via shRNA inhibits the growth of pancreatic adenocarcinoma xenografts

PV1 is an endothelial-specific protein with structural roles in the formation of diaphragms in endothelial cells of normal vessels. PV1 is also highly expressed on endothelial cells of many solid tumours. On the basis of in vitro data, PV1 is thought to actively participate in angiogenesis. To test whether or not PV1 has a function in tumour angiogenesis and in tumour growth in vivo, we have treated pancreatic tumour-bearing mice by single-dose intratumoural delivery of lentiviruses encoding for two different shRNAs targeting murine PV1. We find that PV1 down-regulation by shRNAs inhibits the growth of established tumours derived from two different human pancreatic adenocarcinoma cell lines (AsPC-1 and BxPC-3). The effect observed is because of down-regulation of PV1 in the tumour endothelial cells of host origin, PV1 being specifically expressed in tumour vascular endothelial cells and not in cancer or other stromal cells. There are no differences in vascular density of tumours treated or not with PV1 shRNA, and gain and loss of function of PV1 in endothelial cells does not modify either their proliferation or migration, suggesting that tumour angiogenesis is not impaired. Together, our data argue that down-regulation of PV1 in tumour endothelial cells results in the inhibition of tumour growth via a mechanism different from inhibiting angiogenesis.

Identification of novel predictive markers for the prognosis of pancreatic ductal adenocarcinoma

Pancreatic cancer is a disease with poor prognosis and high mortality. To identify novel molecular markers that could predict the prognosis of pancreatic ductal adenocarcinoma, a total of 114 pancreatic ductal adenocarcinomas and 99 peritumoral tissues were collected. Protein levels of cleaved caspase-3, cyclin D1, epidermal growth factor receptor and Her-2 (human epidermal growth factor receptor 2) were measured by immunohistochemistry. Molecular abnormalities of cyclin D1/q11, Her-2/q17, and epidermal growth factor receptor/p7 were detected using fluorescence in situ hybridization. Results demonstrated that the protein levels of cleaved caspase-3, epidermal growth factor receptor, Her-2, and cyclin D1 were significantly higher in pancreatic ductal adenocarcinoma than that in peritumoral tissues (P = .000). Significantly more amplifications of epidermal growth factor receptor, Her-2, and cyclin D1 were observed in pancreatic ductal adenocarcinoma patients than in peritumoral tissues. In addition, 51.8% of pancreatic ductal adenocarcinoma tumors showed polysomy 7, 50% showed polysomy 11, and 40.4% showed polysomy 17. However, no polysomy was observed in peritumoral tissues. Her-2 amplification and polysomy 17 significantly correlated with poor prognosis of pancreatic ductal adenocarcinoma (P = .008 and P = .005, respectively). Interestingly, only cleaved caspase-3 protein level significantly correlated with poor survival in pancreatic ductal adenocarcinoma patients (P = .000). We also observed significant correlations of cleaved caspase-3 level with epidermal growth factor receptor, Her-2, and cyclin D1 protein levels and the molecular abnormalities of Her-2 and cyclin D1. Conclusively, cleaved caspase-3 level is an ideal biomarker to predict prognosis in pancreatic ductal adenocarcinoma patients and might be a better target for pancreatic ductal adenocarcinoma treatment than epidermal growth factor receptor/Her-2 and cyclin D1.

Identification of NME5 as a contributor to innate resistance to gemcitabine in pancreatic cancer cells

The limited therapeutic effect of gemcitabine on pancreatic cancer is largely attributed to pre-existing or acquired resistance of the tumor cells. This study was aimed at screening for candidate resistance-related gene(s) and elucidating the underlying mechanisms. NME5 was found to be highly expressed in an innate gemcitabine-resistant human pancreatic cancer sample and the cell line PAXC002 derived from the sample. Downregulation of NME5 significantly reversed gemcitabine resistance in PAXC002 cells, whereas NME5 overexpression induced gemcitabine resistance in the pancreatic cancer cell line BxPC-3. NME5 attenuated the induction of apoptosis and cell cycle arrest induced by gemcitabine, probably accounting for the blunted sensitivity to gemcitabine. Furthermore, NME5 was demonstrated to play its role in a nuclear factor kappaB (NF-κB)-dependent manner. NME5 was capable of directly binding NF-κB, and possibly regulated its expression level in PAXC002 cells. Our results also suggest that NF-κB is a key executor of NME5 in regulating apoptosis and cell cycle. All of these data suggest that NME5 is a promising target for relieving innate gemcitabine resistance in pancreatic cancer cells.

Pancreatic cancer gene therapy: from molecular targets to delivery systems

The continuous identification of molecular changes deregulating critical pathways in pancreatic tumor cells provides us with a large number of novel candidates to engineer gene-targeted approaches for pancreatic cancer treatment. Targets—both protein coding and non-coding—are being exploited in gene therapy to influence the deregulated pathways to facilitate cytotoxicity, enhance the immune response or sensitize to current treatments. Delivery vehicles based on viral or non-viral systems as well as cellular vectors with tumor homing characteristics are a critical part of the design of gene therapy strategies. The different behavior of tumoral versus non-tumoral cells inspires vector engineering with the generation of tumor selective products that can prevent potential toxic-associated effects. In the current review, a detailed analysis of the different targets, the delivery vectors, the preclinical approaches and a descriptive update on the conducted clinical trials are presented. Moreover, future possibilities in pancreatic cancer treatment by gene therapy strategies are discussed.

Differential roles of cyclin D1 and D3 in pancreatic ductal adenocarcinoma

Background

The cyclin D1 (CCND1) and cyclin D3 (CCND3) are frequently co-overexpressed in pancreatic ductal adenocarcinoma (PDAC). Here we examine their differential roles in PDAC.

Results

CCND1 and CCND3 expression were selectively suppressed by shRNA in PDAC cell lines with expression levels of equal CCND1 and CCND3 (BxPC3), enhanced CCND1 (HPAC) or enhanced CCND3 (PANC1). Suppression of cell proliferation was greater with CCND3 than CCND1 downregulation. CCND3 suppression led to a reduced level of phosphorylated retinoblastoma protein (^Ser795p-Rb/p110) and resulted in decreased levels of cyclin A mRNA and protein. A global gene expression analysis identified deregulated genes in D1- or D3-cyclin siRNA-treated PANC1 cells. The downregulated gene targets in CCND3 suppressed cells were significantly enriched in cell cycle associated processes (p < 0.005). In contrast, focal adhesion/actin cytoskeleton, MAPK and NF B signaling appeared to characterize the target genes and their interacting proteins in CCND1 suppressed PANC1 cells.

Conclusions

Our results suggest that CCND3 is the primary driver of the cell cycle, in cooperation with CCND1 that integrates extracellular mitogenic signaling. We also present evidence that CCND1 plays a role in tumor cell migration. The results provide novel insights for common and differential targets of CCND1 and CCND3 overexpression during pancreatic duct cell carcinogenesis.