Activation of WNT/β-Catenin Signaling Enhances Pancreatic Cancer Development and the Malignant Potential Via Up-regulation of Cyr61

Role of Wnt/β-catenin pathway in cancer drug resistance: Insights into molecular aspects of major solid tumors

Adaptive resistance to conventional and targeted therapies remains one of the major obstacles in the effective management of cancer. Aberrant activation of key signaling mechanisms plays a pivotal role in modulating resistance to drugs. An evolutionarily conserved Wnt/β-catenin pathway is one of the signaling cascades which regulate resistance to drugs. Elevated Wnt signaling confers resistance to anticancer therapies, either through direct activation of its target genes or via indirect mechanisms and crosstalk over other signaling pathways. Involvement of the Wnt/β-catenin pathway in cancer hallmarks like inhibition of apoptosis, promotion of invasion and metastasis and cancer stem cell maintenance makes this pathway a potential target to exploit for addressing drug resistance. Accumulating evidences suggest a critical role of Wnt/β-catenin pathway in imparting resistance across multiple cancers including PDAC, NSCLC, TNBC, etc. Here we present a comprehensive assessment of how Wnt/β-catenin pathway mediates cancer drug resistance in majority of the solid tumors. We take a deep dive into the Wnt/β-catenin signaling-mediated modulation of cellular and downstream molecular mechanisms and their impact on cancer resistance.

Investigating underlying molecular mechanisms, signaling pathways, emerging therapeutic approaches in pancreatic cancer

Pancreatic adenocarcinoma, a clinically challenging malignancy constitutes a significant contributor to cancer-related mortality, characterized by an inherently poor prognosis. This review aims to provide a comprehensive understanding of pancreatic adenocarcinoma by examining its multifaceted etiologies, including genetic mutations and environmental factors. The review explains the complex molecular mechanisms underlying its pathogenesis and summarizes current therapeutic strategies, including surgery, chemotherapy, and emerging modalities such as immunotherapy. Critical molecular pathways driving pancreatic cancer development, including KRAS, Notch, and Hedgehog, are discussed. Current therapeutic strategies, including surgery, chemotherapy, and radiation, are discussed, with an emphasis on their limitations, particularly in terms of postoperative relapse. Promising research areas, including liquid biopsies, personalized medicine, and gene editing, are explored, demonstrating the significant potential for enhancing diagnosis and treatment. While immunotherapy presents promising prospects, it faces challenges related to immune evasion mechanisms. Emerging research directions, encompassing liquid biopsies, personalized medicine, CRISPR/Cas9 genome editing, and computational intelligence applications, hold promise for refining diagnostic approaches and therapeutic interventions. By integrating insights from genetic, molecular, and clinical research, innovative strategies that improve patient outcomes can be developed. Ongoing research in these emerging fields holds significant promise for advancing the diagnosis and treatment of this formidable malignancy.

Advances in Making Cancer Mouse Models More Accessible and Informative through Non-Germline Genetic Engineering

Genetically engineered mouse models (GEMMs) allow for modeling of spontaneous tumorigenesis within its native microenvironment in mice and have provided invaluable insights into mechanisms of tumorigenesis and therapeutic strategies to treat human disease. However, as their generation requires germline manipulation and extensive animal breeding that is time-, labor-, and cost-intensive, traditional GEMMs are not accessible to most researchers, and fail to model the full breadth of cancer-associated genetic alterations and therapeutic targets. Recent advances in genome-editing technologies and their implementation in somatic tissues of mice have ushered in a new class of mouse models: non-germline GEMMs (nGEMMs). nGEMM approaches can be leveraged to generate somatic tumors de novo harboring virtually any individual or group of genetic alterations found in human cancer in a mouse through simple procedures that do not require breeding, greatly increasing the accessibility and speed and scale on which GEMMs can be produced. Here we describe the technologies and delivery systems used to create nGEMMs and highlight new biological insights derived from these models that have rapidly informed functional cancer genomics, precision medicine, and immune oncology.

METTL3 regulates FAM83D m6A modification to accelerate tumorigenesis of triple-negative breast cancer via the Wnt/β-catenin pathway

N6-methyladenosine (m6A) modification, the most abundant methylation modification on eukaryotic mRNAs, was implicated in the tumourigenesis. This study aimed to explore the role of methyltransferase like 3 (METTL3) in triple-negative breast cancer progression and its underlying mechanisms. FAM83D was markedly elevated in triple-negative breast cancer tissues and cells, and high expression of FAM83D was related to the poor prognosis of triple-negative breast cancer patients. FAM83D knockdown significantly retarded cell proliferation, invasion, stemness, and accelerated cell apoptosis in triple-negative breast cancer cells. On the contrary, overexpression of FAM83D promoted the malignant behaviors. METTL3 could interact with FAM83D and mediate m6A modification of FAM838D. Moreover, METTL3 positively regulated FAM83D expression, and FAM83D overexpression could block the inhibition effects of MRTTL3 knockdown on the malignant behaviors. METTL3 knockdown decreased FAM83D expression to inhibit the Wnt/β-catenin pathway. In addition, knockdown of FAM83D also showed the repressive effects on tumor growth in triple-negative breast cancer in vivo. These findings suggested that METTL3 could modulate FAM83D protein expression through m6A modification to aggravate triple-negative breast cancer progression via the Wnt/β-catenin pathway.

Top advances of the year: Pancreatic cancer

This commentary highlights the key recent advances made in the field of pancreatic cancer. Although there has yet to be a major breakthrough in clinical care for the majority of patients, significant strides have been made in understanding the complex biology of this malignancy and identifying new therapeutic targets.

Similarity of oncogenic protein expression in KRASG12D gene delivery-based rat pancreatic cancer model to that of human pancreatic cancer

BACKGROUND

The development of effective therapies and biomarkers for pancreatic cancer is an unmet clinical need. To address this, we have developed an easy-to-use pancreatic cancer rat animal model via pancreas-targeted hydrodynamic gene delivery of human pancreatic cancer-related genes. Our study aimed to determine the molecular similarity between the pancreatic tumor in the rat model and human pancreatic cancer.

METHODS

KRASG12D gene-expressing plasmid was delivered to the pancreas of wild type rats via pancreas-targeted hydrodynamic gene delivery as previously reported. Tissue samples were collected at 5 weeks after the first gene delivery. The tumors developed in the rats were assessed for the expression of oncogenic proteins that are involved in human pancreatic cancer development.

RESULTS

The development of a tumor mimicking pancreatic ductal adenocarcinoma was confirmed. The expression levels of Cyclin D1, c-Jun, IL-33, and Zip4 proteins in the tumor were immunohistochemically assessed and the correlation of the proteins was confirmed. The expression pattern showed similarity to that of surgically resected human pancreatic cancer tissues.

CONCLUSIONS

Our study findings showing a similar pattern of oncogenic protein expression in novel KRASG12D gene-induced rat pancreatic cancer model and human pancreatic cancer will be useful for establishing novel tumor markers and therapeutic options for pancreatic cancer.

Targeted therapy for pancreatic ductal adenocarcinoma: Mechanisms and clinical study

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and lethal malignancy with a high rate of recurrence and a dismal 5-year survival rate. Contributing to the poor prognosis of PDAC is the lack of early detection, a complex network of signaling pathways and molecular mechanisms, a dense and desmoplastic stroma, and an immunosuppressive tumor microenvironment. A recent shift toward a neoadjuvant approach to treating PDAC has been sparked by the numerous benefits neoadjuvant therapy (NAT) has to offer compared with upfront surgery. However, certain aspects of NAT against PDAC, including the optimal regimen, the use of radiotherapy, and the selection of patients that would benefit from NAT, have yet to be fully elucidated. This review describes the major signaling pathways and molecular mechanisms involved in PDAC initiation and progression in addition to the immunosuppressive tumor microenvironment of PDAC. We then review current guidelines, ongoing research, and future research directions on the use of NAT based on randomized clinical trials and other studies. Finally, the current use of and research regarding targeted therapy for PDAC are examined. This review bridges the molecular understanding of PDAC with its clinical significance, development of novel therapies, and shifting directions in treatment paradigm.

