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The original version of this article unfortunately contained a mistake in the text of the entire article. The word “IL-39” should read as “meteorin-like protein”. This has been corrected with this correction.
Irinotecan is effective for the treatment of metastatic colorectal cancer (mCRC) and advanced pancreatic cancer (aPC). However, these treatments are often limited due to the incidence of severe neutropenia. We identified risk factors for severe neutropenia in patients with mCRC or aPC, receiving irinotecan-based chemotherapy regimens. The study selected 104 patients (mCRC: 53 and aPC: 51) who received irinotecan-based chemotherapy between January 2014 and May 2018 and who were included in the present study. The initial dose of irinotecan was 150 mg/m{sup 2} in all patients, and patients with a lower initial dose of irinotecan were excluded. Severe neutropenia (grade ≥ 3) occurred in 56 patients (53.8%). Multivariable Cox proportional hazards analysis indicated that modified FOLFIRINOX (mFOLFIRINOX) and serum total bilirubin (T-Bil) were significant risk factors for severe neutropenia. Moreover, with receiver-operating characteristic (ROC) curve analysis, the cutoff for T-Bil was found to be 0.7 mg/dL. Among patients treated with mFOLFIRINOX therapy, the incidence of severe neutropenia was significantly higher in patients with high level of T-Bil (> 0.7 mg/dL) than in those without it (93.8% vs 55.0%, P = 0.006). A chemotherapy regimen (modified FOLFIRINOX therapy) and T-Bil > 0.7 mg/dL were significant risk factors for severe neutropenia in patients receiving 150 mg/m{sup 2} irinotecan.
Nab-paclitaxel plus gemcitabine (Nab-Gem) represents one of the standard regimen for first-line treatment of metastatic pancreatic adenocarcinoma (mPDAC). However, few data are available in mPDAC relapsed after gemcitabine as adjuvant treatment. Our study aims to evaluate the efficacy and feasibility of Nab-Gem as first-line treatment for mPDAC patients previously treated with adjuvant treatment. We retrospectively analyzed the safety and efficacy data of 36 patients, who received first-line Nab-Gem after gemcitabine as adjuvant treatment. All patients received gemcitabine after radical surgery. Median disease-free survival was 12 months (95% CI 9.7–14.3); at relapse, all patients received Nab-Gem. We observed an objective response rate and disease control rate of 11.1% and 63.9%, respectively. With a median follow-up of 47 months, median progression-free survival was 5 months (95% CI 1.0–9.0), whereas median overall survival (OS) was 13 months (95% CI 5.5–20.5). Median OS was higher in patients with a relapse ≥ 7 months after the end of adjuvant treatment than in patients relapsed < 7 months (14 vs. 8 months, respectively, p: 0.52). Our results show that first-line Nab-Gem is feasible and effective in patients previously treated with gemcitabine as adjuvant treatment.
The majority of pancreatic cancers are diagnosed at an advanced stage, when surgical options are limited and treatment relies on systemic chemotherapy. In the NAPOLI-1 trial, liposomal irinotecan in combination with fluorouracil (nal-iri/5FU) was shown to improve overall survival when compared to fluorouracil alone for metastatic pancreatic cancer. Other retrospective studies have shown the combination of fluorouracil and conventional irinotecan (FOLFIRI) to be a viable option, though no randomized trials have compared nal-iri/5FU to FOLFIRI. The purpose of this single-center, retrospective, cohort study was to determine if nal-iri/5FU and FOLFIRI are similarly effective for the treatment of advanced pancreatic cancer. Due to the potential for treatment bias, inverse probability of treatment weighting was utilized to correct for baseline differences between the groups. The primary outcome of progression-free survival was similar at 4.1 months for nal-iri/5FU and 3.1 months for FOLFIRI. Overall survival and adverse effect frequency were also similar. Pegfilgrastim was used in 16% and 15% of patients, respectively, and nal-iri/5FU patients required significantly less atropine during treatment (36 vs. 70%). A cost analysis was conducted and concluded that the treatment with nal-iri/5FU was nearly 30 times more expensive than FOLFIRI treatment. Together, these data suggest a potential role for FOLFIRI for the treatment of advanced pancreatic cancer in the absence of clear benefits in effectiveness, toxicity, or cost for nal-iri/5FU.
