The mevalonate coordinates energy input and cell proliferation.

The mevalonate pathway is known for the synthesis of cholesterol, but recent studies have reported that it also controls Hippo signaling, which is critical for the regulation of organ size and tumorigenesis. Here, we discover that the suppression of the mevalonate pathway inhibits the growth and proliferation of colon cancer cell lines. The results of transcriptomic and proteomic assays suggested that the mevalonate pathway controls multiple signaling pathways relevant to cell proliferation, and the results were further confirmed using western blot, PCR, and immunofluorescence assays. As cell proliferation is an energy-consuming process, we postulate that the mevalonate pathway may also control nutrient uptake to coordinate the processes of energy supply and cell proliferation. Here, we found that lovastatin, a mevalonate pathway inhibitor, suppresses glucose and amino acid uptake and lactate acid production. More importantly, mevalonic acid itself is sufficient to promote glucose uptake by colon cancer cells. In addition, we found that colon cancer tissues displayed a higher expression of mevalonate pathway enzymes, which may promote cell growth and stimulate energy uptake. Together, our findings establish the mevalonate pathway as a critical regulator in coordinating energy input and cell proliferation.

Altered Biological Properties in Dp71 Over-Expressing HBE Cells.

BACKGROUND/AIMS: In order to further characterize the biological traits of Dp71, HBE over expressing two most abundantly expressed Dp71 spliced isoforms, Dp71d and Dp71f, were established and their biological traits were explored. METHODS: The proliferation, migration and invasion capabilities of HBE-Dp71d and HBE-Dp71f cells were evaluated by MTT, colony formation, transwell and scratch assay. Cell cycle and apoptosis induced by H2O2 were measured by flow cytometer. Co-IP was performed to prove the interaction between lamin B1, FAK and Dp71. Western blot was performed to detect lamin B1, FAK, ERK and Cyclin D expression in HBE-Dp71d and HBE-Dp71f cells. RESULTS: HBE-Dp71d and HBE-Dp71f cells proliferated faster than their mock and blank controls; shortened their G0/G1 phase; enhanced their invasion and migration capabilities; reduced their apoptosis induced by H2O2. Co-IP proved Dp71 directly interacting with focal adhesion kinase (FAK) and lamin B1 in HBE cells. Increased lamin B1, FAK mRNA and protein expression, over activation of integrin/focal adhesion kinase/extracellular signal-regulated kinase (ERK)/cyclin D pathway were observed in HBE-Dp71d and HBE-Dp71f cells. CONCLUSIONS: Via increasing FAK in the cytoplasmic FAK-Dp71 , lamin B1 of nucleus laminB1-Dp71 complex, HBE-Dp71d and HBE-Dp71f cells alter their proliferation, migration, invasion, cell cycle and apoptosis rate induced by H2O2.

Chemotherapy-induced neutropenia and the prognosis of colorectal cancer: a meta-analysis of cohort studies.

INTRODUCTION: Recently, there has been a controversial discussion about the prognostic value of chemotherapy-induced neutropenia (CIN) in colorectal cancer patients. Thus, a meta-analysis was conducted to determine the relationship between CIN and the prognosis of colorectal cancer patients. METHODS: We searched the PubMed, EMBASE, and Cochrane library databases to identify studies evaluating the association between CIN and colorectal cancer prognosis. Pooled random/fixed effect models were used to calculate pooled hazard ratios (HRs) and 95% confidence intervals (CIs) to assess the association. RESULTS: Eight studies were selected for the meta-analysis, for a total of 2,745 patients. There was significant improved survival among colorectal cancer patients with CIN (HR = 0.62, 95% CI = 0.47-0.76). However, significant heterogeneity was found (p = 0.000, Ι2 = 75.0%). Through subgroup analysis, we could greatly eliminate the heterogeneity and found that neutropenia was associated with better survival in stage IV colorectal cancer patients, no matter the HR calculated by overall survival (OS) or progression-free survival (PFS). Meanwhile, the prognostic value of neutropenia in stage II/III colorectal cancer can be found when the HR is calculated by disease-free survival (DFS). Additionally, we observed significant differences after stratification according to various tumor stages, endpoints, and the use of G-CSF. CONCLUSIONS: Our results which, based on a cohort study, indicate that CIN is associated with improved survival in patients with colorectal cancer. However, further randomized controlled trials are warranted.

EphA2 affects the sensitivity of oxaliplatin by inducing EMT in oxaliplatin-resistant gastric cancer cells.

Erythropoietin-producing hepatocellular receptor A2 (EphA2) is upregulated in gastric cancer tissues and cells, which is accompanied by epithelial-mesenchymal transition (EMT). The current study was designed to establish the oxaliplatin-resistant human gastric cancer cell line SGC-7901/L-OHP, to determine if EMT in these cells could be reversed, and to determine if the susceptibility of these cells to oxaliplatin was affected by silencing EphA2 expression. We found that EphA2 expression levels were upregulated in gastric cancer and associated with chemotherapy sensitivity. EphA2 and the EMT molecular markers N-cadherin and Snail were upregulated in SGC-7901/L-OHP cells, while silencing of EphA2 using small interfering RNA had the opposite effect. Moreover, silencing of EphA2 inhibited cell migration and invasion, and significantly enhanced the sensitivity of oxaliplatin-resistant gastric cancer cells to oxaliplatin. These observations demonstrate that EphA2 affects the sensitivity to oxaliplatin by inducing EMT in oxaliplatin-resistant gastric cancer cells.

