Fluorescence probes evaluated the hydrogen peroxide level in rice roots under cadmium ion stress.

Abiotic stress and oxidative stress are closely related to the health status of plants. Plants will produce oxidative stress under abiotic stress, induce mitochondrial dysfunction, cause programmed cell death, and decrease plant survival rate. It is well known that rice is an essential crop for humans, but its cadmium tolerance is poor. Therefore, it is crucial to determine whether cadmium stress causes oxidative stress in rice in order to guide rice cultivation. Hydrogen peroxide (H2O2), a highly reactive oxygen species (ROS), is one of the most critical signals in corps under oxidative stress. In this work, we adopted a near-infrared (NIR) H2O2 fluorescent probe YFE-1 and a cadmium ion (Cd2+) fluorescent probe SCP to observe the fluctuation of H2O2 in rice roots under Cd2+ co-incubation conditions. Due to the advantages of fast response (within 2 min), a large Stokes shift (181 nm), good selectivity, and a low detection limit (LOD:26.4 nM), YFE-1 achieved the visualization of H2O2 produced by Cd2+ stress in rice roots. This study provides a new idea for assessing the risk of oxidative stress of Cd2+ in rice roots. It is expected to guide the control of Cd2+ in the rice planting industry to improve rice yield.

Schisandrin B Improves the Hypothermic Preservation of Celsior Solution in Human Umbilical Cord Mesenchymal Stem Cells.

BACKGROUND: Human umbilical cord mesenchymal stem cells (hUCMSCs) have emerged as promising therapy for immune and inflammatory diseases. However, how to maintain the activity and unique properties during cold storage and transportation is one of the key factors affecting the therapeutic efficiency of hUCMSCs. Schisandrin B (SchB) has many functions in cell protection as a natural medicine. In this study, we investigated the protective effects of SchB on the hypothermic preservation of hUCMSCs. METHODS: hUCMSCs were isolated from Wharton's jelly. Subsequently, hUCMSCs were exposed to cold storage (4 °C) and 24-h re-warming. After that, cells viability, surface markers, immunomodulatory effects, reactive oxygen species (ROS), mitochondrial integrity, apoptosis-related and antioxidant proteins expression level were evaluated. RESULTS: SchB significantly alleviated the cells injury and maintained unique properties such as differentiation potential, level of surface markers and immunomodulatory effects of hUCMSCs. The protective effects of SchB on hUCMSCs after hypothermic storage seemed associated with its inhibition of apoptosis and the anti-oxidative stress effect mediated by nuclear factor erythroid 2-related factor 2 signaling. CONCLUSION: These results demonstrate SchB could be used as an agent for hypothermic preservation of hUCMSCs.

Nomogram predicts CR-POPF in open central pancreatectomy patients with benign or low-grade malignant pancreatic neoplasms.

Introduction: Central pancreatectomy (CP) is a standard surgical procedure for benign and low-grade malignant pancreatic neoplasms in the body and neck of the pancreas. Higher incidence of clinically relevant postoperative pancreatic fistula (CR-POPF) after CP than after pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) has been reported, but no nomogram for prediction of CR-POPF after open CP has been previously established. Methods: Patients undergoing open CP for benign or low-grade malignant pancreatic neoplasms in the department of Hepatobiliary and Pancreatic (HBP) surgery of Shanghai Changhai Hospital affiliated to Naval Medical University between January 01, 2009 and December 31,2020 were enrolled. Pre-, intra- and post-operative parameters were analyzed retrospectively. Results: A total of 194 patients, including 60 men and 134 women, were enrolled with median age of 52 years (21~85 years). 84 patients (43.3%) were overweight (BMI>23.0 Kg/m2) and 14 (7.2%) were obese (BMI>28.0 Kg/m2). Pathological diagnoses ranged from serous cystic neoplasm (32.5%), solid pseudopapillary neoplasm (22.2%), pancreatic neuroendocrine tumor (20.1%), intraductal papillary mucinous neoplasm (18.0%) to mucinous cystic neoplasm (5.2%). All patients had soft pancreatic texture. Main pancreatic duct diameters were ≤0.3cm for 158 patients (81.4%) and were ≥0.5cm in only 12 patients (6.2%). A stapler (57.7%) or hand-sewn closure (42.3%) were used to close the pancreatic remnant. The pancreatic anastomosis techniques used were duct to mucosa pancreaticojejunostomy (PJ)-interrupted suture (47.4%), duct to mucosa PJ-continuous suture (43.3%), duct to mucosa "HO" half-purse binding PJ (5.2%) and invaginating pancreaticogastrostomy (4.1%). Post-surgical incidences of CR-POPF of 45.9%, surgical site infection of 28.9%, postpancreatectomy hemorrhage of 7.7% and delayed gastric emptying of 2.1% were found. Obesity and pancreatic anastomosis technique were independent risk factors of CR-POPF, with a concordance index of 0.675 and an Area Under the Curve of 0.678. Discussion: This novel nomogram constructed according to obesity and pancreatic anastomosis technique showed moderate predictive performance of CR-POPF after open CP.

