Overexpression of pim-3 and protective role in lipopolysaccharide-stimulated hepatic stellate cells

Pim-3 alleviates lipopolysaccharide-stimulated AR42J pancreatic acinar cell injury via improving the inflammatory microenvironment

Acute pancreatitis (AP) is a common acute abdominal disease characterized by pancreatic aseptic inflammation, with ~20% of patients progressing to severe AP (SAP) with a high mortality rate. The aim of this study was to explore the protective effects of Pim-3 proto-oncogene, serine/threonine kinase (Pim-3) on rat pancreatic acinar AR4-2J cells damaged by lipopolysaccharide (LPS). The recombinant plasmid p-enhanced green fluorescent protein (pEGFP)-N2/Pim-3 was transiently transfected into AR42J cells and the AR42J cells were then treated with 2 µg/ml LPS. Subsequently, the proliferation of AR42J cells was detected using MTT assay. The cell cycle progression and apoptosis rate of the AR42J cells were examined using flow cytometry. AR42J cell migration was assessed using wound healing assays. Additionally, RT-semi quantitative PCR and western blot analyses were used to detect the mRNA and protein expression levels, respectively, of Pim-3, interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, intercellular adhesion molecule (ICAM)-1 and Occludin in AR42J cells. The results revealed that proliferation of AR42J cells was significantly enhanced and cell apoptosis was markedly reduced in the pEGFP-N2/Pim-3 + LPS group. The proportion of AR42J cells in G1 phase in the pEGFP-N2/Pim-3 + LPS group was decreased, whereas the proportion of cells in the G2 and S phases was increased. The wound healing assays demonstrated that AR42J cell migration was significantly increased in the pEGFP-N2/Pim-3 + LPS group. Finally, the expression levels of IL-6, IL-1β, TNF-α and ICAM-1 were significantly decreased in the pEGFP-N2/Pim-3 + LPS group, whereas the expression of Occludin was significantly increased. The present study demonstrated that raised expression levels of Pim-3 can protect AR42J cells from LPS-induced injury by modifying the inflammatory microenvironment, suggesting that Pim-3 may be a potential target for AP or SAP therapy.

Role of mitophagy regulation by ROS in hepatic stellate cells during acute liver failure

Liver sinusoids serve as the first line of defense against extrahepatic stimuli from the intestinal tract. Hepatic stellate cells (HSCs) are pericytes residing in the perisinusoidal space that integrate cytokine-mediated inflammatory responses in the sinusoids and relay these signals to the liver parenchyma. Oxidative stress has been shown to promote inflammation during acute liver failure (ALF). Whether and how oxidative stress is involved in HSC inflammation during ALF remains unclear. Level of systemic oxidative stress is reflected by superoxide dismutase (SOD). Thus, ALF patients were recruited to investigate the correlation between plasma SOD levels and clinical features. Liver tissues were collected from chronic hepatitis patients by biopsy and from ALF patients who had undergone liver transplantation. SOD2 expression and HSCs activation were investigated by immunohistochemistry. Inflammation, mitophagy, and apoptosis were investigated by immunoblot analysis and flow cytometry in HSCs treated with lipopolysaccharide (LPS) and reactive oxygen species (ROS) donors. The plasma SOD level was significantly increased in patients with ALF compared with those with cirrhosis (444.4 ± 23.58 vs. 170.07 ± 3.52 U/ml, P < 0.01) and was positively correlated with the Model for End-Stage Liver Disease-Na score ( R² = 0.4720, P < 0.01). In vivo observations revealed that SOD2 immunostaining was increased in ALF patients and mice models, and in vitro experiments demonstrated that LPS/ROS promoted inflammation via inhibiting mitophagy. Moreover, the regulation of inflammation was apoptosis independent in HSCs. LPS-induced increases in oxidative stress promote inflammation through inhibiting mitophagy in HSCs during the process of ALF, providing a novel strategy for the treatment of patients with ALF. NEW & NOTEWORTHY Here we demonstrate that the serum superoxide dismutase (SOD) level is significantly increased in patients with acute liver failure (ALF), and, correlated with the Model for End-Stage Liver Disease-Na score, SOD level dropped in the remission stage of ALF. We identify that, in liver tissue from ALF patients and mice models, manganese-dependent SOD was overexpressed, and show lipopolysaccharide/H₂O₂ inhibits mitophagy via reactive oxygen species in hepatic stellate cells (HSCs). We show that inhibited mitophagy promotes inflammation in HSCs, whereas mitophagy inducer rescues HSCs from lipopolysaccharide-induced inflammation.

