Clinical Pancreatic Cancer Samples Research Articles

Enhanced tumoricidal activity of PD-1 antibody-secreting c-Met CAR-T cells against pancreatic cancer cells

To construct c-Met CAR-T cells secreting PD-1 antibodies to reduce immune inhibitory effect of tumor cells and enhance the efficacy of CAR-T cell therapy against pancreatic cancer. Kaplan-Meier Plotter, GEPIA, and Timer 2.0 bioinformatics databases were used to analyze c-Met expression in pancreatic cancer and its correlation with survival and immune infiltration status. In clinical samples of pancreatic cancer and pancreatic cancer Aspc-1 cells, c-Met and PD-L1 expressions were detected using immunohistochemistry or flow cytometry. Using gene editing technology, PD-1 secretory antibodies and HIS tags were linked to second-generation c-Met CAR molecules to construct PD-1/c-Met CAR plasmids, which were then packaged into lentiviruses for infection of activated T cells. The positive rate and cell subset distribution of CAR-T cells were analyzed with flow cytometry, and secretory PD-1 antibodies in cell supernatants were detected using Western blotting. The target cell killing efficiency and proliferative activity of the modified CAR-T cells were evaluated after activation, and cytokine secretion was analyzed using ELISA. The expression of c-Met was significantly higher in pancreatic cancer than in normal tissues, and its expression level was negatively correlated with the patients' survival and positively correlated with immune cell infiltration. The clinical samples of pancreatic cancer tissues expressed significantly higher levels of c-Met and PD-L1 than the adjacent tissues, and 90.7% and 57.7% of Aspc-1 cells were positive for c-Met and PD-L1, respectively. The constructed PD-1/c-Met CAR-T cells were capable of secreting PD-1 antibodies and showed a significantly higher killing efficiency against tumor cells than c-Met CAR-T cells at an effector-to-target ratio of 20: 1, with also a higher proliferative activity after target cell stimulation and higher levels of IL-2 and TNF-α secretin. PD-1/c-Met CAR-T cells have higher killing efficiency against pancreatic cancer cells with also higher proliferative activity than c-Met CAR-T cells.

HTF4 modulates the transcription of GID2 to promote the malignant biological behavior of pancreatic cancer

BackgroundHelix-loop-helix transcription factor 4 (HTF4) as an anti-cancer target has been reported in many human cancers, but limited data exists regarding the effect of HTF4 in pancreatic cancer. In this study, we aimed to investigate the role of HTF4 in pancreatic cancer. MethodsThe expression levels of HTF4 in clinical pancreatic cancer samples were measured. HTF4 was knocked down or overexpressed in pancreatic cancer cells and was subsequently tested for bio-function using in vitro assays and in vivo. The regulation of HTF4 on GID2 was assessed via bioinformatic tools and dual-luciferase reporter assay. ResultsWe found that HTF4 was highly expressed in pancreatic cancer tissues and correlated with poor patient prognosis. In addition, knocking down HTF4 expression inhibited cell proliferation, migration, and invasion, whereas HTF4 overexpression exerted the opposite effect. Moreover, HTF4 promoted tumor growth and metastasis in pancreatic cancer. Further, HTF4 bound to the GID2 promoter region and promoted transcriptional activation of GID2 in pancreatic cancer cells. GID2 knockdown suppressed HTF4-induced malignant behaviors of pancreatic cancer cells. ConclusionsOur findings suggest that the HTF4/GID2 axis accelerates the progression of pancreatic cancer, providing a potential therapeutic target and prognostic indicator for the treatment of pancreatic cancer patients.

Development of Dual Diagnostic-Therapeutic Nanoformulation Effective Against Pancreatic Cancer in Animal Model.