Radical antegrade modular pancreatosplenectomy versus standard distal pancreatosplenectomy for pancreatic cancer, a dual-institutional analysis.

BACKGROUND: Radical antegrade modular pancreatosplenectomy (RAMPS) has been adopted by some surgeons in the treatment of left-sided pancreatic cancer (PDAC). Low disease incidence and heterogenous disease biology make robust prospective comparison of RAMPS and standard distal pancreatosplenectomy (DPS) difficult. METHODS: Consecutive cases of chemo-naïve patients undergoing open RAMPS and DPS for PDAC between 2010-2017 at two international high-volume pancreatectomy centers were compared. Cox proportional hazard modeling was utilized for multivariate analysis. RESULTS: We identified 193 DPS and 253 RAMPS during the study period. DPS was associated with higher rates of median estimated blood loss (500 vs. 300 cc, P<0.001), median total harvested lymph nodes (18 vs. 12, P<0.001) and R0 resection (94.3% vs. 88.9%, P=0.013). There were no differences in rates of postoperative pancreatic fistula (16.5% vs. 17.8%, P=1) or postoperative hemorrhage (5.9% vs. 3.6%, P=0.385) (DPS vs. RAMPS). After controlling for significant clinical pathological parameters, RAMPS was associated with non-superior recurrence-free survival (RFS) (HR 0.29; 95% CI, 0.07-1.27, P=0.101) and overall-survival (HR 1.03; 95% CI, 0.71-1.49, P=0.895) compared with DPS. Similar results were observed in node-positive patients. CONCLUSIONS: RAMPS is safe and effective in the treatment of PDAC, but is not associated with an improvement in either RFS or overall-survival over DPS.

TSG101 Silencing Suppresses Hepatocellular Carcinoma Cell Growth by Inducing Cell Cycle Arrest and Autophagic Cell Death.

BACKGROUND: The tumor susceptibility gene 101 (TSG101) was originally identified as a tumor-suppressor gene that mediates many molecular and biological processes, such as ubiquitination, endosomal trafficking, cell survival, and virus budding, but its role in hepatocellular carcinoma (HCC) is currently unknown. MATERIAL AND METHODS: We assessed the expression of TSG101 in HCC and paracancerous tissues using qPCR. Then, we used the TSG101-specific siRNA mix to disrupt the expression of TSG101 to investigate the subsequent effect on human hepatoma-7 (Huh7) cells. Western blot was used to detect the protein expression of TSG101 and other molecules. Cell growth assay was performed using CCK8. Transwell assay was used to investigate the migration and invasion ability of Huh7 cells after transfection with of TSG101 siRNA. Flow cytometry was used to estimate the effect of TSG101 knockdown on cell cycle and apoptosis. Confocal laser scanning microscopy was used to observe the actin filaments change and the formation of autophagy. RESULTS: TSG101 was over-expressed in HCC tissues. TSG101 silence was able to suppress Huh7 cell proliferation, migration, and invasion. Furthermore, silencing of TSG101 could induce cell cycle arrest at G1 phase and inhibit the expression of cyclin A and cyclin D, while up-regulating the expression of CDK2. The mechanism might be induction of autophagic cell death and inactivation of Akt and ERK1/2. CONCLUSIONS: TSG101 plays an important role in the development of HCC and may be a target for molecular therapy.

Downregulation of ASPP2 in pancreatic cancer cells contributes to increased resistance to gemcitabine through autophagy activation.