Highlights: ► Cell-free synthesis system suitable for disulfide-containing proteins is proposed. ► Disulfide bond formation was facilitated by the use of glutathione buffer. ► DsbC catalyzed the efficient shuffling of incorrectly formed disulfide bonds. ► Milligram quantities of functional {sup 15}N-labeled BPTI and lysozyme C were obtained. ► Synthesized proteins were both catalytically functional and properly folded. -- Abstract: Many important therapeutic targets are secreted proteins with multiple disulfide bonds, such as antibodies, cytokines, hormones, and proteases. The preparation of these proteins for structural and functional analyses using cell-based expression systems still suffers from several issues, such as inefficiency, low yield, and difficulty in stable-isotope labeling. The cell-free (or in vitro) protein synthesis system has become a useful protein production method. The openness of the cell-free system allows direct control of the reaction environment to promote protein folding, making it well suited for the synthesis of disulfide-containing proteins. In this study, we developed the Escherichia coli (E. coli) cell lysate-based cell-free synthesis system for disulfide-containing proteins, which can produce sufficient amounts of functional proteins for NMR analyses. Disulfide bond formation was facilitated by the use of glutathione buffer. In addition, disulfide isomerase, DsbC, catalyzed the efficient shuffling of incorrectly formed disulfide bonds during the protein synthesis reaction. We successfully synthesized milligram quantities of functional {sup 15}N-labeled higher eukaryotic proteins, bovine pancreatic trypsin inhibitor (BPTI) and human lysozyme C (LYZ). The NMR spectra and functional analyses indicated that the synthesized proteins are both catalytically functional and properly folded. Thus, the cell-free system is useful for the synthesis of disulfide-containing proteins for structural and functional analyses.
Highlights: ► Emerging critical role for Gadd45α in modulating BER activity. ► Identifying specific PCNA binding site on Gadd45α protein. ► Regulating APE1 activity through interaction between Gadd45α and PCNA. ► Suggesting potential role of Gadd45α–PCNA binding in pancreatic carcinogenesis. -- Abstract: The growth arrest and DNA damage inducible, alpha (Gadd45α) protein regulates DNA repair by interacting with proliferating cell nuclear antigen (PCNA). Our previous study suggested a potential role for Gadd45α in the base excision repair (BER) pathway by affecting apurinic/apyrimidinic endonuclease 1 (APE1) protein in addition to its accepted role in nucleotide excision repair (NER). Here, we investigated whether the interaction of Gadd45α with PCNA affects APE1 activity. To address this issue, we used a siRNA directed to Gadd45α and a form of Gadd45α with a mutation to the predicted site of PCNA binding. There was a reduction of APE1 activity in cells transfected with the Gadd45α siRNA. Furthermore, the interaction of Gadd45α with PCNA and APE1 was lower in cells transfected with mutant Gadd45α compared with cells transfected with wild-type Gadd45α. Indeed, we observed that the APE1 activity in the Gadd45α-interacting complex was significantly lower in cells that overexpress mutant Gadd45α compared with cells that overexpress wild-type Gadd45α. We conclude that the PCNA binding site on Gadd45α plays a critical role in modulating the interaction with PCNA and APE1, affecting BER activity. These results provide novel insights into the mechanisms by which BER activity is modulated, although the interaction of Gadd45α with APE1 needs to be clarified.
Highlights: •Non-canonical roles of the myosin phosphatase inhibitor (CPI-17) were studied. •CPI-17 is localized in the nucleus of hyperplastic cancer and smooth muscle cells. •CPI-17 Ser12 phosphorylation may regulate the nuclear import. •CPI-17 regulates histone H3 phosphorylation and cell proliferation. •The nuclear CPI-17-PP1 axis plays a proliferative role in cells. -- Abstract: CPI-17 (C-kinase-activated protein phosphatase-1 (PP1) inhibitor, 17 kDa) is a cytoplasmic protein predominantly expressed in mature smooth muscle (SM) that regulates the myosin-associated PP1 holoenzyme (MLCP). Here, we show CPI-17 expression in proliferating cells, such as pancreatic cancer and hyperplastic SM cells. Immunofluorescence showed that CPI-17 was concentrated in nuclei of human pancreatic cancer (Panc1) cells. Nuclear accumulation of CPI-17 was also detected in the proliferating vascular SM cell culture and cells at neointima of rat vascular injury model. The N-terminal 21-residue tail domain of CPI-17 was necessary for the nuclear localization. Phospho-mimetic Asp-substitution of CPI-17 at Ser12 attenuated the nuclear import. CPI-17 phosphorylated at Ser12 was not localized at nuclei, suggesting a suppressive role of Ser12 phosphorylation in the nuclear import. Activated CPI-17 bound to all three isoforms of PP1 catalytic subunit in Panc1 nuclear extracts. CPI-17 knockdown in Panc1 resulted in dephosphorylation of histone H3 at Thr3, Ser10 and Thr11, whereas it had no effects on the phosphorylation of myosin light chain and merlin, the known targets of MLCP. In parallel, CPI-17 knockdown suppressed Panc1 proliferation. We propose that CPI-17 accumulated in the nucleus through the N-terminal tail targets multiple PP1 signaling pathways regulating cell proliferation.