Erythrocytes and fibroblasts in the pancreatic cancer tumor microenvironment promote tumor cell growth and invasion by providing nutrients and promoting immunosuppression. Additionally, they form a barrier against the penetration of chemotherapeutic drugs. Therefore, the search for diversified tumor-targeting materials plays an essential role in solving the above problems. Physicochemical characterization of Graphene fluorescent nanoparticles (GFNPs) and nanomedicines were analyzed by transmission electron microscopy (TEM), elemental analyzers and ultraviolet fluorescence (UV/FL) spectrophotometer. Localization of GFNPs in cell and tissue sections imaged with laser confocal microscope, fluorescence scanner and small animal in vivo imager. Qualitative detection and quantitative detection of GFNPs and GFNPs-GEM were performed using High performance liquid chromatography (HPLC). Based on the 3 nm average dimensions, GFNPs penetrate vascular endothelial cells and smooth muscle cells, achieve up to label 30% tumor cells and 60% cancer-associated fibroblasts (CAFs) cells, and accurately label mature red blood cells in the tumor microenvironment. In orthotopic transplanted pancreatic cancer models, the fluorescence intensity of GFNPs in tumors showed a positive correlation with the cycle size of tumor development. The differential spatial distribution of GFNPs in three typical clinical pancreatic cancer samples demonstrated their diagnostic potential. To mediate the excellent targeting properties of GFNPs, we synthesized a series of nanomedicines using popular chemotherapeutic drugs, in which complex of GFNPs and gemcitabine (GFNPs-GEM) possessed stability in vivo and exhibited effective reduction of tumor volume and fewer side effects. GFNPs with multiple targeting tumor microenvironments in pancreatic cancer possess diagnostic efficiency and therapeutic potential.

GID2 Interacts With CDKN3 and Regulates Pancreatic Cancer Growth and Apoptosis

Dysregulation of deubiquitinase or ubiquitinase-mediated protein expression contributes to various diseases, including cancer. In the present study, we identified GID2, a subunit of the glucose-induced degradation-deficient (GID) complex that functions as an E3 ubiquitin ligase, as a potential key candidate gene in pancreatic cancer (PC) progression. The functional role and potential mechanism of GID2 in PC progression were investigated. Integrated bioinformatics analysis was performed to identify differentially expressed genes in PC based on the Gene Expression Profiling Interactive Analysis data sets. We found that GID2 was upregulated in PC tissues and that a high level of GID2 expression in clinical PC samples was positively associated with tumor stage and poor survival. Functional assays elucidated that GID2 expression promoted cell growth in vitro and accelerated tumor growth in vivo. GID2 knockdown effectively attenuated the malignant behaviors of PC cells and tumor formation. Furthermore, the protein network that interacted with the GID2 protein was constructed based on the GeneMANIA website. Cyclin-dependent kinase inhibitor 3 (CDKN3), a cell cycle regulator, was identified as a potential target of the GID2 protein. We revealed that GID2 positively regulated CDKN3 expression and inhibited CDKN3 ubiquitination. Furthermore, CDKN3 downregulation reversed the promoting effects of GID2 on PC progression. Therefore, the present study demonstrated that GID2 might regulate PC progression by maintaining the stability of the CDKN3 protein. These findings highlight the potential roles of the GID2/CDKN3 axis as a potential therapeutic target in PC.

Probe Synthesis Reveals Eukaryotic Translation Elongation Factor 1 Alpha 1 as the Anti-Pancreatic Cancer Target of BE-43547A2.

The natural product, BE-43547A2 , decreases pancreatic cancer cell stemness. However, its anticancer molecular mechanisms have not been fully established. Based on structure-activity relationships of BE-43547A2 , we synthesized a probe and investigated its potential targets using an in situ click reaction. We found that BE-43547A2 exerts its anticancer effects by covalently binding the cysteine234 (C234) residue of eukaryotic translation elongation factor 1 alpha 1 (eEF1A1). This binding mode was confirmed by a series of experiments including a xenograft mouse model. We also determined that eEF1A1 plays an important role in regulating pancreatic cancer cell stemness. Analyses of 99 clinical pancreatic cancer samples revealed that eEF1A1 expressions are closely correlated with clinicopathological grade and patient survival. In conclusion, eEF1A1 is involved in pancreatic cancer progression and is therefore, a promising novel covalent target for pancreatic cancer treatment.