BACKGROUND: Apoptosis-stimulating of p53 protein 2 (ASPP2) is one of the ASPP family members and it has been reported to be associated with human cancer. However, the role of it in pancreatic cancer is still not clear. METHODS: We analyzed the expression level of ASPP2 in cancer tissue samples with RT-qPCR, Western Blotting assay and immunohistochemistry staining. We studied the biological function of ASPP2 and its mechanism with gene overexpression and gene silencing technologies. We determined the sensitivity of pancreatic cells with differential ASPP2 level to gemcitabine and whether autophagy inhibition affected the gemcitabine resistance, both in vitro and in vivo. RESULTS: Expression of ASPP2 was downregulated in cancerous tissues in comparison with para-cancerous tissues. ASPP2 expression was linked to clinical outcomes in patients and down-regulation of ASPP2 increased cell proliferation, autophagic flux, the activity of AMP Kinase of pancreatic cancer cells and vice versa. Knockdown of ASPP2 results in increased resistance to gemcitabine, which was attributed to the enhanced autophagy. CONCLUSIONS: ASSP2 expression is lower in cancerous tissues and decreased ASPP2 lead to higher cancer cells proliferation and autophagic flux, which contribute to the gemcitabine resistance.

Sox2 function as a negative regulator to control HAMP expression.

BACKGROUND: Hepcidin, encoding by HAMP gene, is the pivotal regulator of iron metabolism, controlling the systemic absorption and transportation of irons from intracellular stores. Abnormal levels of HAMP expression alter plasma iron parameters and lead to iron metabolism disorders. Therefore, it is an important goal to understand the mechanisms controlling HAMP gene expression. RESULTS: Overexpression of Sox2 decrease basal expression of HAMP or induced by IL-6 or BMP-2, whereas, knockdown of Sox2 can increase HAMP expression, furthermore, two potential Sox2-binding sites were identified within the human HAMP promoter. Indeed, luciferase experiments demonstrated that deletion of any Sox2-binding site impaired the negative regulation of Sox2 on HAMP promoter transcriptional activity in basal conditions. ChIP experiments showed that Sox2 could directly bind to these sites. Finally, we verified the role of Sox2 to negatively regulate HAMP expression in human primary hepatocytes. CONCLUSION: We found that Sox2 as a novel factor to bind with HAMP promoter to negatively regulate HAMP expression, which may be further implicated as a therapeutic option for the amelioration of HAMP-overexpression-related diseases, including iron deficiency anemia.

Ulinastatin reduces the resistance of liver cancer cells to epirubicin by inhibiting autophagy.

During chemotherapy, drug resistance caused by autophagy remains a major challenge to successful treatment of cancer patients. The purpose of this study is to show that ulinastatin (UTI), a trypsin inhibitor, could reduce the resistance of liver cancer cells to chemotherapeutic agent epirubicin (EPI). We achieved this conclusion by analyzing the effect of EPI alone or UTI plus EPI on SMMC-7721 and MHCC-LM3 liver cancer cells. We also generated an EPI-resistant liver cancer cell line (MHCC-LM3er cells), and found that UTI could sensitize the LM3er cells to EPI. Autophagy usually functions to protect cancer cells during chemotherapy. Our study showed that UTI inhibited the autophagy induced by EPI in liver cancer cells, which promoted apoptosis, and therefore, reduced the resistance of the cancer cells to EPI. Further studies showed that the UTI-mediated inhibition on autophagy was achieved by inhibiting transcriptional factor nuclear factor-κB (NF-κB) signaling pathway. To verify our results in vivo, we injected MHCC-LM3 liver cancer cells or EPI-resistant LM3er cells into mice, and found that EPI could only effectively inhibit the growth of tumor in MHCC-LM3 cell-injected mice, but not in LM3er cell-injected mice. However, when UTI was also administered, the growth of tumor was inhibited in the MHCC-LM3er cell-injected mice as well. Our results suggest that UTI may be used in combination with anti-cancer drugs, such as EPI, to improve the outcome of cancer therapy.