TGF-β2 antisense oligonucleotide enhances T-cell mediated anti-tumor activities by IL-2 via attenuation of fibrotic reaction in a humanized mouse model of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, with high mortality and recurrence rate. In this study, we generated a human immune system mouse model by transplanting human peripheral blood mononuclear cells into NSG-B2m mice followed by xenografting AsPC-1 cells, after which we assessed the role of transforming growth factor-β2 (TGF-β2) in T-cell-mediated anti-tumor immunity. We observed that inhibiting the TGF-β2 production by TGF-β2 antisense oligonucleotide (TASO) combined with IL-2 delays pancreatic cancer growth. Co-treatment of TASO and IL-2 had little effect on the SMAD-dependent pathway, but significantly inhibited the Akt phosphorylation and sequentially activated GSK-3β. Activation of GSK-3β by TASO subsequently suppressed β-catenin and α-SMA expression and resulted in attenuated fibrotic reactions, facilitating the infiltration of CD8 + cytotoxic T lymphocytes (CTLs) into the tumor. TGF-β2 inhibition suppressed the Foxp3 + regulatory T-cells in peripheral blood and tumors, thereby enhancing the tumoricidal effects of CTLs associated with increased granzyme B and cleaved caspase-3. Moreover, changes in the T-cell composition in peripheral blood and at the tumor site by TASO and IL-2 induced the increase of pro-inflammatory cytokines such as IFN-γ and TNF-α and the decrease of anti-inflammatory cytokines such as TGF-βs. These results indicate that the TGF-β2 inhibition by TASO combined with IL-2 enhances the T-cell mediated anti-tumor immunity against SMAD4-mutated PDAC by modulating the tumor-associated fibrosis, suggesting that TASO in combination with IL-2 may be a promising immunotherapeutic intervention for PDAC.

WNT signaling in the tumor microenvironment promotes immunosuppression in murine pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is associated with activation of WNT signaling. Whether this signaling pathway regulates the tumor microenvironment has remained unexplored. Through single-cell RNA sequencing of human pancreatic cancer, we discovered that tumor-infiltrating CD4+ T cells express TCF7, encoding for the transcription factor TCF1. We conditionally inactivated Tcf7 in CD4 expressing T cells in a mouse model of pancreatic cancer and observed changes in the tumor immune microenvironment, including more CD8+ T cells and fewer regulatory T cells, but also compensatory upregulation of PD-L1. We then used a clinically available inhibitor of Porcupine, a key component of WNT signaling, and observed similar reprogramming of the immune response. WNT signaling inhibition has limited therapeutic window due to toxicity, and PD-L1 blockade has been ineffective in PDA. Here, we show that combination targeting reduces pancreatic cancer growth in an experimental model and might benefit the treatment of pancreatic cancer.

Cysteine-rich 61(CYR61) alleviates cyclophosphamide-induced proliferation inhibition in ovarian granulosa cells via suppressing NLRP3/caspase1-mediated pyroptosis

BACKGROUND

We investigated the level of Cysteine-rich 61 (CYR61) in premature ovarian failure as well as its regulatory molecular mechanism in this study.

METHODS AND RESULTS

Cyclophosphamide (CTX) was used to induce OGCs (rat ovarian granulosa cells) and rats to establish in vivo and in vitro premature ovarian failure models. H&E staining was used to detect the pathological changes of ovarian histopathology. Si-NLRP3 (NOD-like receptor thermal protein domain associated protein 3, NLRP3) and si-CYR61 were transfected into OGCs using lipofectamine 3000. RT-qPCR and western blot were used to detect the expressions of CYR61 in ovarian tissue and OGCs. It showed that the expression of CYR61 was significantly down-regulated in premature ovarian failure model. Cell viability was detected using a Cell Counting Kit-8 (CCK-8) kit. TUNEL (Terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling) staining was used to detect the apoptosis. 5-Ethynyl-2'-deoxyuridine (EdU) and SA-β-gal (senescence-associated β-galactosidase) staining were used to assess the proliferation and senescence. The expression of CYR61 in OGCs and ovarian tissues were detected by immunofluorescence and immunohistochemical staining. Overexpression of CYR61 significantly promoted OGCs proliferation and inhibited pyroptosis and apoptosis. Western blot was used to detect the protein expressions of p53 and p21 in OGCs. Flow cytometry was used to detect the pyroptosis. CYR61 overexpression inhibited the expression of NLRP3 and caspase-1 in CTX-induced OGCs according to western blot results. Moreover, we found that CYR61 overexpression down-regulated the protein expressions of p53 and p21 in CTX-induced OGCs.

CONCLUSION

CYR61 inhibited CTX-induced OGCs senescence, and the mechanism may be related to the regulation of caspase-1/NLRP3-induced pyroptosis.

Targeting ligand-dependent wnt pathway dysregulation in gastrointestinal cancers through porcupine inhibition

Gastrointestinal cancers are responsible for more cancer deaths than any other system of the body. This review summarises how Wnt pathway dysregulation contributes to the development of the most common gastrointestinal cancers, with a particular focus on the nature and frequency of upstream pathway aberrations. Tumors with upstream aberrations maintain a dependency on the presence of functional Wnt ligand, and are predicted to be tractable to inhibitors of Porcupine, an enzyme that plays a key role in Wnt secretion. We summarise available pre-clinical efficacy data from Porcupine inhibitors in vitro and in vivo, as well as potential toxicities and the data from early phase clinical trials. We appraise the rationale for biomarker-defined targeted approaches, as well as outlining future opportunities for combination with other therapeutics.

Regulation of CyR61 expression and release by 3-mercaptopyruvate sulfurtransferase in colon cancer cells

Cysteine-rich angiogenic inducer 61 (CYR61, also termed CCN family member 1 or CCN1), is a matricellular protein encoded by the CYR61 gene. This protein has been implicated in the regulation of various cancer-associated processes including tumor growth, angiogenesis, tumor cell adhesion, migration, and invasion as well as the regulation of anticancer drug resistance. Hydrogen sulfide (H₂S) is a gaseous endogenous biological mediator, involved in the regulation of cellular bioenergetics, angiogenesis, invasion, and chemotherapeutic resistance in several types of cancer. H₂S is produced by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST). The current studies were set up to investigate if CBS or 3-MST regulates CyR61 in colon cancer cells in the context of the regulation of proliferation, migration, and survival. The study mainly utilized HCT116 cells, in which two of the principal H₂S-producing enzymes, CBS and 3-MST, are highly expressed. The H₂S donor GYY4137 and the polysulfide donor Na₂S₃ activated the CyR61 promoter in a concentration-dependent fashion. Aminooxyacetic acid (AOAA), a pharmacological inhibitor of CBS as well as HMPSNE: 2-[(4-hydroxy-6- methylpyrimidin-2-yl)sulfanyl]-1-(naphthalen-1-yl)ethan-1-one, a pharmacological inhibitor of 3-MST inhibited CyR61 mRNA expression. This effect was more pronounced in response to HMPSNE than to AOAA and occurred through the modulation of S1PR via ATF1 and CREB. CyR61 was found to play an active, but relatively minor role in maintaining colon cell proliferation. HMPSNE markedly suppressed the secretion/release of CyR61 from the colon cancer cells. Moreover, HMPSNE promoted colon cancer cell apoptosis; endogenously produced CyR61 was found to counteract this effect, at least in part via RhoA activation. Taken together, we conclude that the upregulation of 3-MST in cancer cells exerts cytoprotective effects and confers the cancer cells a more aggressive phenotype - at least in part via the modulation of CyR61 expression and release.

CFTR and Gastrointestinal Cancers: An Update

Cystic Fibrosis (CF) is a disease caused by mutations in the CFTR gene that severely affects the lungs as well as extra-pulmonary tissues, including the gastrointestinal (GI) tract. CFTR dysfunction resulting from either mutations or the downregulation of its expression has been shown to promote carcinogenesis. An example is the enhanced risk for several types of cancer in patients with CF, especially cancers of the GI tract. CFTR also acts as a tumor suppressor in diverse sporadic epithelial cancers in many tissues, primarily due to the silencing of CFTR expression via multiple mechanisms, but especially due to epigenetic regulation. This review provides an update on the latest research linking CFTR-deficiency to GI cancers, in both CF patients and in sporadic GI cancers, with a particular focus on cancer of the intestinal tract. It will discuss changes in the tissue landscape linked to CFTR-deficiency that may promote cancer development such as breakdowns in physical barriers, microbial dysbiosis and inflammation. It will also discuss molecular pathways and mechanisms that act upstream to modulate CFTR expression, such as by epigenetic silencing, as well as molecular pathways that act downstream of CFTR-deficiency, such as the dysregulation of the Wnt/β-catenin and NF-κB signaling pathways. Finally, it will discuss the emerging CFTR modulator drugs that have shown promising results in improving CFTR function in CF patients. The potential impact of these modulator drugs on the treatment and prevention of GI cancers can provide a new example of personalized cancer medicine.