Probe Synthesis Reveals Eukaryotic Translation Elongation Factor 1 Alpha 1 as the Anti‐Pancreatic Cancer Target of BE‐43547A2

AbstractThe natural product, BE‐43547A2, decreases pancreatic cancer cell stemness. However, its anticancer molecular mechanisms have not been fully established. Based on structure–activity relationships of BE‐43547A2, we synthesized a probe and investigated its potential targets using an in situ click reaction. We found that BE‐43547A2 exerts its anticancer effects by covalently binding the cysteine234 (C234) residue of eukaryotic translation elongation factor 1 alpha 1 (eEF1A1). This binding mode was confirmed by a series of experiments including a xenograft mouse model. We also determined that eEF1A1 plays an important role in regulating pancreatic cancer cell stemness. Analyses of 99 clinical pancreatic cancer samples revealed that eEF1A1 expressions are closely correlated with clinicopathological grade and patient survival. In conclusion, eEF1A1 is involved in pancreatic cancer progression and is therefore, a promising novel covalent target for pancreatic cancer treatment.

Abstract 235: Differential polyamine expression in human pancreatic cancer supports the use of polyamine blockade therapy to modulate the in vivo pancreatic tumor microenvironment

Abstract Pancreatic cancer has a poor five-year survival rate of less than 8% and is projected to be the second leading cause of cancer related deaths in the US by the year 2030. Polyamine metabolism is an underexplored therapeutic target in pancreatic ductal adenocarcinoma (PDAC). The current investigation profiled RNA expression of genes associated with polyamine metabolism, transport and homeostasis in clinical pancreatic cancer samples to reveal evidence for dysregulation of polyamine-based pathways in PDAC. Increased expression of select pro-polyamine genes was associated with poorer patient prognosis in data obtained from the TCGA dataset. Preclinical experimental data supported the use of polyamine blockade therapy (PBT) in pancreatic tumor bearing mice, and revealed that PBT increased survival and decreased tumor weights in comparison to control treatment. PBT therapeutic effects were associated with increased expression of CD86 T cell co-stimulatory marker present on antigen presenting cells in the tumor microenvironment. Collectively, polyamine dysregulation in human pancreatic cancer is associated with poorer patient prognosis, whereas PBT treatment resulted in improved in vivo therapeutic outcomes in part through immune modulation in the tumor microenvironment. Citation Format: Sai Preethi Nakkina, Sarah B. Gitto, Veethika Pandey, Jignesh Parikh, Dirk Geerts, Carlo Maurer, Kenneth P. Olive, Otto Phanstiel, Deborah A. Altomare. Differential polyamine expression in human pancreatic cancer supports the use of polyamine blockade therapy to modulate the in vivo pancreatic tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 235.

KRAS variant allele frequency, but not mutation positivity, associates with survival of patients with pancreatic cancer.

KRAS mutation is a major driver of pancreatic carcinogenesis and will likely be a therapeutic target. Due to lack of sensitive assays for clinical samples of pancreatic cancer with low cellularity, KRAS mutations and their prognostic association have not been fully examined in large populations. In a multi‐institutional cohort of 1162 pancreatic cancer patients with formalin‐fixed paraffin‐embedded tumor samples, we undertook droplet digital PCR (ddPCR) for KRAS codons 12/13/61. We examined detection rates of KRAS mutations by clinicopathological parameters and survival associations of KRAS mutation status. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for disease‐free survival (DFS) and overall survival (OS) were computed using the Cox regression model with adjustment for potential confounders. KRAS mutations were detected in 1139 (98%) patients. The detection rate did not differ by age of tissue blocks, tumor cellularity, or receipt of neoadjuvant chemotherapy. KRAS mutations were not associated with DFS or OS (multivariable HR comparing KRAS‐mutant to KRAS‐wild‐type tumors, 1.04 [95% CI, 0.62–1.75] and 1.05 [95% CI, 0.60–1.84], respectively). Among KRAS‐mutant tumors, KRAS variant allele frequency (VAF) was inversely associated with DFS and OS with HRs per 20% VAF increase of 1.27 (95% CI, 1.13–1.42; p trend <0.001) and 1.31 (95% CI, 1.16–1.48; p trend <0.001), respectively. In summary, ddPCR detected KRAS mutations in clinical specimens of pancreatic cancer with high sensitivity irrespective of parameters potentially affecting mutation detections. KRAS VAF, but not mutation positivity, was associated with survival of pancreatic cancer patients.

