The efficacy and safety of snare traction-assisted endoscopic submucosal dissection for circumferential superficial esophageal cancer.

OBJECTIVE: This study aims to investigate the efficacy and safety of snare traction-assisted endoscopic submucosal dissection (ESD) for the management of circumferential superficial esophageal cancer. METHODS: A total of 68 patients who underwent ESD for circumferential superficial esophageal cancer were included in this study. All the patients were divided into two groups based on whether the snare traction was used or not; the snare traction group (S-ESD, group n = 35) and the control group (C-ESD, group n = 33). RESULTS: There was no significant difference in the size of the resected area between the groups [21.98 (18.30, 27.00) cm2 vs 24.00 (15.28, 30.72) cm2, P = 0.976]. The snare traction group had a shorter dissection time [92.00 (74.00, 121.00) min vs 110.00 (92.50, 137.00) min, P = 0.017] and a faster resection speed [0.28 ± 0.13 cm2/min vs 0.22 ± 0.11cm2/min, P = 0.040] compared to the control group. There were no statistically significant differences between the two groups in terms of hospital stay, cost, en bloc resection rate, R0 resection rate, curative resection rate, bleeding rate, perforation rate, stricture rate, and recurrence rate (P > 0.05). CONCLUSION: Snare traction-assisted ESD is a safe and efficient approach for the treatment of circumferential superficial esophageal cancer. Its advantages includes shorter procedure so the anesthesia requirement, clear operative filed view, improved mucosal dissection efficiency, simple, and easily accessible equipment.

A systematic analysis of the resistance and sensitivity of HER2YVMA receptor tyrosine kinase mutant to tyrosine kinase inhibitors in HER2-positive lung cancer.

Human epidermal growth factor receptor 2 (HER2) has become a well-established target for the treatment of HER2-positive lung cancer. However, a frequently observed in-frame mutation that inserts amino acid quadruplex Tyr776-Val777-Met778-Ala779 at G776 (G776(YVMA)) in HER2 kinase domain can cause drug resistance and sensitivity, largely limiting the application of reversible tyrosine kinase inhibitors in lung cancer therapy. A systematic investigation of the intermolecular interactions between the HER2(YVMA) mutant and clinical small-molecule inhibitors would help to establish a complete picture of drug response to HER2 G776(YVMA) insertion in lung cancer, and to design new tyrosine kinase inhibitors with high potency and selectivity to target the lung cancer-related HER2(YVMA) mutant. Here, we combined homology modeling, ligand grafting, structure minimization, molecular simulation and binding affinity analysis to profile a number of tyrosine kinase inhibitors against the G776(YVMA) insertion in HER2. It is found that the insertion is far away from HER2 active pocket and thus cannot contact inhibitor ligand directly. However, the insertion is expected to induce marked allosteric effect on some regions around the pocket, including A-loop and hinges connecting between the N- and C-lobes of HER2 kinase domain, which may exert indirect influence to inhibitor binding. Most investigated inhibitors exhibit weak binding strength to both wild-type and mutant HER2, which can be attributed to steric hindrance that impairs ligand compatibility with HER2 active pocket. However, the cognate inhibitor lapatinib and the non-cognate inhibitor bosutinib were predicted to have low affinity for wild-type HER2 but high affinity for HER2(YVMA) mutant, which was confirmed by subsequent kinase assay experiments; the inhibitory potencies of bosutinib against wild-type and mutant HER2 were determined to be IC(50) > 1000 and =27 nM, respectively, suggesting that the bosutinib might be exploited as a selective inhibitor for mutant over wild-type HER2. Structural examination revealed that formation of additional non-bonded interactions such as hydrogen bonds and hydrophobic contacts with HER2 A-loop region due to G776(YVMA) insertion is the primary factor to improve bosutinib affinity upon the mutation.

TGF-ß-driven LIF expression influences neutrophil extracellular traps (NETs) and contributes to peritoneal metastasis in gastric cancer.