Pim-3 as a potential predictor of chemoradiotherapy resistance in locally advanced rectal cancer patients

Approximately 30% of locally advanced rectal cancer patients might not benefit from chemoradiotherapy; however, the response to neoadjuvant chemoradiotherapy in these cases is difficult to predict. Pim-3 is a member of the provirus integration site for a moloney murine leukemia virus family of proteins that contributes to cell proliferation, survival, and chemotherapy resistance. Therefore, the relationship between Pim-3 expression and response to neoadjuvant chemoradiotherapy in rectal cancer patients is important to evaluate. 175 rectal cancer patients who underwent neoadjuvant treatment enrolled in this study. The relationship between Pim-3 expression on immunohistochemical analysis of rectal cancer tissue, which was obtained before treatment, the response to chemoradiotherapy and survival was investigated. The patients with no Pim-3 expression were more likely to achieve a pathologic complete response to chemoradiotherapy than patients with Pim-3 expression (P = 0.001). Cox multivariate analysis showed that the significant prognostic factors were Pim-3 expression (P = 0.003) and the number of neoadjuvant chemotherapy cycles (P = 0.005) for overall survival. Neoadjuvant chemotherapy cycles (P = 0.007), adjuvant chemotherapy cycles (P = 0.004) and pathology types (P = 0.049) were significant prognostic factors for disease-free survival. Pim-3 is a potential predictive biomarker for the response of rectal cancer to chemoradiotherapy.

Intra-corporeal hand-sewn esophagojejunostomy is a safe and feasible procedure for totally laparoscopic total gastrectomy: short-term outcomes in 100 consecutive patients

BACKGROUND

An optimal method for intracorporeal esophagojejunostomy has not yet been standardized. This study sought to introduce intracorporeal hand-sewn end-to-side esophagojejunostomy after totally laparoscopic total gastrectomy.

METHODS

The author conducted a consecutive series of 100 intracorporeal hand-sewn esophagojejunostomies after totally laparoscopic total gastrectomy for upper third gastric cancer from September 2012 to December 2016.

RESULTS

All patients were successfully operated on without conversion to open- or laparoscope-assisted surgery. The mean reconstruction time was 45 min, and the time until first flatus was 4 days. The time to start a soft diet was 7 days. The length of postoperative hospital stay was 8 days. The overall postoperative morbidity was 8%, including one anastomotic leak, and the mortality was zero. The median follow-up duration was 13 months; no anastomotic strictures were encountered.

CONCLUSIONS

Intracorporeal hand-sewn end-to-side esophagojejunostomy after totally laparoscopic total gastrectomy is a safe and feasible procedure. This method can identify negative margins with intraoperative frozen sections before reconstruction and could be a good option for performing intracorporeal esophagojejunostomy with an advanced endoscopic suture technique.

Pim-3 contributes to radioresistance through regulation of the cell cycle and DNA damage repair in pancreatic cancer cells

Resistance of cancer cells to chemoradiotherapy is a major clinical problem in pancreatic cancer treatment. Therefore, understanding the molecular basis of cellular resistance and identifying novel targets are essential for improving treatment efficacy for pancreatic cancer patients. Previous studies have demonstrated a significant role for Pim-3 in pancreatic cancer survival against gemcitabine-induced genotoxic stress. Here, we observed that radiation treatment enhanced Pim-3 expression in human pancreatic cancer cells in vitro. Stable overexpression of Pim-3 in pancreatic cancer cells significantly protected cells against radiation treatment by attenuating G2/M phase cell cycle arrest and DNA damage response. Silencing of Pim-3 expression significantly elevated the phosphorylation of histone variant H2AX, a marker of DNA double strand breaks, and decreased the activation of ataxia-telangiectasia-mutated (ATM) kinase, along with its downstream targets, eventually enhancing the radiosensitivity of human pancreatic cancer cells in vitro and in vivo. Hence, we demonstrated a novel function for Pim-3 in human pancreatic cancer cell survival against radiation. Targeting Pim-3 may be a promising way to improve treatment efficacy in combination with radiotherapy in human pancreatic cancer.

Expression of Pim-3 in colorectal cancer and its relationship with prognosis

There is increasing evidence suggesting that the establishment of Pim-3 is involved in tumorigenesis. This study aimed to investigate the expression and clinicopathological significance of Pim-3 in colorectal cancer (CRC). Clinical pathology data were collected from 410 CRC patients who received radical resection and were pathologically confirmed at the Sun Yat-Sen University Cancer Center between October 2002 and December 2008. We compared the expression Pim-3 in the primary focus and liver metastasis and investigated the correlations with other clinical-pathological factors. Multivariate analysis showed that perioperative blood transfusion, local invasion, lymph node and liver metastasis, and Pim-3 expression were independent prognostic factors. The expression of Pim-3 in CRC was higher than that in normal tissues. Patients with positive expression had significant decreases in 5-year survival. Pim-3 expression showed a positive correlation with tumor cell differentiation, local infiltration, and lymph node and liver metastasis. In conclusion, Pim-3 might serve as a novel target and prognosis factor for colorectal cancer.