Calreticulin promotes EMT in pancreatic cancer via mediating Ca2+ dependent acute and chronic endoplasmic reticulum stress

BackgroundOur previous study showed that calreticulin (CRT) promoted EGF-induced epithelial-mesenchymal transition (EMT) in pancreatic cancer (PC) via Integrin/EGFR-ERK/MAPK signaling. We next investigated the novel signal pathway and molecular mechanism involving the oncogenic role of CRT in PC.MethodsWe investigated the potential role and mechanism of CRT in regulating intracellular free Ca2+ dependent acute and chronic endoplasmic reticulum stress (ERS)-induced EMT in PC in vitro and vivo.ResultsThapsigargin (TG) induced acute ERS via increasing intracellular free Ca2+ in PC cells, which was reversed by CRT silencing. Additionally, CRT silencing inhibited TG-induced EMT in vitro by reversing TG-induced changes of the key proteins in EMT signaling (ZO-1, E-cadherin and Slug) and ERK/MAPK signaling (pERK). TG-promoted cell invasion and migration was also rescued by CRT silencing but enhanced by IRE1α silencing (one of the key stressors in unfolded protein response). Meanwhile, CRT was co-immunoprecipitated and co-localized with IRE1α in vitro and its silencing led to the chronic ERS via upregulating IRE1α independent of IRE1-XBP1 axis. Moreover, CRT silencing inhibited IRE1α silencing-promoted EMT, including inhibiting the activation of EMT and ERK/MAPK signaling and the promotion of cell mobility. In vivo, CRT silencing decreased subcutaneous tumor size and distant liver metastasis following with the increase of IRE1α expression. A negative relationship between CRT and IRE1α was also observed in clinical PC samples, which coordinately promoted the advanced clinical stages and poor prognosis of PC patients.ConclusionsCRT promotes EMT in PC via mediating intracellular free Ca2+ dependent TG-induced acute ERS and IRE1α-mediated chronic ERS via Slug and ERK/MAPK signaling.

&lt;p&gt;CPA4 Promotes EMT in Pancreatic Cancer via Stimulating PI3K-AKT-mTOR Signaling&lt;/p&gt;

BackgroundCarboxypeptidase A4 (CPA4), as a novel tumor biomarker, is prevalently observed in various cancers. However, the potential role of CPA4 in pancreatic cancer (PC), to our knowledge, has not been fully clarified.Materials and MethodsWe systematically explored the detailed function of CPA4 in epithelial to mesenchymal transition (EMT) stimulated PC in human clinical samples and in vitro.ResultsCPA4 was overexpressed in clinical PC samples that was positively related with tumor size (P=0.026), T stage (P=0.011), lymph-node metastasis (P=0.026) and a worse prognosis for PC patients (P=0.001). Interestingly, CPA4 was inversely correlated with E-cadherin (r=−0.372, P=0.003) in clinical samples and PC cell lines which cooperatively contributed to a worse prognosis (P=0.005) for PC patients. CPA4 overexpression enhanced EMT in AsPC-1 and Capan-2 cells, which promoted EMT-like cellular morphology and cell invasion and migration. Meanwhile, CPA4 overexpression activated EMT and PI3K-AKT-mTOR signaling, following with the downregulation of E-cadherin and β-catenin, and the upregulation of N-cadherin, vimentin, p-PI3K (Tyr458), p-AKT (Ser473) and p-mTOR (Ser2448). However, PI3K inhibitor LY294002 reversed CPA4 overexpression-stimulated EMT in vitro. Moreover, CPA4 was co-immunoprecipitated with AKT in two PC cells with CPA4 high expression. Conversely, CPA4 silencing inhibited EMT in PANC-1 cells. CPA4 overexpression or silencing promoted or inhibited cell proliferation and drug resistance in Capan-2 and PANC-1 cells via regulating Bcl2/Bax and cleaved-caspase3 signaling. However, LY294002 reversed CPA4 overexpression-stimulated cell proliferation and drug resistance in vitro in Bcl2/Bax and caspase3-dependent apoptosis.ConclusionCPA4 overexpression contributes to aggressive clinical stage of PC patients and promotes EMT in vitro via activation of PI3K-AKT-mTOR signaling.