Implication of ERBB2 as a Predictive Tool for Survival in Patients with Pancreatic Cancer in Histological Studies

Pancreatic cancer will be positioned by the year 2030 as the second cause of oncological death after lung cancer. The pathophysiology of the most common variety, which involves the adenocarcinoma of the pancreas, represents one of the main challenges for current oncology to explain its tumorigenesis and create a targeted treatment. The tumor microenvironment, metastatic capacity, and lack of early diagnosis lead patients to present advanced stages at the time of diagnosis. Despite numerous efforts, little progress has been made in clinical outcomes and with respect to the improved survival of these patients. For this reason, in recent years, numerous diagnostic tests, treatments, and possible approaches in the fields of radiotherapy, chemotherapy, immunotherapy, and surgery have been developed to find a combination of methods that improves life expectancy in patients diagnosed with this disease. On the other hand, the scientific community has made numerous advances in the molecular bases of pancreatic cancer since several oncogenetic pathways have been described and the markers expressed by the tumor have proven to be useful in the prognosis of pancreatic adenocarcinoma. These molecular alterations allow the study of possible therapeutic targets that improve the prognosis of these patients, but even numerous tumor cell-individual interactions must be explained to understand the underlying pathophysiology causing the high mortality. Therefore, the purpose of our study is to examine the expression of markers such as EGFR, Cyclin D1, andCDK4 in order to find a relationship with the possible long-term prognostic factors of patients affected by pancreatic ductal adenocarcinoma. Our results show that there is a prognostic role for ErbB2, EGFR, beta catenin, cyclin D1, and CDK4. Of these, we highlight the clinical importance of ErbB2 in the survival rates of patients who overexpress this component.

Targeting Wnt/tenascin C-mediated cross talk between pancreatic cancer cells and stellate cells via activation of the metastasis suppressor NDRG1

A major barrier to successful pancreatic cancer (PC) treatment is the surrounding stroma, which secretes growth factors/cytokines that promote PC progression. Wnt and tenascin C (TnC) are key ligands secreted by stromal pancreatic stellate cells (PSCs) that then act on PC cells in a paracrine manner to activate the oncogenic β-catenin and YAP/TAZ signaling pathways. Therefore, therapies targeting oncogenic Wnt/TnC cross talk between PC cells and PSCs constitute a promising new therapeutic approach for PC treatment. The metastasis suppressor N-myc downstream-regulated gene-1 (NDRG1) inhibits tumor progression and metastasis in numerous cancers, including PC. We demonstrate herein that targeting NDRG1 using the clinically trialed anticancer agent di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) inhibited Wnt/TnC-mediated interactions between PC cells and the surrounding PSCs. Mechanistically, NDRG1 and DpC markedly inhibit secretion of Wnt3a and TnC by PSCs, while also attenuating Wnt/β-catenin and YAP/TAZ activation and downstream signaling in PC cells. This antioncogenic activity was mediated by direct inhibition of β-catenin and YAP/TAZ nuclear localization and by increasing the Wnt inhibitor, DKK1. Expression of NDRG1 also inhibited transforming growth factor (TGF)-β secretion by PC cells, a key mechanism by which PC cells activate PSCs. Using an in vivo orthotopic PC mouse model, we show DpC downregulated β-catenin, TnC, and YAP/TAZ, while potently increasing NDRG1 expression in PC tumors. We conclude that NDRG1 and DpC inhibit Wnt/TnC-mediated interactions between PC cells and PSCs. These results further illuminate the antioncogenic mechanism of NDRG1 and the potential of targeting this metastasis suppressor to overcome the oncogenic effects of the PC-PSC interaction.

MicroRNA‑190b expression predicts a good prognosis and attenuates the malignant progression of pancreatic cancer by targeting MEF2C and TCF4

MicroRNAs (miRNAs/miRs) are key components of regulatory networks in cancer. Although miR-190b is an important tumor-related miRNA, its role in pancreatic cancer has not been extensively investigated. The aim of the present study was to examine the expression of miR-190b in pancreatic cancer cell lines and tissues and evaluate its effects on cancer progression. Reverse transcription-quantitative PCR (RT-qPCR) analysis was used to measure miR-190b expression levels in human pancreatic cancer cell lines and tissues, and the association between miR-190b expression and clinicopathological characteristics was assessed. An in vitro Transwell invasion assay and an in vivo metastasis formation assay were performed using pancreatic cancer cells. The effect of miR-190b on pancreatic cancer cell proliferation was evaluated using a Cell Counting Kit-8 assay based on an in vivo xenograft mouse model. The direct targets of miR-190b were predicted using bioinformatics tools and were validated through western blotting and luciferase reporter assays. Pancreatic cancer cell lines and tissues were found to express lower levels of miR-190b compared with normal cells and adjacent non-tumor tissues. Furthermore, high expression of miR-190b was found to be positively correlated with low T, N and American Joint Committee on Cancer classifications, and predicted a good prognosis. miR-190b was shown to exert suppressive effects on cancer cell proliferation, invasion and metastasis. In addition, it was also found that miR-190b directly targeted myocyte enhancer factor 2C (MEF2C) and transcription factor 4 (TCF4) in pancreatic cancer, thus serving as a tumor suppressor and a predictor of good prognosis in pancreatic cancer. The immunohistochemistry and RT-qPCR results indicated that the MEF2C and TCF4 expression levels were negatively correlated with the miR-190b expression levels. The findings of the present study highlight the value of miR-190b as a novel target candidate for pancreatic cancer diagnosis and therapy.

Context Matters-Why We Need to Change From a One Size Fits all Approach to Made-to-Measure Therapies for Individual Patients With Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers and remains a major unsolved health problem. While pancreatic ductal adenocarcinoma (PDAC) is associated with driver mutations in only four major genes (KRAS, TP53, SMAD4, and CDKN2A), every tumor differs in its molecular landscape, histology, and prognosis. It is crucial to understand and consider these differences to be able to tailor treatment regimens specific to the vulnerabilities of the individual tumor to enhance patient outcome. This review focuses on the heterogeneity of pancreatic tumor cells and how in addition to genetic alterations, the subsequent dysregulation of multiple signaling cascades at various levels, epigenetic and metabolic factors contribute to the oncogenesis of PDAC and compensate for each other in driving cancer progression if one is tackled by a therapeutic approach. This implicates that besides the need for new combinatorial therapies for PDAC, a personalized approach for treating this highly complex cancer is required. A strategy that combines both a target-based and phenotypic approach to identify an effective treatment, like Reverse Clinical Engineering® using patient-derived organoids, is discussed as a promising way forward in the field of personalized medicine to tackle this deadly disease.

PDIA6 promotes pancreatic cancer progression and immune escape through CSN5-mediated deubiquitination of β-catenin and PD-L1

Protein Disulfide Isomerase Family A Member 6 (PDIA6) is an endoplasmic reticulum protein that is capable of catalyzing protein folding and disulfide bond formation. Abnormally elevated expression of PDIA6 has been reported to predict poor outcomes in various cancers. Herein, gain-of- and loss-of-function experiments were performed to investigate how PDIA6 participated in the carcinogenesis of pancreatic cancer (PC). By analyzing the protein expression of PDIA6 in 28 paired PC and para carcinoma specimens, we first found that PDIA6 expression was higher in PC samples. Both the overall survival and disease-free survival rates of PC patients with higher PDIA6 expression were poorer than those with lower PDIA6 (n = 178). Furthermore, knockdown of PDIA6 impaired the malignancies of PC cells - suppressed cell proliferation, invasion, migration, cisplatin resistance, and xenografted tumor growth. PDIA6-silenced PC cells were more sensitive to cytotoxic natural killer (NK) cells. Overexpression of PDIA6 had opposite effects on PC cells. Interestingly, COP9 signalosome subunit 5 (CSN5), a regulator of E3 ubiquitin ligases known to promote deubiquitination of its downstream targets, was demonstrated to interact with PDIA6, and its expression was increased in PC cells overexpressing PDIA6. Additionally, PDIA6 overexpression promoted deubiquitination of β-catenin and PD-L1 and subsequently upregulated their expression in PC cells. These alterations were partly reversed by CSN5 shRNA. Collectively, the above results demonstrate that PDIA6 contributes to PC progression, which may be associated with CSN5-regulated deubiquitination of β-catenin and PD-L1. Our findings suggest PDIA6 as a potential target for the treatment of PC.