Highlights: •Arnt mRNA expressed in a circadian manner in mouse pancreatic islets. •Expressions of Dbp and Arnt damped in the islets of a diabetic model mouse. •DBP and E4BP4 regulate Arnt promoter activity by direct binding. •Arnt may have a role in connecting circadian rhythm and metabolism. -- Abstract: Aryl hydrocarbon receptor nuclear translocator (ARNT)/hypoxia inducible factor-1β (HIF-1β) has emerged as a potential determinant of pancreatic β-cell dysfunction and type 2 diabetes in humans. An 82% reduction in Arnt expression was observed in islets from type 2 diabetic donors as compared to non-diabetic donors. However, few regulators of Arnt expression have been identified. Meanwhile, disruption of the clock components CLOCK and BMAL1 is known to result in hypoinsulinemia and diabetes, but the molecular details remain unclear. In this study, we identified a novel molecular connection between Arnt and two clock-controlled output genes, albumin D-element binding protein (Dbp) and E4 binding protein 4 (E4bp4). By conducting gene expression studies using the islets of Wfs1{sup −/−} A{sup y}/a mice that develop severe diabetes due to β-cell apoptosis, we demonstrated clock-related gene expressions to be altered in the diabetic mice. Dbp mRNA decreased by 50%, E4bp4 mRNA increased by 50%, and Arnt mRNA decreased by 30% at Zeitgever Time (ZT) 12. Mouse pancreatic islets exhibited oscillations of clock gene expressions. E4BP4, a D-box negative regulator, oscillated anti-phase to DBP, a D-box positive regulator. We also found low-amplitude circadian expression of Arnt mRNA, which peaked at ZT4. Over-expression of DBP raised both mRNA and protein levels of ARNT in HEK293 and MIN6 cell lines. Arnt promoter-driven luciferase reporter assay in MIN6 cells revealed that DBP increased Arnt promoter activity by 2.5-fold and that E4BP4 competitively inhibited its activation. In addition, on ChIP assay, DBP and E4BP4 directly bound to D-box elements within the Arnt promoter in MIN6 cells. These results suggest that in mouse pancreatic islets mRNA expression of Arnt fluctuates significantly in a circadian manner and that the down-regulation of Dbp and up-regulation E4bp4 contribute to direct suppression of Arnt expression in diabetes.
Highlights: •Belinostat activates AMPK in cultured pancreatic cancer cells. •Activation of AMPK is important for belinostat-induced cytotoxic effects. •ROS and TAK1 are involved in belinostat-induced AMPK activation. •AMPK activation mediates mTOR inhibition by belinostat. -- Abstract: Pancreatic cancer accounts for more than 250,000 deaths worldwide each year. Recent studies have shown that belinostat, a novel pan histone deacetylases inhibitor (HDACi) induces apoptosis and growth inhibition in pancreatic cancer cells. However, the underlying mechanisms are not fully understood. In the current study, we found that AMP-activated protein kinase (AMPK) activation was required for belinostat-induced apoptosis and anti-proliferation in PANC-1 pancreatic cancer cells. A significant AMPK activation was induced by belinostat in PANC-1 cells. Inhibition of AMPK by RNAi knockdown or dominant negative (DN) mutation significantly inhibited belinostat-induced apoptosis in PANC-1 cells. Reversely, AMPK activator AICAR and A-769662 exerted strong cytotoxicity in PANC-1 cells. Belinostat promoted reactive oxygen species (ROS) production in PANC-1 cells, increased ROS induced transforming growth factor-β-activating kinase 1 (TAK1)/AMPK association to activate AMPK. Meanwhile, anti-oxidants N-Acetyl-Cysteine (NAC) and MnTBAP as well as TAK1 shRNA knockdown suppressed belinostat-induced AMPK activation and PANC-1 cell apoptosis. In conclusion, we propose that belinostat-induced apoptosis and growth inhibition require the activation of ROS-TAK1-AMPK signaling axis in cultured pancreatic cancer cells.