Upregulation of DLC-1 inhibits pancreatic cancer progression: Studies with clinical samples and a pancreatic cancer model.

Deleted in liver cancer 1 (DLC-1) serves a vital role in the progression of multiple cancers, including those of the pancreas. Numerous studies have aimed to reveal the anti-cancer mechanisms of the DLC-1 gene, though few have focused on its impact on the development of pancreatic cancer. Using clinical pancreatic cancer samples and pancreatic cancer cell lines, the present study aimed to reveal the role of DLC-1 in this disease. The expression levels of DLC-1 were determined in pancreatic cancer and adjacent normal tissues from patients with pancreatic cancer, indicating a decreased expression level of DLC-1 in cancerous tissues. Using the pancreatic cancer cell line SW1990, the effect of DLC overexpression on cell proliferation, invasive capacity and the cell cycle and were assessed. Using a mouse tumor model, the tumor-progression capacity of transfected and untransfected SW1990 cells was investigated, indicating that DLC-1 transfection reduced the capacity for tumor progression. Thus, the present study indicated that the overexpression of DLC-1 inhibited the proliferation and reduced the invasive capacity of SW1990 cells both in vitro and in vivo, and that it may have significant inhibitory effects on the development of pancreatic cancer.

Expression profile of tRNA-derived fragments in pancreatic cancer.

Pancreatic cancer is a deadly disease, the deadliest of all the solid tumors; the 5-year survival rate of patients with this disease is ~8%. Previously, high-throughput sequencing has led to the discovery of novel small non-coding RNAs, also known as transfer RNA-derived fragments (tRFs). Studies have suggested that tRFs may be novel biomarkers for certain diseases. However, the expression of tRFs in pancreatic cancer has yet to be characterized. In the present study, the expression levels of tRFs observed in clinical pancreatic cancer samples were analyzed, quantitative PCR (qPCR) was performed to validate the tRFs expression levels and bioinformatics predictions were analyzed. The results revealed that the pancreatic cancer samples screened out a total of 48 tRFs and transfer RNA halves (tiRNAs). There were four tRFs and tiRNAs selected for qPCR validation; the findings were consistent with the sequencing results. Bioinformatic predictions revealed that AS-tDR-000064 was predicted to have 2,450 target genes; AS-tDR-000069 was predicted 445 target genes; AS-tDR-000102 was predicted 746 target genes; and AS-tDR-001391 was predicted 216 target genes. Gene Ontology (GO) analyses demonstrated that the target genes of AS-tDR-000064 were mostly enriched in ‘the regulation of cellular processes’ (Biological Process), ‘the synapses’ (Cellular Component) and ‘enzyme binding’ (Molecular Function). The target genes of AS-tDR-000069 were mostly enriched in ‘signaling’ (Biological Process), ‘the plasma membrane’ (Cellular Component) and ‘phosphatidylinositol 3-kinase (PI3K) binding’(Molecular Function), the target genes of AS-tDR-000102 were mostly enriched in ‘axon development’ (Biological Process), ‘the synapse’ (Cellular Component) and ‘sequence-specific DNA binding’ (Molecular Function) and the target genes of AS-tDR-001391 were mostly enriched in ‘the neuromuscular processes’ (Biological Process), the neurons’ (Cellular Component) and ‘PDZ domain binding’ (Molecular Function). The Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the target genes of AS-tDR-000064 were mostly enriched in ‘the Ras signaling pathway’, the target genes of AS-tDR-000069 were mostly enriched in ‘the cancer pathways’, the target genes of AS-tDR-000102 were mostly enriched in ‘axon guidance’ and the target genes of AS-tDR-001391 were mostly enriched in ‘the PI3K/protein kinase-B signaling pathway’.

Nutrient Stress-Dysregulated Antisense lncRNA GLS-AS Impairs GLS-Mediated Metabolism and Represses Pancreatic Cancer Progression.