Gastric cancer (GC), notorious for its poor prognosis, often advances to peritoneal dissemination, a crucial determinant of detrimental outcomes. This study intricately explores the role of the TGFß-Smad-LIF axis within the tumor microenvironment in propagating peritoneal metastasis, with a specific emphasis on its molecular mechanism in instigating Neutrophil Extracellular Traps (NETs) formation and encouraging GC cellular functions. Through a blend of bioinformatics analyses, utilizing TCGA and GEO databases, and meticulous in vivo and in vitro experiments, LIF was identified as pivotally associated with GC metastasis, notably, enhancing the NETs formation through neutrophil stimulation. Mechanistically, TGF-ß was substantiated to elevate LIF expression via the activation of the Smad2/3 complex, culminating in NETs formation and consequently, propelling peritoneal metastasis of GC. This revelation uncovers a novel potential therapeutic target, promising a new avenue in managing GC and mitigating its metastatic propensities.

Efficacy and safety of anlotinib plus anti-PD-1 agents in patients with refractory advanced biliary tract cancers.

BACKGROUND: Anlotinib has demonstrated promising anti-tumor efficacy in various solid tumors. Additionally, there is evidence suggesting that immune therapy can enhance the systemic responses of anlotinib. This study aimed to assess the effectiveness and safety of combining anlotinib with PD-1 inhibitors compared to fluoropyrimidine-based chemotherapy as a second-line treatment option for advanced biliary tract cancers (BTCs). METHODS: A total of 242 patients with BTCs were screened at the First Affiliated Hospital of Zhengzhou University from October 2015 to October 2022. Among them, 78 patients who received either anlotinib plus PD-1 inhibitors (AP) or fluoropyrimidine-based chemotherapy (FB) as second-line treatment were included in the study. The primary endpoint was progression-free survival (PFS), and the secondary endpoints included objective response rate (ORR), disease control rate (DCR), overall survival (OS), safety, and predictive tumor biomarkers. RESULTS: Among the 78 patients with BTCs, 39 patients received AP, while 39 patients were administered FB. The ORR in the AP group was 20.5%, compared to 5.1% in the FB group. The DCR was 87.2% in the AP group and 66.7% in the FB group. The AP group demonstrated significantly better ORR and DCR compared to the FB group (p = 0.042, p = 0.032). The median PFS and OS in the AP group were 7.9 months (95% CI: 4.35-11.45) and 13.9 months (95% CI: 5.39-22.41), respectively. In the FB group, the median PFS and OS were 4.1 months (95% CI: 3.17-5.03) and 13.2 months (95% CI: 8.72-17.68), respectively. The AP group exhibited significantly better median PFS than the FB group (p = 0.027). In the subgroup analysis, patients without liver metastasis had a much longer PFS in the AP group compared to the FB group (14.3 vs. 5.5 months, p = 0.016). Similarly, patients with CEA ≤ 5 µg/L also demonstrated a longer PFS in the AP group compared to the FB group (8.7 vs. 3.9 months, p = 0.008). CONCLUSIONS: The combination of anlotinib and PD-1 inhibitors demonstrated a promising clinical effect compared to fluoropyrimidine-based chemotherapy in the second-line treatment of refractory advanced BTCs. Liver metastases and CEA levels may serve as predictive factors for identifying patients who may benefit from AP therapy.

Endoscopic resection of extra-luminal gastric gastrointestinal stromal tumors using a snare assisted external traction technique (with video).

OBJECTIVE: The primary purpose of the study was to explore the clinical efficacy of the novel snare assisted endoscopic resection of extraluminal growing gastric gastrointestinal stromal tumors (gastric GISTs) using external traction, and the secondary purpose was to compare the novel snare assisted endoscopic resection of extraluminal GISTs with the standard laparoscopic procedure. METHODS: We retrospectively analyzed the patients who underwent novel external traction assisted endoscopic resection or laparoscopic resection for their extraluminal gastric GIST ≤5 cm in diameter. RESULTS: A total of 111 patients (27 in the endoscopic group and 84 in the laparoscopic group) were included in this study. There was no significant difference in tumor diameter and complication rate between the two groups. The overall procedure time was slightly higher in the endoscopic group compared to the laparoscopic group (P = 0.034). However, postoperative hospitalization time (P < 0.001) and postoperative fasting time (P = 0.005) were shorter in the endoscopic group compared to the laparoscopic group. CONCLUSION: Snare external traction-assisted endoscopic resection of extraluminal growing gastric GISTs is safe and effective, and it provides a new adjunctive method for endoscopic resection of GIST.