Sox2 function as a negative regulator to control HAMP expression

BACKGROUND: Hepcidin, encoding by HAMP gene, is the pivotal regulator of iron metabolism, controlling the systemic absorption and transportation of irons from intracellular stores. Abnormal levels of HAMP expression alter plasma iron parameters and lead to iron metabolism disorders. Therefore,itis animportant goal to understand the mechanisms controlling HAMP gene expression. RESULTS: Overexpression of Sox2 decrease basal expression of HAMP or induced by IL-6 or BMP-2, whereas, knockdown of Sox2 can increase HAMP expression, furthermore, two potential Sox2-binding sites were identified within the human HAMP promoter. Indeed, luciferase experiments demonstrated that deletion of any Sox2-binding site impaired the negative regulation of Sox2 on HAMP promoter transcriptional activity in basal conditions. ChIP experiments showed that Sox2 could directly bind to these sites. Finally, we verified the role of Sox2 to negatively regulate HAMP expression in human primary hepatocytes. CONCLUSION: We found that Sox2 as a novel factor to bind with HAMP promoter to negatively regulate HAMP expression, which may be further implicated as a therapeutic option for the amelioration of HAMP-overexpression-related diseases, including iron deficiency anemia.

Human umbilical cord blood-derived mesenchymal stem cells producing IL15 eradicate established pancreatic tumor in syngeneic mice.

Mesenchymal stem cells (MSC) represent a new tool for delivery of therapeutic agents to cancer sites because of their strong tropism toward tumors. IL15 has demonstrated a potent antitumor activity in various animal models as well as clinical trials. However, because of its short half-life, effective therapeutic effects usually require a high dose, which often results in undesired side effects; thus, new strategies for overcoming this disadvantage are needed. In this study, human MSCs were isolated from umbilical cord blood as delivery vehicles and transduced with lentivirus vector expressing murine IL15 (MSC-IL15). In vitro assays of lymphocyte activation and proliferation demonstrated that IL15 produced by MSCs was biofunctional. In syngeneic mice bearing Pan02 pancreatic tumors, systemic administration of MSC-IL15 significantly inhibited tumor growth and prolonged the survival of tumor-bearing mice, which were associated with tumor cell apoptosis, and natural killer (NK)- and T-cell accumulation. Furthermore, we confirmed that MSC-IL15 could migrate toward tumor and secreted IL15 in tumor-specific sites. Depletion of NK and CD8(+) T cells abolished the antitumor activity of MSC-IL15, suggesting that NK and CD8(+) T cells play a key role for MSC-IL15-mediated effect. Interestingly, cured mice after MSC-IL15 treatment were resistant to Pan02 pancreatic tumor rechallenge, and adoptive transfer of lymphocytes from cured mice also could cause rejection of Pan02 tumor inoculation in naïve mice, indicating that MSC-IL15 induced tumor-specific T-cell immune memory response. Overall, these data support that MSCs producing IL15 might represent an innovative strategy for therapy of pancreatic tumor.

The UPF1 RNA surveillance gene is commonly mutated in pancreatic adenosquamous carcinoma.

Pancreatic adenosquamous carcinoma (ASC) is an enigmatic and aggressive tumor that has a worse prognosis and higher metastatic potential than its adenocarcinoma counterpart. Here we report that ASC tumors frequently harbor somatically acquired mutations in the UPF1 gene, which encodes the core component of the nonsense-mediated RNA decay (NMD) pathway. These tumor-specific mutations alter UPF1 RNA splicing and perturb NMD, leading to upregulated levels of NMD substrate mRNAs. UPF1 mutations are, to our knowledge, the first known unique molecular signatures of pancreatic ASC.

Growth inhibition and apoptosis induced by 6-fluoro-3-formylchromone in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most lethal and prevalent cancers in human population. The 6-fluoro-3-formylchromone (FCC) has been shown to have anti-tumor activity against various tumor cells. However, the effects of FCC on HCC cell lines have not yet been reported. This study aims to research the effects of FCC on HCC and advance the understanding of the molecular mechanism. METHODS: HCC cell line SMMC-7721 was treated with FCC at various concentrations (0, 2, 5, 10, and 20 µg/ml) for 24, 48 and 72 h, respectively. The proliferations of SMMC-7721 cells were measured by MTT assays. After cultured 24 hours, cell cycle distribution and apoptosis were determined by flow cytometry. However, the expression levels of PCNA, Bax and Bcl-2 were measured by western blotting after 48 hours. RESULTS: FCC displayed a dose- and time-dependent inhibition of the SMMC-7721 cell proliferations in vitro. It also induced apoptosis with 45.4% and caused cell accumulation in G0/G1 phase with 21.5%. PCNA and Bcl-2 expression was significantly suppressed by FCC in a dose-dependent manner (P < 0.05), while Bax expression was increased. CONCLUSIONS: FCC could significantly inhibit HCC cell growth in vitro through cell cycle arrest and inducing apoptosis by suppressing PCNA expression and modulating the Bax/Bcl-2 ratio.