Cancer cells are known to undergo metabolic reprogramming, such as glycolysis and glutamine addiction, to sustain rapid proliferation and metastasis. It remains undefined whether long noncoding RNAs (lncRNA) coordinate the metabolic switch in pancreatic cancer. Here we identify a nuclear-enriched antisense lncRNA of glutaminase (GLS-AS) as a critical regulator involved in pancreatic cancer metabolism. GLS-AS was downregulated in pancreatic cancer tissues compared with noncancerous peritumor tissues. Depletion of GLS-AS promoted proliferation and invasion of pancreatic cancer cells both in vitro and in xenograft tumors of nude mice. GLS-AS inhibited GLS expression at the posttranscriptional level via formation of double stranded RNA with GLS pre-mRNA through ADAR/Dicer-dependent RNA interference. GLS-AS expression was transcriptionally downregulated by nutrient stress-induced Myc. Conversely, GLS-AS decreased Myc expression by impairing the GLS-mediated stability of Myc protein. These results imply a reciprocal feedback loop wherein Myc and GLS-AS regulate GLS overexpression during nutrient stress. Ectopic overexpression of GLS-AS inhibited proliferation and invasion of pancreatic cancer cells by repressing the Myc/GLS pathway. Moreover, expression of GLS-AS and GLS was inversely correlated in clinical samples of pancreatic cancer, while low expression of GLS-AS was associated with poor clinical outcomes. Collectively, our study implicates a novel lncRNA-mediated Myc/GLS pathway, which may serve as a metabolic target for pancreatic cancer therapy, and advances our understanding of the coupling role of lncRNA in nutrition stress and tumorigenesis.Significance: These findings show that lncRNA GLS-AS mediates a feedback loop of Myc and GLS, providing a potential therapeutic target for metabolic reprogramming in pancreatic cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/7/1398/F1.large.jpg.See related commentary by Mafra and Dias, p. 1302.

MicroRNA-634 functions as a tumor suppressor in pancreatic cancer via directly targeting heat shock-related 70-kDa protein 2.

Pancreatic cancer (PC) is one of the most malignant types of human cancer and has an extremely poor prognosis. MicroRNAs (miRs) reportedly serve a critical role in pancreatic ductal adenocarcinoma (PDAC) progression. Understanding the expression patterns and functions of miRs may provide strategies for the diagnosis and treatment of patients with PC. In particular, miR-634 is attracting interest due to its critical role in regulating the biology of some types of cancer. However, the expression patterns, biological function and molecular mechanism of miR-634 in PC remain unknown. In the present study, miR-634 expression levels in PC tissues and cell lines were significantly downregulated. Notably, the ectopic overexpression of miR-634 in PC cells inhibited tumor progression, whereas miR-634 silencing reversed these effects. Furthermore, reverse transcription-quantitative polymerase chain reaction, western blot analysis and the dual-luciferase assay revealed that miR-634 regulated heat shock-related 70 kDa protein 2 (HSPA2) by directly binding to its 3-untranslated region. In clinical samples of PC, miR-634 was inversely correlated with HSPA2, which was upregulated in PC. In the rescue experiment, HSPA2 overexpression partially abrogated the effects of miR-634 mimicry on biological function. In conclusion, miR-634 functioned as a tumor suppressor in regulating PC progression by targeting HSPA2 and may therefore be a novel potential therapeutic target for PC.

MicroRNA-137 reduces stemness features of pancreatic cancer cells by targeting KLF12

BackgroundCancer stem cells (CSCs) play an important role in the development of pancreatic cancer. We previously showed that the microRNA miR-137 is downregulated in clinical samples of pancreatic cancer, and its expression negatively regulates the proliferation and invasiveness of pancreatic cancer cells.MethodsThe stemness features of pancreatic cancer cells was detected by flow cytometry, immunofluorescence and sphere formation assay. Xenograft mouse models were used to assess the role of miR-137 in stemness features of pancreatic cancer cells in vivo. Dual-luciferase reporter assays were used to determine how miR-137 regulates KLF12. Bioinformatics and Chromatin immunoprecipitation analysis of KLF12 recruitment to the DVL2 promoters. Involvement of the Wnt/β-catenin pathways was investigated by western blot and Immunohistochemistry.ResultsmiR-137 inhibits pancreatic cancer cell stemness in vitro and vivo. KLF12 as miR-137 target inhibits CSC phenotype in pancreatic cancer cells. Suppression of KLF12 by miR-137 inhibits Wnt/β-catenin signalling. KLF12 expression correlates with DVL2 and canonical Wnt pathway in clinical pancreatic cancer.ConclusionOur results suggest that miR-137 reduces stemness features of pancreatic cancer cells by Targeting KLF12-associated Wnt/β-catenin pathways and may identify new diagnostic and therapeutic targets in pancreatic cancer.