Highlights: •Pancreatic cancer cells express low miR-143 levels and elevated p-MEK, p-MAPK and RREB1. •MEK inhibitors U0126 and PD98059 increase miR-143 expression. •miR-143 decreases COX-2 mRNA stability and expression and PGE{sub 2}. •miR-143 decreases p-p38MAPK, p-MEK, p-MAPK and RREB1 expression. -- Abstract: Small non-coding RNAs, microRNAs (miRNA), inhibit the translation or accelerate the degradation of message RNA (mRNA) by targeting the 3′-untranslated region (3′-UTR) in regulating growth and survival through gene suppression. Deregulated miRNA expression contributes to disease progression in several cancers types, including pancreatic cancers (PaCa). PaCa tissues and cells exhibit decreased miRNA, elevated cyclooxygenase (COX)-2 and increased prostaglandin E{sub 2} (PGE{sub 2}) resulting in increased cancer growth and metastases. Human PaCa cell lines were used to demonstrate that restoration of miRNA-143 (miR-143) regulates COX-2 and inhibits cell proliferation. miR-143 were detected at fold levels of 0.41 ± 0.06 in AsPC-1, 0.20 ± 0.05 in Capan-2 and 0.10 ± 0.02 in MIA PaCa-2. miR-143 was not detected in BxPC-3, HPAF-II and Panc-1 which correlated with elevated mitogen-activated kinase (MAPK) and MAPK kinase (MEK) activation. Treatment with 10 μM of MEK inhibitor U0126 or PD98059 increased miR-143, respectively, by 187 ± 18 and 152 ± 26-fold in BxPC-3 and 182 ± 7 and 136 ± 9-fold in HPAF-II. miR-143 transfection diminished COX-2 mRNA stability at 60 min by 2.6 ± 0.3-fold in BxPC-3 and 2.5 ± 0.2-fold in HPAF-II. COX-2 expression and cellular proliferation in BxPC-3 and HPAF-II inversely correlated with increasing miR-143. PGE{sub 2} levels decreased by 39.3 ± 5.0% in BxPC-3 and 48.0 ± 3.0% in HPAF-II transfected with miR-143. Restoration of miR-143 in PaCa cells suppressed of COX-2, PGE{sub 2}, cellular proliferation and MEK/MAPK activation, implicating this pathway in regulating miR-143 expression.
Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation.
Highlights: •A single extra copy of Dscr1 restrains progression of PanIN-1A to PanIN-1B lesions. •Dscr1 trisomy attenuates calcineurin–NFAT pathway in neoplastic ductal epithelium. •Dscr1 trisomy leads to upregulation of p15{sup INK4b} in neoplastic ductal epithelium. •A single extra copy of Dscr1 reduces epithelial proliferation in early PanIN lesions. •Dscr1 trisomy may protect Down syndrome individuals from pancreatic cancer. -- Abstract: Individuals with Down syndrome exhibit remarkably reduced incidence of most solid tumors including pancreatic cancer. Multiple mechanisms arising from the genetic complexity underlying Down syndrome has been suggested to contribute to such a broad cancer protection. In this study, utilizing a genetically engineered mouse model of pancreatic cancer, we demonstrate that trisomy of the Down syndrome critical region-1 (Dscr1), an endogenous calcineurin inhibitor localized on chromosome 21, suppresses the progression of pancreatic intraepithelial neoplasia-1A (PanIN-1A) to PanIN-1B lesions without affecting the initiation of PanIN lesions mediated by oncogenic Kras{sup G12D}. In addition, we show that Dscr1 trisomy attenuates nuclear localization of nuclear factor of activated T-cells (NFAT) accompanied by upregulation of the p15{sup Ink4b} tumor suppressor and reduction of cell proliferation in early PanIN lesions. Our data suggest that attenuation of calcineurin–NFAT signaling in neoplastic pancreatic ductal epithelium by a single extra copy of Dscr1 is sufficient to inhibit the progression of early PanIN lesions driven by oncogenic Kras, and thus may be a potential mechanism underlying reduced incidence of pancreatic cancer in Down syndrome individuals.