Overcoming the Tumor Microenvironmental Barriers of Pancreatic Ductal Adenocarcinomas for Achieving Better Treatment Outcomes

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive disease with the lowest survival rate among all solid tumors. The lethality of PDAC arises from late detection and propensity of the tumor to metastasize and develop resistance against chemo and radiation therapy. A highly complex tumor microenvironment composed of dense stroma, immune cells, fibroblast, and disorganized blood vessels, is the main obstacle to current PDAC therapy. Despite the tremendous success of immune checkpoint inhibitors (ICIs) in cancers, PDAC remains one of the poorest responders of ICIs therapy. The immunologically "cold" phenotype of PDAC is attributed to the low mutational burden, high infiltration of myeloid-derived suppressor cells and T-regs, contributing to a significant immunotherapy resistance mechanism. Thus, the development of innovative strategies for turning immunologically "cold" tumor into "hot" ones is an unmet need to improve the outcome of PDAC ICIs therapies. Other smart strategies, such as nanomedicines, sonic Hedgehog inhibitor, or smoothened inhibitor, are discussed to enhance chemotherapeutic agents' efficiency by disrupting the PDAC stroma. This review highlights the current challenges and various preclinical and clinical strategies to overcome current PDAC therapy difficulties, thus significantly advancing PDAC research knowledge.

Antibody therapy in pancreatic cancer: mAb-ye we're onto something?

Pancreatic cancer remains an extremely deadly disease, with little improvement seen in treatment or outcomes over the last 40 years. Targeted monoclonal antibody therapy is one area that has been explored in attempts to tackle this disease. This review examines antibodies that have undergone clinical evaluation in pancreatic cancer. These antibodies target a wide variety of molecules, including tumour cell surface, stromal, immune and embryonic pathway targets. We discuss the therapeutic utility of these therapies both as monotherapeutics and in combination with other treatments such as chemotherapy. While antibody therapy for pancreatic cancer has yet to yield significant success, lessons learned from research thus far highlights future directions that may help overcome observed hurdles to yield clinically efficacious results.

Therapeutic Status and Available Strategies in Pancreatic Ductal Adenocarcinoma

One of the most severe and devastating cancer is pancreatic cancer. Pancreatic ductal adenocarcinoma (PDAC) is one of the major pancreatic exocrine cancer with a poor prognosis and growing prevalence. It is the most deadly disease, with an overall five-year survival rate of 6% to 10%. According to various reports, it has been demonstrated that pancreatic cancer stem cells (PCSCs) are the main factor responsible for the tumor development, proliferation, resistance to anti-cancer drugs, and recurrence of tumors after surgery. PCSCs have encouraged new therapeutic methods to be explored that can specifically target cancer cells. Furthermore, stem cells, especially mesenchymal stem cells (MSCs), are known as influential anti-cancer agents as they function through anti-inflammatory, paracrine, cytokines, and chemokine's action. The properties of MSCs, such as migration to the site of infection and host immune cell activation by its secretome, seem to control the microenvironment of the pancreatic tumor. MSCs secretome exhibits similar therapeutic advantages as a conventional cell-based therapy. Moreover, the potential for drug delivery could be enhanced by engineered MSCs to increase drug bioactivity and absorption at the tumor site. In this review, we have discussed available therapeutic strategies, treatment hurdles, and the role of different factors such as PCSCs, cysteine, GPCR, PKM2, signaling pathways, immunotherapy, and NK-based therapy in pancreatic cancer.

Fam83D promotes tumorigenesis and gemcitabine resistance of pancreatic adenocarcinoma through the Wnt/β-catenin pathway

BACKGROUND

Elevated expression of family with sequence similarity 83 member D (Fam83D) has been found in various cancers; however, its role in pancreatic adenocarcinoma (PDAC) remains unclear. The current study was designed to elucidate the roles of Fam83D in pancreatic cancer.

METHOD

The level of Fam83D was detected in PDAC tissues and adjacent no-tumorous tissues. Effects of Fam83D on proliferation, glycolysis and gemcitabine (GEM) sensitivity of pancreatic cancer cells were examined.

RESULTS

Fam83D was overexpressed in PDAC and associated with clinical stage, metastatic status and survival rates of PDAC patients. Function study showed that Fam83D knockdown (KD) caused inhibited proliferation, suppressed mitochondrial respiration capacity, reduced aerobic glycolysis, and down-regulation of nuclear β-catenin, proto-oncogene C-Myc, and lactate dehydrogenase A (LDHA). Fam83D KD enhanced the sensitivity of PDAC cells to GEM in vitro and in vivo. On the contrary, Fam83D overexpression displayed reverse effects on PDAC cells. Moreover, the Wnt/β-catenin inhibitor abolished the effects of Fam83D overexpression in PDAC cells.

CONCLUSIONS

the current data suggest that enhanced Fam83D expression contributes to PDAC progression and the development of chemoresistance through the Wnt/β-catenin signaling.

CMTM8 as an LPA1-associated partner mediates lysophosphatidic acid-induced pancreatic cancer metastasis

Background

Lysophosphatidic acid (LPA) is known to promote cancer cell invasiveness through LPA1, but the downstream signaling cascades are still not fully clarified. The CKLF-like MARVEL transmembrane domain-containing (CMTM) family regulates aggressive phenotype in many cancers.

Methods

We performed LPA1 co-immunoprecipitation combined with mass spectrometry to search for LPA1-associated proteins. The role of CMTM8 in mediating the pro-invasive activity of LPA was investigated in pancreatic cancer.

Results

We identified CMTM8 as an LPA1-interacting protein. LPA1 and CMTM8 were co-localized in pancreatic cancer cells. LPA treatment led to stabilization of CMTM8 protein, which was impaired by knockdown of LPA1. Depletion of CMTM8 significantly suppressed the migration and invasion of pancreatic cancer cells. Conversely, ectopic expression of CMTM8 enhanced the migratory and invasive capacity of pancreatic cancer cells. CMTM8 depletion blocked the formation of metastatic lesions in the lung. Knockdown of CMTM8 attenuated LPA-induced migration and invasion in pancreatic cancer cells. CMTM8 overexpression stimulated β-catenin activation through reduction of GSK3β. In addition, knockdown of β-catenin dramatically antagonized CMTM8-mediated migration and invasion in pancreatic cancer cells.

Conclusions

CMTM8 serves as a key mediator of LPA-induced invasiveness in pancreatic cancer. The interaction between CMTM8 and LPA1 leads to activation of oncogenic β-catenin signaling. CMTM8 represents a potential therapeutic target for pancreatic cancer.

Upregulation of DAB2IP Inhibits Ras Activity and Tumorigenesis in Human Pancreatic Cancer Cells

KRAS mutation-induced Ras activation plays an important role in the pathogenesis of pancreatic cancer, but the role of wild-type Ras and Ras GTPase-activating proteins remains unclear. The present study was designed to determine the expression spectra of Ras GTPase-activating proteins genes in pancreatic cancer cells, and the role of DAB2IP, a Ras GTPase-activating proteins gene, in the development and progression of pancreatic cancer. Following the analyses of the expression profiles of 16 Ras GTPase-activating proteins in 6 pancreatic cancer cell lines including Bxpc-3 (with wild-type KRAS), Capan-2, Sw1990, Aspc-1, CFPAC-1, and Panc-1 (with mutant KRAS) and 1 normal human pancreatic ductal epithelial cell line, H6C7, the expression of DAB2IP messenger RNA was further analyzed by quantitative real-time polymerase chain reaction. The role of DAB2IP in pancreatic cancer was further investigated in vitro and in vivo by upregulating DAB2IP in Bxpc-3 cells through transfection of DAB2IP into Bxpc-3 cells with recombinant lentivirus. The DAB2IP expression in pancreatic cancer cells and tissues with wild-type KRAS was significantly lower than that in cells and tissues with mutant KRAS (P < .05). In Bxpc-3 cells with wild-type KRAS, overexpression of DAB2IP decreased the expression of P-AKT and P-ERK and the Ras activity; increased the expression of P-JNK and caspase 3; inhibited cell proliferation, invasiveness, and migration; and increased the cell sensitivity to cetuximab. Overexpression of DAB2IP inhibited tumor progression in a mouse model. In conclusion, DAB2IP downregulates Ras activity in wild-type pancreatic cancer cells. Overexpression of DAB2IP decreases the Ras activity, inhibits cell proliferation, and increases sensitivity to cetuximab in wild-type pancreatic cancer cells. In conclusion, DAB2IP may serve as a potential molecular therapeutic target for the treatment of pancreatic cancer.