Hypoxia-induced LncRNA-BX111 promotes metastasis and progression of pancreatic cancer through regulating ZEB1 transcription.

The contribution of long noncoding RNAs (lncRNAs) to pancreatic cancer progression and the regulatory mechanisms of their expression are attractive areas. In the present study, the overexpression of lncRNA-BX111887 (BX111) in pancreatic cancer tissues was detected by microarray and further validated in a cohort of pancreatic cancer tissues. We further demonstrated that knockdown or overexpression of BX111 dramatically repressed or enhanced proliferation and invasion of pancreatic cancer cells. Mechanically, BX111 activated transcription of ZEB1, a key regulator for epithelia-mesenchymal transition (EMT), via recruiting transcriptional factor Y-box protein (YB1) to its promoter region. Moreover, we revealed that BX111 transcription was induced by hypoxia-inducible factor (HIF-1α) in response to hypoxia. In addition, BX111 contributed to the hypoxia-induced EMT of pancreatic cells by regulating expression of ZEB1 and its downstream proteins E-cadherin and MMP2. Coincidence with in vitro results, BX111 depletion effectively inhibited growth and metastasis of xenograft tumor in vivo. The clinical samples of pancreatic cancer further confirmed a positive association between BX111 and ZEB1. Moreover, high BX111 expression was correlated with late TNM stage, lymphatic invasion and distant metastasis, as well as short overall survival time in patients. Taken together, our findings implicate a hypoxia-induced lncRNA contributes to metastasis and progression of pancreatic cancer, and suggest BX111 might be applied as a potential biomarker and therapeutic target for pancreatic cancer.

Molecular subtype specific efficacy of MEK inhibitors in pancreatic cancers.

Pancreatic cancer is an increasing cause of cancer related death worldwide. KRAS is the dominant oncogene in this cancer type and molecular rationale would indicate, that inhibitors of the downstream target MEK could be appropriate targeted agents, but clinical trials have failed so far to achieve statistically significant benefit in unselected patients. We aimed to identify predictive molecular biomarkers that can help to define subgroups where MEK inhibitors might be beneficial alone or in combination. Next-generation sequencing data of 50 genes in three pancreatic cancer cell lines (MiaPaCa2, BxPC3 and Panc1) were analyzed and compared to the molecular profile of 138 clinical pancreatic cancer samples to identify the molecular subtypes of pancreatic cancer these cell lines represent. Luminescent cell viability assay was used to determine the sensitivity of cell lines to kinase inhibitors. Western blot was used to analyze the pathway activity of the examined cell lines. According to our cell viability and pathway activity data on these model cell lines only cells harboring the rare G12C KRAS mutation and low EGFR expression are sensitive to single MEK inhibitor (trametinib) treatment. The common G12D KRAS mutation leads to elevated baseline Akt activity, thus treatment with single MEK inhibitors fails. However, combination of MEK and Akt inhibitors are synergistic in this case. In case of wild-type KRAS and high EGFR expression MEK inhibitor induced Akt phosphorylation leads to trametinib resistance which necessitates for MEK and EGFR or Akt inhibitor combination treatment. In all we provide strong preclinical rational and possible molecular mechanism to revisit MEK inhibitor therapy in pancreatic cancer in both monotherapy and combination, based on molecular profile analysis of pancreatic cancer samples and cell lines. According to our most remarkable finding, a small subgroup of patients with G12C KRAS mutation may still benefit from MEK inhibitor monotherapy.