[Expression of LXR-ß in human gastric cancer tissue and the effect of GW3965 on the proliferation of gastric cancer cell line SGC-7901].

OBJECTIVE: To examine the expression of liver X receptor-ß (LXR-ß) in human gastric cancer tissue, and to explore the effect of GW3965, an agonist of LXRs, on proliferation of gastric cancer cell line SGC-7901.
 METHODS: The immunohistochemical assay was used to detect the expression of LXR-ß, activating transcription factor 4 (ATF4) in gastric cancer tissues and the corresponding pericarcinoma tissues in 114 patients. Real-time quantitative PCR and Western blot were used to determine mRNA and protein levels of ATF4 and ATP-binding cassette 1 (ABCA1), one of the downstream target genes of LXRs, in SGC-7901 cells with or without GW3965 treatment. Cell counting kit-8 (CCK-8) assay was performed to detect cell proliferation. The expression of ATF4 was silenced by short hairpin RNA (shRNA).
 RESULTS: The expressions of LXR-ß and ATF-4 were obviously down-regulated in the gastric cancer tissues than that in the corresponding pericarcinoma tissues (both P<0.05). Compared with the control cells, GW3965 treatment inhibited proliferation of SGC-7901 cells and up-regulated ATF4 and ABCA1 expressions (both P<0.05). Knockdown of ATF4 can reverse the antiproliferative effect of GW3965 on SGC-7901 cells.
 CONCLUSION: The expression of LXR-ß is decreased in human gastric cancer tissues, and activation of LXRs by GW3965 could inhibit the proliferation of SGC-7901 cells via ATF4.

Knocking down Dp71 expression in A549 cells reduces its malignancy in vivo and in vitro.

Dp71 is one of the most ubiquitously expressed isoforms of dystrophin, the pathological genes of DMD. In order to find whether the alteration of Dp71 can affect the phenotypes of cell other than PC12, an A549 cell line with stably transfected Dp71 siRNA plasmids was set up and named A549-Dp71AS cell. It is demonstrated for the first time that the A549-Dp71AS cell line displayed decreased invasion capabilities, reduced migration ability, decreased proliferation rate, and lessened clonogenic formation. Cisplatin-induced apoptosis was also increased in A549-Dp71AS cell line via enhancing the Caspase 3, Caspase 8, and Caspase 9 activities. Knocking down Dp71 expression can significantly inhibit the A549 xenograft tumor growth in nude mice. The A549-Dp71AS cells and xenograft tumor tissues displayed reduced lamin B1, Bcl-2, and MMP2 protein expression, which accounts for the reduced malignancy of A549-Dp71AS cells in vivo and in vitro.

Metastatic squamous cell carcinoma from hand skin causing small bowel obstruction: an unusual case presentation.

The small bowel rarely suffers from metastatic tumors from outside the abdomen. Small bowel obstructions caused by the metastatic spread of squamous cell carcinoma (SCC) of the hand to the intestines are even rarer. A 71-year-old man with intermittent abdominal distension and pain for 4 months was diagnosed with partial bowel obstruction. The patient underwent a video capsule endoscopic examination; however, the patient was unable to pass the capsule, which worsened the abdominal distension. He was transferred to our department for acute intestinal obstruction, and an emergency exploratory laparotomy was performed. Intraoperatively, a tumoral stricture of the intestine at a distance of 150 cm from the ileo-cecum and dilation of the proximal bowel was found. The involved segment was resected, and ileo-ileal anastomosis was performed. The pathological sections confirmed the lesion to be a moderately differentiated SCC with whole bowel layer infiltration. Immunohistochemical staining showed positive expression of cytokeratin 5/6 and p63. The patient had an uneventful recovery. However, 6 months later, he was hospitalized again with intestinal obstruction. Reoperation was performed and revealed multiple metastases in the small bowel. He died 4 months later. In this unusual case, metastasizing SCC of the hand skin led to intestinal obstruction and poor prognosis. Therefore, follow-up procedures regarding intestinal spread should be performed in patients with SCC who present with abdominal symptoms.

[Construction and evaluation of human Dp71 shRNA vector].

OBJECTIVE: To construct effective short hairpin RNA (shRNA) recombinant plasmids targeting human Dystrophin Dp71 gene, and evaluate their interference efficiency. METHODS: Three pairs of siRNA sequences targeting human Dp71 gene and one pair of control siRNA sequence were designed, synthesized, and then inserted into the pRNAT-U6.1/Neo vector. The shRNA recombinant vectors were evaluated by enzyme digestion and sequencing. Dp71-shRNA and control shRNA plasmids were transfected into human normal gastric epithelial cells (GES-1) and human bronchial epithelium (HBE). Western blot was used to evaluate its interfering efficiency. RESULTS: Restriction enzyme digestion and sequencing showed that the Dp71-shRNA vectors were successfully constructed. Western blot displayed that Dp71 protein expression was reduced to a significant degree after transfection with the 3 Dp71-shRNA plasmids, and Dp71-shRNA2 plasmid inhibit the Dp71 expression most efficiently. CONCLUSION: Dp71-shRNA vectors have been successfully constructed. The 3 Dp71-shRNA plasmids can inhibit Dp71 expression in GES-1 and HBEC, with Dp71-shRNA2 plasmid displaying the highest inhibition efficiency.