The Canonical Wnt Signaling (Wnt/β-Catenin Pathway): A Potential Target for Cancer Prevention and Therapy

Precise regulation of signal transduction pathways is crucial for normal animal development and for maintaining cellular and tissue homeostasis in adults. The Wnt/Frizzled-mediated signaling includes canonical and non-canonical signal transduction pathways. Upregulation or downregulation of the canonical Wnt signaling (or the Wnt/β-Catenin signal transduction) leads to a variety of human diseases, including cancers, neurodegenerative disorders, skin and bone diseases, and heart deficiencies. Therefore, Wnt/β-Catenin signal transduction is a potential clinical target for the treatment of not only human cancers but also some other human chronic diseases. Here, some recent results including those from my laboratory highlighting the role of Wnt/β-Catenin signal transduction in human cancers will be reviewed. After a brief overview on canonical Wnt signaling and introducing some critical β-Catenin/T-cell factor-target genes, the interaction of canonical Wnt signaling with some common human cancers will be discussed. In the end, the different segments of the aforesaid signaling pathway, which have been considered as targets for clinical purposes, will be scrutinized.

Antiproliferative Effects of Monoclonal Antibodies against (Pro)Renin Receptor in Pancreatic Ductal Adenocarcinoma

We previously reported that silencing of the PRR gene, which encodes the (pro)renin receptor [(P)RR], significantly reduced Wnt/β-catenin-dependent development of pancreatic ductal adenocarcinoma (PDAC). Here, we examined the effects of a panel of blocking mAbs directed against the (P)RR extracellular domain on proliferation of the human PDAC cell lines PK-1 and PANC-1 in vitro and in vivo We observed that four rat anti-(P)RR mAbs induced accumulation of cells in the G₀-G₁-phase of the cell cycle and significantly reduced proliferation in vitro concomitant with an attenuation of Wnt/β-catenin signaling. Systemic administration of the anti-(P)RR mAbs to nude mice bearing subcutaneous PK-1 xenografts significantly decreased tumor expression of active β-catenin and the proliferation marker Ki-67, and reduced tumor growth. In contrast, treatment with the handle region peptide of (pro)renin did not inhibit tumor growth in vitro or in vivo, indicating that the effects of the anti-(P)RR mAbs were independent of the renin-angiotensin system. These data indicate that mAbs against human (P)RR can suppress PDAC cell proliferation by hindering activation of the Wnt/β-catenin signaling pathway. Thus, mAb-mediated (P)RR blockade could be an attractive therapeutic strategy for PDAC.

CYR61/CCN1 expression in resected pancreatic ductal adenocarcinoma: A retrospective pilot study of the interaction between the tumors and their surrounding microenvironment

BACKGROUND

CCN1 is an extracellular matrix-associated protein thought to be implicated in tumor-stromal interaction in several solid tumors. The aim of our pilot study was to evaluate the correlation between CCN1 expression in stromal cells, pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma cells in resected pancreatic ductal adenocarcinoma (PDAC) specimens, and correlate that clinically.

METHODS

A total of 42 paraffin-embedded PDAC tumor specimens were stained for CCN1 and evaluated via immunohistochemical (IHC) analysis. Statistical analysis was performed to correlate between CCN1 expression profiles in tumor tissues and clinicopathological parameters of patients.

RESULTS

Our results showed CCN1 (CYR61) gene was highly expressed in PDAC tissues relative to other organ specific tumor tissues. Also, moderate and overexpression of CCN1 in PanIN was associated with PanIN grade 3 tissues. A statistically significant association was found between PanIN CCN1 scores on one hand and cancer stage, cancer grade, and CCN1 expression among ductal tumor cells and adjacent stromal cells on the other hand.

DISCUSSION

The associations demonstrated suggest that CCN1 might be contributing to a substantial role in the interaction between the pancreatic tumors on one hand and their surrounding microenvironment and their precursors on the other hand; hence, it might serve as a potential therapeutic target for PDAC.

WNT and β-Catenin in Cancer: Genes and Therapy

The WNT pathway is a pleiotropic signaling pathway that controls developmental processes, tissue homeostasis, and cancer. The WNT pathway is commonly mutated in many cancers, leading to widespread research into the role of WNT signaling in carcinogenesis. Understanding which cancers are reliant upon WNT activation and which components of the WNT signaling pathway are mutated is paramount to advancing therapeutic strategies. In addition, building holistic insights into the role of WNT signaling in not only tumor cells but also the tumor microenvironment is a vital area of research and may be a promising therapeutic strategy in multiple immunologically inert cancers. Novel compounds aimed at modulating the WNT signaling pathway using diverse mechanisms are currently under investigation in preclinical/early clinical studies. Here, we review how the WNT pathway is activated in multiple cancers and discuss current strategies to target aberrant WNT signaling.

The Benzimidazole-Based Anthelmintic Parbendazole: A Repurposed Drug Candidate That Synergizes with Gemcitabine in Pancreatic Cancer

Pancreatic cancer (PC) is one of the most lethal, chemoresistant malignancies and it is of paramount importance to find more effective therapeutic agents. Repurposing of non-anticancer drugs may expand the repertoire of effective molecules. Studies on repurposing of benzimidazole-based anthelmintics in PC and on their interaction with agents approved for PC therapy are lacking. We analyzed the effects of four Food and Drug Administration (FDA)-approved benzimidazoles on AsPC-1 and Capan-2 pancreatic cancer cell line viability. Notably, parbendazole was the most potent benzimidazole affecting PC cell viability, with half maximal inhibitory concentration (IC₅₀) values in the nanomolar range. The drug markedly inhibited proliferation, clonogenicity and migration of PC cell lines through mechanisms involving alteration of microtubule organization and formation of irregular mitotic spindles. Moreover, parbendazole interfered with cell cycle progression promoting G2/M arrest, followed by the emergence of enlarged, polyploid cells. These abnormalities, suggesting a mitotic catastrophe, culminated in PC cell apoptosis, are also associated with DNA damage in PC cell lines. Remarkably, combinations of parbendazole with gemcitabine, a drug employed as first-line treatment in PC, synergistically decreased PC cell viability. In conclusion, this is the first study providing evidence that parbendazole as a single agent, or in combination with gemcitabine, is a repurposing candidate in the currently dismal PC therapy.

New therapeutic targets in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is associated with poor survival. Of all newly diagnosed patients, only about 20% can benefit from a potentially curative surgical resection, the remaining 80% presenting with unresectable locally advanced (LAPC) or metastatic (MPC) disease. Currently, there are limited therapeutic options for LAPC and MPC patients. Furthermore, despite intensive research efforts to better understand the molecular bases of PDAC and the biological relevance of its tumor microenvironment, treatments still largely consist of classical cytotoxic chemotherapy agents. Several studies of genetic and epigenetic sequencing have demonstrated the existence of 4 molecular PDAC subtypes, with heterogeneous genetic characteristics and different biological behaviour: squamous, pancreatic progenitor, immunogenic and aberrantly differentiated endocrine exocrine (ADEX). These distinct subtypes derive from alterations at multiple levels. Apart from the DNA repair pathway, however, none of these has so far been validated as a clinically relevant therapeutic target. Also, PDAC is unique from an immunological perspective and many studies have recently tried to elucidate the role of intratumoral effector T-cells, RAS oncogene, immunosuppressive leukocytes and desmoplastic reaction in maintaining the immunological homeostasis of this disease. However, there still remains much to be learned about the mechanisms whereby the pancreatic immune microenvironment promotes immune escape of cancer cells. Furthermore, while therapies targeting the stroma as well as immunotherapies hold promise for the future, these are not yet standard of care. This review aims to outline the state-of-the-art of LAPC and MPC treatment, highlighting data on the target therapies failure and current ongoing clinical trials on new promising therapeutic strategies.

Indirubin 3'-Oxime Inhibits Migration, Invasion, and Metastasis InVivo in Mice Bearing Spontaneously Occurring Pancreatic Cancer via Blocking the RAF/ERK, AKT, and SAPK/JNK Pathways

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with high invasive and metastatic potential. We generated a spontaneous PDAC mouse model and examined the therapeutic potential of indirubin 3'-oxime (Indox) against PDAC bearing mouse in vivo.

METHODS

Randomized 3-month-old LSL-Kras^G12D/+;Trp53^flox/+;Pdx-1-cre (KPC^flox) mice were intraperitoneally injected with 40 mg/kg Indox (n = 9) or a vehicle (n = 10) twice a week. At the end point, tumor status including proliferation, direct invasion, and distant metastasis was analyzed histopathologically. The inhibitory potentials of Indox for proliferation, migration/invasion, and the phosphorylation of target molecules were determined in KPC^flox-derived PDAC cells in vitro.