BRM/SMARCA2 promotes the proliferation and chemoresistance of pancreatic cancer cells by targeting JAK2/STAT3 signaling

BackgroundBRM is one of two evolutionarily conserved catalytic ATPase subunits of SWI/SNF complexes and plays important role in cell proliferation, linage specification and development, cell adhesion, cytokine responses and DNA repair. BRM is often inactivated in various types of cancer indicating its indispensable roles in oncogenesis but the mechanisms remain poorly understood. MethodsBRM expression in clinical pancreatic cancer samples was examined by immunohistochemistry and the correlation with patient survival was analyzed. shRNAs targeting BRM were used to establish stable BRM knockdown BxPC-3 and T3M4 cell lines. Cell viability was assessed by CCK-8 assay. Cell proliferation was measured by EdU incorporation assay, colony formation assay and Ki67 staining. Cell cycle and apoptosis were examined by flow cytometry. Growth and chemosensitivity of xenografts initiating from BRM-deficient cells were evaluated, and in situ apoptosis was detected by TUNEL assay. The status of JAK-STAT3 signaling was examined by real-time PCR and Western blot analysis. ResultsHigh BRM expression was correlated with worse survival of pancreatic cancer patients. BRM shRNA reduced the proliferation and increased the sensitivity of pancreatic cancer cells to gemcitabine in vivo and in vitro, and these effects are associated with the inhibition of STAT3 phosphorylation and reduced transcription of STAT3 target genes. ConclusionWe reveal a novel mechanism by which BRM could activate JAK2/STAT3 pathway to promote pancreatic cancer growth and chemoresistance. These findings may offer potential therapeutic targets for pancreatic cancer patients with excessive BRM expression.

Tankyrase-Binding Protein TNKS1BP1 Regulates Actin Cytoskeleton Rearrangement and Cancer Cell Invasion

Tankyrase, a PARP that promotes telomere elongation and Wnt/β-catenin signaling, has various binding partners, suggesting that it has as-yet unidentified functions. Here, we report that the tankyrase-binding protein TNKS1BP1 regulates actin cytoskeleton and cancer cell invasion, which is closely associated with cancer progression. TNKS1BP1 colocalized with actin filaments and negatively regulated cell invasion. In TNKS1BP1-depleted cells, actin filament dynamics, focal adhesion, and lamellipodia ruffling were increased with activation of the ROCK/LIMK/cofilin pathway. TNKS1BP1 bound the actin-capping protein CapZA2. TNKS1BP1 depletion dissociated CapZA2 from the cytoskeleton, leading to cofilin phosphorylation and enhanced cell invasion. Tankyrase overexpression increased cofilin phosphorylation, dissociated CapZA2 from cytoskeleton, and enhanced cell invasion in a PARP activity-dependent manner. In clinical samples of pancreatic cancer, TNKS1BP1 expression was reduced in invasive regions. We propose that the tankyrase-TNKS1BP1 axis constitutes a posttranslational modulator of cell invasion whose aberration promotes cancer malignancy. Cancer Res; 77(9); 2328-38. ©2017 AACR.

YEATS4 promotes the tumorigenesis of pancreatic cancer by activating beta-catenin/TCF signaling.

Beta-catenin/TCF signaling has been reported to promote the growth and metastasis of pancreatic cancer cells. However, the regulation for the beta-catenin/TCF transcriptional complex remains largely unknown. Here, we have found that YEATS4 is a positive regulator for Beta-catenin/TCF signaling. The expression of YEATS4 was elevated in clinical pancreatic cancer samples and pancreatic cancer mouse model. Up-regulation of YEATS4 promoted the growth, migration and invasion of pancreatic cancer cells, while knocking down the expression of YEATS4 inhibited the growth, migration, invasion and metastasis of pancreatic cancer cells. Moreover, the mechanism study revealed that YEATS4 interacted with beta-catenin and activated beta-catenin/TCF signaling. Furthermore, knocking down the expression of YEATS4 impaired the malignant transformation of normal pancreatic cells (HPDE6C7) by the oncogenic Ras. Taken together, our study demonstrated the oncogenic roles of YEATS4 in the progression of pancreatic cancer by activating beta-catenin/TCF signaling and suggested that YEATS4 might be a promising therapeutic target for pancreatic cancer.