Highlights: •Overexpression of Ran in pancreatic cancer was correlated with histological grade. •Downregulation of Ran could induce cell apoptosis and inhibit cell proliferation. •The effects were mediated by cell cycle proteins, Survivin and cleaved Caspase-3. -- Abstract: Ran, a member of the Ras GTPase family, has important roles in nucleocytoplasmic transport. Herein, we detected Ran expression in pancreatic cancer and explored its potential role on tumour progression. Overexpressed Ran in pancreatic cancer tissues was found highly correlated with the histological grade. Downregulation of Ran led to significant suppression of cell proliferation, cell cycle arrest at the G1/S phase and induction of apoptosis. In vivo studies also validated that result. Further studies revealed that those effects were at least partly mediated by the downregulation of Cyclin A, Cyclin D1, Cyclin E, CDK2, CDK4, phospho-Rb and Survivin proteins and up regulation of cleaved Caspase-3.
Highlights: •Axl is overexpressed in a variety of cancers. •Axl overexpression confers invasive phenotype. •Axl imaging would be useful for therapeutic guidance and monitoring. •Axl expression imaging is demonstrated in pancreatic and prostate cancer xenografts. •Graded levels of Axl expression imaging is feasible. -- Abstract: The receptor tyrosine kinase Axl is overexpressed in and leads to patient morbidity and mortality in a variety of cancers. Axl–Gas6 interactions are critical for tumor growth, angiogenesis and metastasis. The goal of this study was to investigate the feasibility of imaging graded levels of Axl expression in tumors using a radiolabeled antibody. We radiolabeled anti-human Axl (Axl mAb) and control IgG1 antibodies with {sup 125}I with high specific radioactivity and radiochemical purity, resulting in an immunoreactive fraction suitable for in vivo studies. Radiolabeled antibodies were investigated in severe combined immunodeficient mice harboring subcutaneous CFPAC (Axl{sup high}) and Panc1 (Axl{sup low}) pancreatic cancer xenografts by ex vivo biodistribution and imaging. Based on these results, the specificity of [{sup 125}I]Axl mAb was also validated in mice harboring orthotopic Panc1 or CFPAC tumors and in mice harboring subcutaneous 22Rv1 (Axl{sup low}) or DU145 (Axl{sup high}) prostate tumors by ex vivo biodistribution and imaging studies at 72 h post-injection of the antibody. Both imaging and biodistribution studies demonstrated specific and persistent accumulation of [{sup 125}I]Axl mAb in Axl{sup high} (CFPAC and DU145) expression tumors compared to the Axl{sup low} (Panc1 and 22Rv1) expression tumors. Axl expression in these tumors was further confirmed by immunohistochemical studies. No difference in the uptake of radioactivity was observed between the control [{sup 125}I]IgG1 antibody in the Axl{sup high} and Axl{sup low} expression tumors. These data demonstrate the feasibility of imaging Axl expression in pancreatic and prostate tumor xenografts.
Highlights: •PKR can be activated by glucolipitoxicity and pro-inflammatory cytokines in β-cells. •Activated PKR inhibited β-cell proliferation by arresting cell cycle at G1 phase. •Activated PKR fully abrogated the pro-proliferative effects of IGF-I on β-cells. -- Abstract: Double-stranded RNA-dependent protein kinase (PKR) is revealed to participate in the development of insulin resistance in peripheral tissues in type 2 diabetes (T2DM). Meanwhile, PKR is also characterized as a critical regulator of cell proliferation. To date, no study has focused on the impact of PKR on the proliferation of pancreatic β-cells. Here, we adopted insulinoma cell lines and mice islet β-cells to investigate: (1) the effects of glucolipotoxicity and pro-inflammatory cytokines on PKR activation; (2) the effects of PKR on proliferation of pancreatic β-cells and its underlying mechanisms; (3) the actions of PKR on pro-proliferative effects of IGF-I and its underlying pathway. Our results provided the first evidence that PKR can be activated by glucolipitoxicity and pro-inflammatory cytokines in pancreatic β-cells, and activated PKR significantly inhibited cell proliferation by arresting cell cycle at G1 phase. Reductions in cyclin D1 and D2 as well as increases in p27 and p53 were associated with the anti-proliferative effects of PKR, and proteasome-dependent degradation took part in the reduction of cyclin D1 and D2. Besides, PKR activation abrogated the pro-proliferative effects of IGF-I by activating JNK and disrupting IRS1/PI3K/Akt signaling pathway. These findings indicate that the anti-proliferative actions of PKR on pancreatic β-cells may contribute to the pathogenesis of T2DM.