Characteristics of white coat hypertension in Chinese Han patients with type 2 diabetes mellitus.

OBJECTIVES: This study documented the prevalence and clinical features of white coat hypertension (WCH) among Chinese Han patients with type 2 diabetes mellitus (T2DM). METHODS: Clinic and ambulatory blood pressure (BP) measurements were compared in 856 patients with T2DM to determine the frequency of WCH (WCH was defined as clinical blood pressure ≥140/90 mmHg and daytime blood pressure <135/85 mmHg and/or 24-h ambulatory BP (ABP) mean value of <130/80 mmHg on ambulatory BP monitoring (ABPM). Weight, waist circumference (WC), body mass index (BMI), waist to height ratio (WHtR), fasting blood glucose, glycosylated hemoglobin level and circadian BP patterns were also measured to find clinical features predictive of WCH in T2DM. RESULTS: The prevalence of WCH was 7.36% (63/856) in the overall population, 6.13% (29/473) in male and 8.88% (34/383) in female (p < 0.05). WCH accounted for 14.03% (63/449) of diagnosed hypertension. Age, course of T2DM, male WC were independent protective factors, whereas female sex, smoking and alcohol consumption were independent risk factors for WCH in T2DM. Non-dippers and reverse dippers made up larger proportion of the WCH group (p < 0.01). CONCLUSION: WCH is relatively common among T2DM patients, it is a unique condition distinct from essential hypertension (EH), and WCH patients also exhibit significant differences in clinical parameters.

Prevalence and distinguishing features of masked hypertension in type 2 diabetic patients.

OBJECTIVE: The prevalence and clinical features of masked hypertension (MH) in type 2 diabetes mellitus patients (T(2)DM) were investigated to define clinical indices which may aid diagnosis and treatment. METHODS: Clinical blood pressure (CBP) and ambulatory blood pressure (ABP) were measured in 856 T(2)DM patients to differentiate normotensive (NT), essential hypertensive (EH), and MH. Waist circumference (WC), abdominal circumference (AC), body mass index (BMI), waist to height ratio (WHtR), fasting blood glucose (FBG), and glycated hemoglobin levels were measured and compared between BP groups. RESULTS: In total, 359 patients had normal CBP, of which 13.37% were diagnosed with MH based on established criteria. Males had significantly higher rates of MH (15.30%) than females (11.36%) (P=0.036). The MH detection rate increased with age and T(2)DM duration. There were no significant differences in BMI, WC or WHtR between total MH and EH groups. MH females, however, had lower BMIs than female EH females (P=0.023). Smoking, alcohol, and familial EH history were lower in MH than EH patients (smoking, P=0.029; alcohol ,P=0.001; and EH history, P=0.000), while BMI (male, P=0.037, female, P=0.015), WC (male, P=0.012, female, P=0.021), WHtR (P=0.011), smoking (P=0.016), and alcohol consumption (P=0.000) were higher in MH than NT patients. BMI, WHtR, 6-15 year disease course of diabetes, smoking and alcoholism were independent risk factors of T(2)DM complicated with MH. The dipper BP circadian pattern was significantly lower in MH than NT patients (P=0.001). The non-dipper pattern was lower in MH than EH (P=0.018) but higher than in NT (P=0.000). CONCLUSIONS: A significant fraction of T(2)DM patients were diagnosed with MH. Clinical presentation also contrasted sharply from EH, MH is a specific blood pressure status that may severely damage target organs in T(2)DM.

Distal pancreatectomy with en bloc celiac axis resection for the treatment of locally advanced pancreatic body and tail cancer.