RESULTS

Prolonged survival by Indox via intraperitoneal administration was observed in the KPC^flox mice. Indox inhibited tumor proliferation accompanied with low levels of nuclear phosphorylated cyclin-dependent kinase (p-CDK) and cyclin B1 in vivo. Furthermore, Indox inhibited the migration/invasive activities of PDAC via down-regulation of matrix metalloproteinase (MMP)-9 in vitro and in vivo. Antibody array and immunoblotting analysis revealed that Indox inhibited the phosphorylation of multiple molecules, including key upstream proteins of MMP-9 in RAF/extracellular signal-regulated kinase (ERK), AKT, and stress-activated protein kinase/c-Jun-N-terminal kinase (SAPK/JNK) pathways.

CONCLUSION

Indox inhibited the proliferative, invasive, and metastatic potentials of PDAC in vitro and in vivo. Therefore, Indox could a therapeutic candidate for treating spontaneously occurring PDAC via blocking the RAF/ERK, AKT and SAPK/JNK pathways.

USP21 deubiquitinase promotes pancreas cancer cell stemness via Wnt pathway activation

The ubiquitin-specific protease (USP) family is the largest group of cysteine proteases. Cancer genomic analysis identified frequent amplification of USP21 (22%) in human pancreatic ductal adenocarcinoma (PDAC). USP21 overexpression correlates with human PDAC progression, and enforced expression of USP21 accelerates murine PDAC tumor growth and drives PanIN to PDAC progression in immortalized human pancreatic ductal cells. Conversely, depletion of USP21 impairs PDAC tumor growth. Mechanistically, USP21 deubiquitinates and stabilizes the TCF/LEF transcription factor TCF7, which promotes cancer cell stemness. Our work identifies and validates USP21 as a PDAC oncogene, providing a potential druggable target for this intractable disease.

Circular RNA expression in pancreatic ductal adenocarcinoma

The regulatory roles of circular RNAs (circRNAs) in cancer are attracting increasing attention. The aim of the present study was to explore the roles of circRNAs in pancreatic ductal adenocarcinoma (PDAC) using microarray data. The circRNA and microRNA (miRNA) microarray data were downloaded from Gene Expression Omnibus. A total of 256 differentially expressed circRNAs were obtained by analyzing the circRNA microarray data from 26 pairs of PDAC and adjacent normal tissues. Differentially expressed miRNAs were analyzed using a dataset of 6 PDAC tissues and 5 non-neoplastic pancreas samples (GSE43796); 20 differentially expressed miRNAs were detected. circRNA/miRNA interactions were predicted between differentially expressed circRNAs and miRNAs using miRanda and RNAhybrid algorithms and 51 circRNA/miRNA interactions were obtained. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis using gene symbols of differentially expressed circRNAs demonstrated that 41 circRNAs were enriched in 17 pathways. Subnetworks that were associated with apoptosis or proliferation were extracted from the 17 pathways and a new network was constructed using Cytoscape software, which identified that mitogen-activated protein kinase, PI3K/AKT and WNT/β-catenin signaling pathways may be associated with PDAC development. In conclusion, 256 differentially expressed circRNAs and 20 differentially expressed miRNAs were identified in PDAC tissues compared with normal tissues; the circRNA/miRNA interactions and the networks of KEGG pathways provided a global view of the function of these differentially expressed circRNAs and miRNAs.

The Insulin-Like Growth Factor 2 mRNA Binding Protein IMP2/IGF2BP2 is Overexpressed and Correlates with Poor Survival in Pancreatic Cancer

The insulin-like growth factor 2 (IGF2) mRNA binding protein IMP2 (IGF2BP2) is an oncogenic protein known to be overexpressed in different tumor types. Pancreatic cancer is a very lethal cancer that requires early diagnosis and new treatment options. The aim of our study was to investigate the role of IMP2 in the initiation and progression of pancreatic ductal adenocarcinoma (PDAC). IMP2 was significantly overexpressed in a human precursor (PanIN) lesions suggesting IMP2 as a marker for early stages of PDAC. In a PDAC cohort of matched normal and tumor samples IMP2 showed overexpression in tumor tissues compared with normal pancreatic tissue. Strict correlation analysis (threshold R² > 0.75) revealed 22 genes highly positively and 9 genes highly negatively correlating with IMP2. Besides genes involved in the inhibition of apoptosis (Bcl-XL), especially factors involved in ubiquitination were strongly correlated with IMP2 expression: SMURF1 and FBXO45. Moreover, protein kinase C (PKC) signaling pathway was distinctly affected: DXS1179E encoding PKC iota, PKC substrate PLEK2, and inositol triphosphate receptor IP3R3 were positively correlated with IMP2 expression. Besides tumor initiation, IMP2 also seemed to have an impact on tumor progression. TGF-β treatment of Panc-1 pancreatic cancer cells to induce epithelial-mesenchymal transition (EMT) was accompanied by increased IMP2 expression. EMT is important for cancer cells to gain migratory and invasive potential, which is essential for metastasis. Concordantly, circulating tumor cells showed higher IMP2 levels as compared with normal tissue from tumor origin and with normal hematological cells. Accordingly, IMP2 protein levels correlated with poor survival. In conclusion, as IMP2 seems to promote tumor progression of PDAC, it might be an interesting diagnostic and prognostic marker as well as a novel target for the treatment of PDAC.

Therapeutic potential of targeting the Wnt/β-catenin pathway in the treatment of pancreatic cancer

The Wnt/β-catenin pathway is an important, dysregulated pathway in several tumor types, including pancreatic ductal adenocarcinoma. Although the activation of this pathway is an important component of normal development, its aberrant activation resulting from activating or inactivating mutations in the CTNNB1 gene locus, or in the negative regulators AXIN and APC involving stabilization of β-catenin, and activation of target genes leads to a more aggressive phenotype, suggesting its potential value as a therapeutic target in the treatment of pancreatic ductal adenocarcinoma. A number of small molecule and biologic agents have now been developed for targeting this pathway. This review summarizes the current knowledge about the therapeutic potential of targeting the Wnt pathway with particular emphasis on preclinical/clinical studies in the treatment of pancreatic ductal adenocarcinoma.

Wnt/β-catenin signalling plays diverse functions during the process of fibrotic remodelling in the exocrine pancreas

BACKGROUND/OBJECTIVES

Wnt/β-catenin signalling plays vital roles in tissue homeostasis. Dysregulation of the pathway has been implicated in the pathogenesis of cancer and fibroses in numerous tissues, including the pancreas. We studied the effect of microenvironmental changes pertaining to fibrotic tissue remodelling on the expression of selected Wnt/β-catenin pathway proteins in the human exocrine pancreas. The role of acinar/stellate cross-talk on the expression of the proteins was elucidated in a long-term mouse co-culture system.

METHODS

Expression of β-catenin, Wnt2, Wnt5a and SFRP4 was analysed immunohistochemically in normal and moderately or highly fibrotic human pancreata (n = 8). The effect of humoral interactions on the expression of the proteins was studied by immunocytochemical means in parallel mono- and co-cultures of mouse acinar and stellate cells (PSCs).

RESULTS

In human pancreatic tissue, fibrotic microenvironment was associated with redistribution of the proteins in and between epithelial and stromal compartments, compared to acinar-rich tissue. In non-fibrotic and moderately fibrotic tissue the proteins appeared only in acinar cells whereas in highly fibrotic tissue stromal fibroblastoid/stellate cells and macrophages were their predominant locations. Subcellular changes in the expression of β-catenin and Wnt5a were detected. Our in vitro data suggest potential involvement of acinar cell/PSC cross-talk in mediating the changes observed in tissue specimens.

CONCLUSIONS

Wnt/β-catenin pathway-associated proteins are abundantly expressed in the exocrine pancreas with prominent changes in their cellular and subcellular expression patterns along with increasing levels of fibrosis. Diverse functions for Wnt/β-catenin signalling during the course of fibrotic remodelling in the exocrine pancreas are suggested.

Downregulation of miR-142-5p promotes tumor metastasis through directly regulating CYR61 expression in gastric cancer

BACKGROUND

Recurrence is a primary cause of gastric cancer (GC)-related deaths. We reported previously that low expression of miR-142-5p could predict recurrence in GC. The present study aimed to investigate the function and mechanism of miR-142-5p in metastasis of GC.

METHODS

MiR-142-5p expression was detected in 101 GC samples by qRT-PCR. Its clinical significance was statistically analyzed. The roles of miR-142-5p and its candidate target gene CYR61 in metastasis were determined both in vivo and in vitro.