Highlights: •This research confirmed VMP1 as a regulator of autophagy in colorectal cancer cell lines. •We proved the pro-survival role of VMP1-mediated autophagy in colorectal cancer cell lines. •We found the interaction between VMP1 and BECLIN1 also existing in colorectal cancer cell lines. -- Abstract: Vacuole membrane protein 1 (VMP1) is an autophagy-related protein and identified as a key regulator of autophagy in recent years. In pancreatic cell lines, VMP1-dependent autophagy has been linked to positive regulation of apoptosis. However, there are no published reports on the role of VMP1 in autophagy and apoptosis in colorectal cancers. Therefore, to address this gap of knowledge, we decided to interrogate regulation of autophagy and apoptosis by VMP1. We have studied the induction of autophagy by starvation and rapamycin treatment in colorectal cell lines using electron microscopy, immunofluorescence, and immunoblotting. We found that starvation-induced autophagy correlated with an increase in VMP1 expression, that VMP1 interacted with BECLIN1, and that siRNA mediated down-regulation of VMP1-reduced autophagy. Next, we examined the relationship between VMP1-dependent autophagy and apoptosis and found that VMP1 down-regulation sensitizes cells to apoptosis and that agents that induce apoptosis down-regulate VMP1. In conclusion, similar to its reported role in other cell types, VMP1 is an important regulator of autophagy in colorectal cell lines. However, in contrast to its role in pancreatic cell lines, in colorectal cancer cells, VMP1-dependent autophagy appears to be pro-survival rather than pro-cell death.
Highlights: •K cells were selected from STC-1 cells, a heterogeneous enteroendocrine cell line. •K cells did not express Nkx6.1 and Neurogenin3. •Combined expression of Nkx6.1 and Neurogenin3 reprogrammed K cells to β-cells. •Reprogramming of K cells to β-cells was not complete. -- Abstract: Recent studies have demonstrated that adult cells such as pancreatic exocrine cells can be converted to pancreatic β-cells in a process called cell reprogramming. Enteroendocrine cells and β-cells share similar pathways of differentiation during embryonic development. Notably, enteroendocrine K cells express many of the key proteins found in β-cells. Thus, K cells could be reprogrammed to β-cells under certain conditions. However, there is no clear evidence on whether these cells convert to β-cells. K cells were selected from STC-1 cells, an enteroendocrine cell line expressing multiple hormones. K cells were found to express many genes of transcription factors crucial for islet development and differentiation except for Nkx6.1 and Neurogenin3. A K cell clone stably expressing Nkx6.1 (Nkx6.1{sup +}-K cells) was established. Induction of Neurogenin3 expression in Nkx6.1{sup +}-K cells, by either treatment with a γ-secretase inhibitor or infection with a recombinant adenovirus expressing Neurogenin3, led to a significant increase in Insulin1 mRNA expression. After infection with the adenovirus expressing Neurogenin3 and reaggregation in suspension culture, about 50% of Nkx6.1{sup +}-K cells expressed insulin as determined by immunostaining. The intracellular insulin content was increased markedly. Electron microscopy revealed the presence of insulin granules. However, glucose-stimulated insulin secretion was defective, and there was no glucose lowering effect after transplantation of these cells in diabetic mice. In conclusion, we demonstrated that K cells could be reprogrammed partially to β-cells through the combined expression of Nkx6.1 and Neurogenin3, and reaggregation in suspension culture.
Highlights: • CypA is upregulated in experimental pancreatitis. • CCK induces expression and release of CypA in acinar cell in vitro. • rCypA aggravates CCK-induced acinar cell death and inflammatory cytokine production. • rCypA activates the NF-κB pathway in acinar cells in vitro. - Abstract: Inflammation triggered by necrotic acinar cells contributes to the pathophysiology of acute pancreatitis (AP), but its precise mechanism remains unclear. Recent studies have shown that Cyclophilin A (CypA) released from necrotic cells is involved in the pathogenesis of several inflammatory diseases. We therefore investigated the role of CypA in experimental AP induced by administration of sodium taurocholate (STC). CypA was markedly upregulated and widely expressed in disrupted acinar cells, infiltrated inflammatory cells, and tubular complexes. In vitro, it was released from damaged acinar cells by cholecystokinin (CCK) induction. rCypA (recombinant CypA) aggravated CCK-induced acinar cell necrosis, promoted nuclear factor (NF)-κB p65 activation, and increased cytokine production. In conclusion, CypA promotes pancreatic damage by upregulating expression of inflammatory cytokines of acinar cells via the NF-κB pathway.