BACKGROUND/AIMS: Pancreatic body and tail carcinoma (PBTC) is an aggressive disease with a low resectability rate. Celiac axis infiltration usually contraindicates resection. Extended distal pancreatectomy with combined en bloc celiac axis resection (DP-CAR, also named Appleby operation) was described as a new concept for the curative treatment of these tumors. The aim of this study was to analyze the results of DP-CAR in PBTC. METHODOLOGY: Analyze by summarizing the 24 cases of PBTC during October 2005 to August 2010 in the pancreatic surgery of our hospital and analyzing the clinical manifestations, surgical processing, pathological effects and survival rate of the patients. RESULTS: The postoperative mortality rate was 0%, despite a high morbidity rate (54%). Preoperative intractable abdominal and/or back pain in all the patients was completely alleviated immediately after surgery. During the follow-up survey among all the patients of 2 to 37 months (with an average follow-up survey of 12.67 months), no patient was still alive, with the median survival of 9.25 months. Estimated overall 1- and 3-year survival rates were 46% and 4%, respectively. CONCLUSIONS: DP-CAR offers a high resectability rate without increasing the mortality rate given skilled surgical technique.

Analysis of tumor-induced lymphangiogenesis and lymphatic vessel invasion of pancreatic carcinoma in the peripheral nerve plexus.

Cancer cells can metastasize throughout the body by various mechanisms, including the lymphatic system, resulting in tumor-induced lymphangiogenesis that can profoundly affect patient survival. The aim of the present study was to examine the role of lymphangiogenesis in the metastasis of pancreatic cancer to the peripheral nerve plexus. Immunohistochemistry was performed to analyze specimens obtained from 70 ductal adenocarcinoma patients. The markers used included lymphangiogenic factor vascular endothelial growth factor (VEGF)-C, the lymphatic-specific marker D2-40, and cytokeratin 19, an independent prognostic factor for pancreatic tumors. The relationship between survival rate and invasion of both the lymphatic vessels and peripancreatic nerve plexus (PNP) was evaluated, with clearly elevated lymphatic vessel density (LVD) in tissues adjacent to the cancer tissues. In fact, LVD levels were higher in adjacent tissues than in localized cancer tissues, and lymphatic vessel invasion into tissues adjacent to the tumor was significantly correlated with both PNP invasion (P = 0.005) and lymph node metastasis (P = 0.010). Correspondingly, LVD in tissues adjacent to the tumor was correlated with both invasion of lymphatic vessels surrounding the tumor (P = 0.024) and VEGF-C expression (P = 0.031); in addition, VEGF-C expression was correlated with invasion of lymphatic vessels around the tumor (P = 0.004). Survival rates were significantly lower in patients in whom there was peritumor lymphatic vessel invasion (P < 0.001), extrapancreatic nerve plexus invasion (P = 0.001), and/or lymph node metastasis (P < 0.001). Based on these results, lymphatic invasion associated with adjacent tumor growth likely contributes to the development of metastatic tumors that invade the PNP.

Cytoplasmic p21 induced by p65 prevents doxorubicin-induced cell death in pancreatic carcinoma cell line.

BACKGROUND: Studies have shown the existence of p21 induction in a p53-dependent and -independent pathway. Our previous study indicates that DOX-induced p65 is able to bind the p21 promoter to activate its transactivation in the cells. METHODS: Over-expression and knock-down experiments were performed in Human Pancreatic Carcinoma (PANC1) cells. Cell cycle and cell death related proteins were assessed by Western Blotting. Cytotoxicity assay was checked by CCK-8 kit. Cell growth was analyzed by flow cytometers. RESULTS: Here we showed that over-expression of p65 decreased the cytotoxic effect of DOX on PANC1 cells, correlating with increased induction of cytoplasmic p21. We observed that pro-caspase-3 physically associated with cytoplasmic p21, which may be contribution to prevent p21 translocation into the nucleus. Our data also suggested that no clear elevation of nuclear p21 by p65 provides a survival advantage by progression cell cycle after treatment of DOX. Likewise, down-regulation of p65 expression enhanced the cytotoxic effect of DOX, due to a significant decrease of mRNA levels of anti-apoptotic genes, such as the cellular inhibitor of apoptosis-1 (c-IAP1), and the long isoform of B cell leukemia/lymphoma-2 (Bcl-2), leading to efficient induction of caspase-3 cleavage in the cells. More, we present evidence that over-expression of p53 or p53/p65 in the PANC1 cells were more sensitive to DOX treatment, correlated with activation of caspase-3 and clear elevation of nuclear p21 level. Our previous data suggested that expression of p21 increases Gefitinib-induced cell death by blocking the cell cycle at the G1 and G2 phases. The present findings here reinforced this idea by showing p21's ability of potentiality of DOX-induced cell death correlated with its inhibition of cell cycle progression after over-expression of p53 or p53/p65. CONCLUSION: Our data suggested p65 could increase p53-mediated cell death in response to DOX in PANC1 cells. Thus, it is worth noting that in p53 null or defective tumors, targeting in down-regulation of p65 may well be useful, leading to the potentiality of chemotherapeutic drugs.