RESULTS

MiR-142-5p downregulation was significantly associated with the recurrence (P = 0.031) and poor prognosis of GC (P = 0.043). MiR-142-5p inhibited cancer cell migration and invasion both in vitro and in vivo. CYR61 was identified as a novel direct target of miR-142-5p by bioinformatics analysis of target prediction and luciferase reporter assay. The re-expression and knockdown of CYR61 could, respectively, rescue the effects induced by miR-142-5p overexpression and knockdown. MiR-142-5p attenuated GC cell migration and invasion, at least partially, by inactivation of the canonical Wnt/β-catenin signaling pathway through CYR61.

CONCLUSIONS

The newly identified miR-142-5p-CYR61-Wnt/β-catenin axis partially illustrates the molecular mechanism of GC recurrence and represents a novel prognosis biomarker for GC.

Blocking CXCLs-CXCR2 axis in tumor-stromal interactions contributes to survival in a mouse model of pancreatic ductal adenocarcinoma through reduced cell invasion/migration and a shift of immune-inflammatory microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is characterized by dense stromal reaction (desmoplasia). We have previously reported that mice with conditional KrasG12D mutation and knockout of TGF-β receptor type II (Tgfbr2), PKF mice, develop PDAC with desmoplasia modulated by CXC chemokines that are produced by PDAC cells through tumor-stromal interaction. In this study, we further discovered that PDAC and cancer-associated fibroblast (CAF) accelerated each other's invasion and migration through the CXC chemokines-receptor (CXCLs-CXCR2) axis. Heterozygous knockout of Cxcr2 in PKF mice (PKF2h mice) prolonged survival and inhibited both tumor angiogenesis and PDAC microinvasion. Infiltration of neutrophils, myeloid-derived suppressor cells (MDSCs), and arginase-1+ M2-like tumor-associated macrophages (TAMs) significantly decreased in the tumors of PKF2h mice, whereas inducible nitric oxide synthase (iNOS)+ M1-like TAMs and apoptotic tumor cells markedly increased, which indicated that blockade of the CXCLs-CXCR2 axis resulted in a shift of immune-inflammatory microenvironment. These results suggest that blocking of the CXCLs-CXCR2 axis in tumor-stromal interactions could be a therapeutic approach against PDAC progression.

Translational molecular imaging in exocrine pancreatic cancer

Effective treatment for pancreatic cancer remains challenging, particularly the treatment of pancreatic ductal adenocarcinoma (PDAC), which makes up more than 95% of all pancreatic cancers. Late diagnosis and failure of chemotherapy and radiotherapy are all too common, and many patients die soon after diagnosis. Here, we make the case for the increased use of molecular imaging in PDAC preclinical research and in patient management.

Role of Wnt/β-catenin pathway agonist SKL2001 in Caerulein-induced acute pancreatitis

The goal of this study was to clarify the protective role of the Wnt/β-catenin pathway agonist SKL2001 in a rat model of Caerulein-induced acute pancreatitis. AR42J cells and rats were divided into 4 groups: control, Caerulein, SKL2001 + Caerulein, and SKL2001 + control. Cell apoptosis was examined using flow cytometry. Hematoxylin-eosin staining was performed to observe pathological changes in pancreatic and small intestinal tissues. Inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA), while genes related to the Wnt/β-catenin pathway were quantified using quantitative real-time PCR. In vitro results showed that Caerulein promoted cell necrosis, inhibited the Wnt/β-catenin pathway, and increased the level of inflammatory cytokines. However, SKL2001 reduced cell necrosis and inflammatory cytokines and activated the Wnt/β-catenin pathway. Additionally, in vivo results demonstrated the accumulation of fluid (i.e., edema), hemorrhage, inflammation and necrosis of the pancreatic acini occurred 6 h after the final Caerulein induction, with the damage reaching a maximal level 12 h after the final Caerulein induction; meanwhile, the Wnt/β-catenin pathway was evidently inhibited with an enhanced level of inflammatory cytokines. The aforementioned damage was further aggravated 12 h later. Nevertheless, the pancreatic and small intestinal tissue damages were alleviated in Caerulein-induced rats treated with SKL2001. In conclusion, activation of the Wnt/β-catenin pathway could inhibit Caerulein-induced cell apoptosis and inflammatory cytokine release, thus improving pancreatic and intestinal damage in rats with acute pancreatitis.

MicroRNA-661 expression is upregulated in pancreatic ductal adenocarcinoma and promotes cell proliferation

Deregulation of microRNA (miRNA/miR) expression has been implicated in the development of pancreatic ductal adenocarcinoma (PDAC). However, the role of miR-661 in PDAC remains unknown. In the present study, it was revealed that miR-661 expression was significantly upregulated in PDAC tissues compared with that in adjacent normal tissues by using reverse transcription-quantitative polymerase chain reaction assays. Higher miR-661 expression revealed a positive association with lymph node metastasis, an advanced T stage and a poor prognosis in patients with PDAC. Furthermore, ectopic expression of miR-661 significantly promoted the cell proliferation ability in PDAC cell lines, and simultaneously promoted Wnt signaling pathway-related protein expression of β-catenin, transcription factor 4 and cyclin D1 in vitro. However, the downregulation of miR-661 revealed reverse effects. Thus, the results of the present study indicated that miR-661 may function as a prognostic marker and provide insight for pancreatic cancer treatment.

Polymorphisms of the CYR61 gene in patients with acute myeloid leukemia in a Han Chinese population

It was demonstrated in previous studies that cysteine-rich angiogenic inducer 61 (Cyr61) plays vital roles in hematological disorders, and we have already reported that the Cyr61 protein is a tumor promoter in acute myeloid leukemia (AML). Here, we investigated the association between CYR61 gene polymorphisms and susceptibility to AML.We genotyped 2 single-nucleotide polymorphisms (rs2297141 and rs6576776) in the region of the CYR61 gene by improved multiplex ligase detection reaction genotyping assays in a total of 275 samples, including samples from 137 AML patients and 138 healthy controls. Chi-squared tests and logistic regression analysis were performed to compare the different distributions of the genotypes and alleles between patients and healthy controls.The rs2297141 A allele was associated with lower risk of AML compared with the G allele (odds ratio [OR] = 0.704, 95% confidence interval [CI] = 0.503-0.985, P = .04) in both the dominant (OR = 0.447, 95% CI = 0.22-0.909, P = .025, AA vs GG) and recessive inheritance models (OR = 0.419, 95% CI = 0.23-0.763, P = .004, AA vs GA + GG). Although the distribution of the rs6576776 alleles was not different between patients with AML and normal controls, the CC genotype significantly increased the risk of AML in the dominant inheritance model (OR = 6.064, 95% CI = 1.303-28.216, P = .01, CC vs GG) and the recessive inheritance model (OR = 5.937, 95% CI = 1.291-27.306, P = .01, CC vs GC + GG). Additionally, it was shown that the rs2297141 and rs6576776 genotypes were associated with AML-M5 and AML-M2, respectively.Our findings indicated that genetic polymorphisms in the CYR61 gene may be considered potential AML risk factors in the Han Chinese population.

Developmentally regulated signaling pathways in glioma invasion

Malignant gliomas are the most common, infiltrative, and lethal primary brain tumors affecting the adult population. The grim prognosis for this disease is due to a combination of the presence of highly invasive tumor cells that escape surgical resection and the presence of a population of therapy-resistant cancer stem cells found within these tumors. Several studies suggest that glioma cells have cleverly hijacked the normal developmental program of neural progenitor cells, including their transcriptional programs, to enhance gliomagenesis. In this review, we summarize the role of developmentally regulated signaling pathways that have been found to facilitate glioma growth and invasion. Furthermore, we discuss how the microenvironment and treatment-induced perturbations of these highly interconnected signaling networks can trigger a shift in cellular phenotype and tumor subtype.

DACT1 overexpression inhibits proliferation, enhances apoptosis, and increases daunorubicin chemosensitivity in KG-1α cells

DACT1 has been shown to participate in the development of many types of tumors; however, its role and precise molecular mechanisms in leukemia are unclear. In this study, we investigated the effect of DACT1 on KG-1α leukemia cells to further understand the mechanisms of DACT1-mediated tumor suppression. We transfected a DACT1 expression plasmid to upregulate DACT1 in KG-1α cells and analyzed the resulting phenotypic changes. The results demonstrated that DACT1 overexpression inhibited KG-1α proliferation, increased apoptosis, and arrested cells in the G0/G1 phase. Mechanistically, DACT1 overexpression inhibited Wnt/β-catenin signaling by reducing nuclear β-catenin levels in KG-1α cells. Furthermore, the viability of KG-1α cells transfected with DACT1 was significantly reduced when treated with daunorubicin. We also found that DACT1 reduced P-glycoprotein expression in KG-1α cells. These findings revealed an inhibitory role for DACT1 in leukemogenesis and provided evidence that DACT1 is an attractive target for the development of novel anti-leukemia therapies.