Reduced levels of p15INK4b, p16INK4a, p21cip1 and p27kip1 in pancreatic carcinoma.

Pancreatic carcinoma is one of the leading causes of cancer mortality worldwide, although the molecular mechanisms of this disease are poorly understood. The aim of this study was to examine the expression of cyclin-dependent kinase inhibitors (CDKIs) and the epigenetic modifications in the promoters of these genes. We also evaluated the correlation between the methylation status of CDKI genes and smoking habit in clinical pancreatic carcinoma specimens. Western blotting and real-time PCR were performed to assess CDKI expression. Methylation-specific PCR was carried out to examine the methylation status of the promoters of CDKI genes. In this study, we revealed that reduced levels of the CDKI proteins, p15INK4b, p16INK4a, p21cip1 and p27kip1, are a prominent feature of pancreatic carcinoma patients. The DNA hypermethylation of the promoter was observed in 40% (2 of 5) of the p15INK4b genes, 60% (3 of 5) of the p16INK4a genes and 60% of the p21cip1 genes, which markedly correlated with their decreased mRNA expression. No hypermethylation was detected in the p27kip1 gene promoter in 5 pancreatic carcinoma patients with markedly decreased expression of p27kip1 mRNA, suggesting an alternative mechanism of p27kip in these patients. In this study, patients with a smoking habit displayed methylation of 2 CDKI genes in their pancreatic carcinoma specimens. We concluded that epigenetic modification via hypermethylation represents a critical mechanism for the inactivation of CDKI genes in pancreatic carcinoma.

Diabetes mellitus and increased risk of cholangiocarcinoma: a meta-analysis.

Diabetes mellitus (DM) has been reported to be associated with an increased risk of several types of cancers. However, its relationship with cholangiocarcinoma (CC), which includes intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC), remains unclear. We conducted a meta-analysis to assess the association between diabetes and the risk of CC (including ICC and ECC). We identified studies by a literature search of Medline (from 1 January 1966) and Embase (from 1 January 1974), through 30 November 2010, and by searching the reference lists of pertinent articles. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were calculated with a random-effects model. A total of 15 articles (10 case-control and five cohort studies) were included in this study. The number of reports on DM and risk of specific cancer were as follows: CC (n=5), ECC (n=9), and ICC (n=9). Compared with those without diabetes, individuals with diabetes had an increased risk of CC (summary RRs, 1.60; 95% CI, 1.38-1.87; P=0.992 for heterogeneity), ECC (summary RRs, 1.63; 95% CIs, 1.29-2.05; P=0.005 for heterogeneity), and ICC (summary RRs, 1.97; 95% CIs, 1.57-2.46; P=0.025 for heterogeneity). The funnel plot revealed no evidence for publication bias concerning diabetes and the risk of CC (including ICC and ECC). These findings strongly support the positive link between DM and the increased risk of CC (including ICC and ECC).

MicroRNA 421 suppresses DPC4/Smad4 in pancreatic cancer.

MicroRNAs (miRNAs) have emerged as important regulators in the development of pancreatic cancer and may be a valuable therapeutic application. DPC4/Smad4 is a critical tumor suppressor involved in the progression of pancreatic cancer, but few studies have been conducted to determine its relationship with miRNAs. In this study, we identify miR-421 as a potential regulator of DPC4/Smad4. We find that in human clinical specimens of pancreatic cancer miR-421 is aberrantly upregulated while DPC4/Smad4 is strongly repressed, and their levels of expression are inversely correlated. Moreover, ectopic expression of miR-421 significantly decreases DPC4/Smad4 protein level in pancreatic cancer cell lines and simultaneously promotes cell proliferation and colony formation in vitro. Our findings identify miR-421 as a potent regulator of DPC4/Smad4, which may provide a novel therapeutic strategy for treatment of DPC4/Smad4-driven pancreatic cancer.