MEK inhibitor, PD98059, promotes breast cancer cell migration by inducing β-catenin nuclear accumulation

Abnormal activation of the RAF/MEK/ERK signaling pathway has been observed in breast cancer. Thus, a number of MEK inhibitors have been designed as one treatment option for breast cancer. Although some studies have found that these MEK inhibitors inhibit the growth of a variety of human cancer cells, some trials have shown that the use of MEK inhibitors as a treatment for breast cancer does not adequately improve survival for unknown reasons. In the present study, MEK inhibitor PD98059 was used to evaluate its anticancer effects on human breast cancer MCF-7 and MDA-MB-231 cells and to explore the possible mechanism of action. Our results revealed that MEK inhibitor PD98059 exhibited antiproliferative effects in a dose- and time-dependent manner in MCF-7 and MDA-MB-231 breast cancer cells. Conversely, incubation of MCF-7 and MDA-MB-231 cells with PD98059 promoted their migration. Further investigation disclosed that the enhanced ability of migration promoted by PD98059 was dependent on β-catenin nuclear translocation in the MCF-7 and MDA-MB‑231 cells. Subsequent experiments documented that activation of EGFR signaling induced by PD98059 increased the amount of β-catenin in the nucleus. Taken together, our findings may elucidate a possible mechanism explaining the ineffectiveness of MEK inhibitors in breast cancer treatment and improve our understanding of the role of MEK in cancer.

ZNF281 Promotes Growth and Invasion of Pancreatic Cancer Cells by Activating Wnt/β-Catenin Signaling

BACKGROUND

Zinc finger protein 281 (ZNF281) has been identified to be involved in embryonic stem cell differentiation and tissue development. Also, ZNF281 was found in various types of cancers. However, its biological functions and clinical significance in pancreatic cancer remain elusive.

AIMS

To explore the role of ZNF281 in pancreatic cancer cells proliferation and invasion.

METHODS

ZNF281 expression was examined in public database Oncomine and cBioPortal. The correlation between ZNF281 and clinicopathological features was measured, and Kaplan-Meier method was used to measure the overall survival and recurrence-free survival in the TCGA cohort. Ectopic expression and knockdown of ZNF281 were performed to measure the impact on cell proliferation and invasion. Western blot and immunoprecipitation were further used to identify the ZNF281 interacting proteins. Topflash luciferase assay was used to detect the Wnt/β-catenin signaling activation.

RESULTS

ZNF281 was predominantly up-regulated in pancreatic cancer tissues and significantly associated with advanced stage. Meanwhile, the high expression of ZNF281 indicated shorter overall survival and recurrence-free survival and ZNF281 could be an independent prognostic factor of pancreatic cancer. ZNF281 promoted cell proliferation and invasion in vitro. Mechanically, ZNF281 activated Wnt/β-catenin signaling and induced the downstream gene expression by directly binding with β-catenin and decreasing the polyubiquitination.

CONCLUSIONS

ZNF281 promotes pancreatic cancer cells proliferation and invasion by interacting and up-regulating β-catenin, highlighting the role of ZNF281 in pancreatic cancer progression.

Distinct prognostic values of alcohol dehydrogenase mRNA expression in pancreatic adenocarcinoma

Background

Alcohol dehydrogenase (ADH) isoenzymes have been reported as a potential diagnostic marker for pancreatic cancer, but their prognostic value in pancreatic cancer remains unclear. The aim of this investigation was to identify the prognostic value of ADH genes in human patients with pancreatic adenocarcinoma (PAAD).

Materials and methods

An RNA sequencing dataset and corresponding survival profiles of PAAD were obtained from The Cancer Genome Atlas. Survival analysis and gene set enrichment analysis were used to investigate the prediction value and potential mechanism of ADH genes in PAAD prognosis.

Results

Survival analysis of ADH genes suggests that a high expression of ADH1A (adjusted P=0.037, adjusted hazard ratio [HR] =0.627, 95% CI =0.404–0.972) and ADH6 (adjusted P=0.018, adjusted HR =0.588, 95% CI =0.378–0.914) were associated with a significantly decreased risk of death, while a high expression of ADH5 was associated with a significantly increased risk of death (adjusted P=0.043, adjusted HR =1.564, 95% CI =1.013–2.414). Joint effects analysis of three ADH gene prognostic markers suggests that the prognosis difference for any marker combination was more significant than that for any individual marker. The potential mechanism of ADH1A and ADH6 in PAAD prognosis was that a high expression of ADH1A and ADH6 was involved in the P450 pathway and biological processes, while high ADH5 expression was involved in transforming growth factor β regulation-related pathways and biological processes, Wnt, the cell cycle, ErbB, and mitogen-activated protein kinase signaling pathways.

Conclusion

Our data suggest that ADH1A, ADH5, and ADH6 expression may be potential prognostic markers of PAAD and in combination have a strong interaction and better predictive value for PAAD prognosis.

Use of Angiotensin System Inhibitors Is Associated with Immune Activation and Longer Survival in Nonmetastatic Pancreatic Ductal Adenocarcinoma

Purpose: Angiotensin system inhibitors (ASI) can improve prognosis in multiple cancer types, including pancreatic ductal adenocarcinoma (PDAC). However, no study has examined the effect of ASIs alone or combined with adjuvant chemotherapy in resected PDAC patients.Experimental Design: We performed an analysis of the records of ASI users and nonuser patients with PDAC seen at Massachusetts General Hospital (Boston, MA) between January 2006 and December 2010. To identify mechanisms of ASIs in PDAC, we performed RNA sequencing (RNA-Seq) of resected primary lesions.Results: A total of 794 consecutive patients were included. In 299 resected patients, ASI users experienced longer overall survival (OS) in both univariate (median OS, 36.3 vs. 19.3 months, P = 0.011) and adjusted multivariate [HR, 0.505; 95% confidence interval (CI), 0.339-0.750; P = 0.001] analyses. Propensity score-adjusted analysis also showed a longer median OS for chronic ASI users. In unresected patients, the beneficial effect of ASIs was significant in patients with locally advanced disease, but not in metastatic patients. RNA-Seq analysis revealed in tumors of ASI users (lisinopril) a normalized extracellular matrix, a reduced expression of genes involved in PDAC progression (e.g., WNT and Notch signaling), and an increased expression of genes linked with the activity of T cells and antigen-presenting cells. Finally, chronic use of ASI was associated with a gene expression signature that is predictive of survival in independent validation cohorts.Conclusions: In patients with nonmetastatic PDAC, chronic ASI use is associated with longer OS independently of chemotherapy. Our RNA-Seq analysis suggests that ASIs reduce the malignant potential of cancer cells and stimulate the immune microenvironment in primary PDAC. Clin Cancer Res; 23(19); 5959-69. ©2017 AACR.

Induction of cell death in pancreatic ductal adenocarcinoma by indirubin 3'-oxime and 5-methoxyindirubin 3'-oxime in vitro and in vivo

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a poor prognosis. To identify potential effective therapeutic drugs for PDAC, we established a screening system based on spheroid formation using 170#3 mouse PDAC cells with or without fibroblasts. We found that indirubin 3'-oxime (Indox) and 5-methoxyindirubin 3'-oxime (5MeOIndox) inhibited PDAC cell proliferation. Furthermore, PDAC xenograft growth was also inhibited in BALB/c nu/nu mice after administration of Indox and 5MeOIndox. Both phosphorylated CDK1 and cyclin B1 levels in 170#3 cells were significantly reduced by treatment with Indox and 5MeOIndox in vitro and in vivo. Cell cycle analysis revealed that 5MeOIndox, but not Indox, induced G2/M arrest. Annexin V-propidium iodide double-staining analysis demonstrated that Indox induced abundant non-apoptotic cell death of 170#3 cells, while 5MeOIndox predominantly induced early apoptosis, indicating that the cytotoxicity of 5MeOIndox is lower than that of Indox. These results suggest that one mechanism of 5MeOIndox is to induce G2/M arrest of PDAC cells via inhibition of CDK1/cyclin B1 levels, thereby leading to apoptosis. Our findings suggest 5MeOIndox as a potential useful anticancer agent in PDAC.