Downregulation of BTG3 in non-small cell lung cancer.

BTG3 is identified as a tumor suppressor gene in some malignancies. Btg3-deficient mice display a higher incidence of lung cancer. These results suggest that BTG3 plays an important role in lung tumorigenesis, although the underlying mechanisms are unknown. The BTG3 expression was detected using immunohistochemical staining and our results showed that the expression of BTG3 was reduced in lung cancer compared to benign lung tissues. We identified two BTG3 isoforms present in lung cancer: Full-length BTG3 and BTG3b lacking the 44 amino acids. BTG3 was predominantly expressed in benign lung tissues, whereas its expression was generally undetectable in lung cancer and cancer cell lines. Functional analysis revealed that BTG3 but not BTG3b inhibited lung cancer growth. Our results disclosed an important role of BTG3 in lung tumorigenesis.

Efficacy analysis of endoscopic treatment of giant gastric gastrointestinal stromal tumors (≥5 cm).

OBJECTIVE: To investigate the safety, feasibility and prognosis of endoscopic treatment of giant (≥5 cm) gastric gastrointestinal stromal tumors (gastric GISTs). METHODS: Data from patients who underwent surgical resection of nonmetastatic gastric GISTs in our hospital from January 2016 to February 2022 were collected. The patients were divided into an endoscopic group and a laparoscopic group according to the surgical method. The clinical data and tumor recurrence information were compared between the two groups. RESULTS: Eighteen cases were collected in the endoscopic group and sixty-three cases in the laparoscopic group. There were no significant differences in age, gender, tumor diameter, tumor growth site, tumor growth mode, clinical manifestations, risk classification or complication rate between the two groups (P > 0.05). The hospitalization cost, length of postoperative hospital stay and postoperative fasting time of the endoscopic group were less than those of the laparoscopic group, while the operation time was greater than that of the laparoscopic group (P < 0.05). In the endoscopic group, the follow-up was 33.50 ± 19.410 months, and no patients were lost to follow-up. The laparoscopic group was followed up for 59.07 ± 12.964 months, and eleven patients were lost to follow-up. There was no recurrence or metastasis in the two groups during the follow-up. CONCLUSION: Endoscopic resection of gastric GIST with a diameter ≥5 cm is technically feasible. And it not only achieves a short-term prognosis similar to laparoscopic resection but also has the advantages of rapid postoperative recovery and low cost.

Diagnostic and prognostic role of circRNAs in pancreatic cancer: a meta-analysis.

Background: Circular RNAs (circRNAs) are types of endogenous noncoding RNAs produced by selective splicing that are expressed highly specifically in various organisms and tissues and have numerous clinical implications in the regulation of cancer development and progression. Since circRNA is resistant to digestion by ribonucleases and has a long half-life, there is increasing evidence that circRNA can be used as an ideal candidate biomarker for the early diagnosis and prognosis of tumors. In this study, we aimed to reveal the diagnostic and prognostic value of circRNA in human pancreatic cancer (PC). Methods: A systematic search for publications from inception to 22 July 2022 was conducted on Embase, PubMed, Web of Science (WOS), and the Cochrane Library databases. Available studies that correlated circRNA expression in tissue or serum with the clinicopathological, diagnostic, and prognostic values of PC patients were enrolled. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to evaluate clinical pathological characteristics. Area under the curve (AUC), sensitivity, and specificity were adopted to assess diagnostic value. Hazard ratios (HRs) were utilized to assess disease-free survival (DFS) and overall survival (OS). Results: This meta-analysis enrolled 32 eligible studies, including six on diagnosis and 21 on prognosis, which accounted for 2,396 cases from 245 references. For clinical parameters, high expression of carcinogenic circRNA was significantly associated with degree of differentiation (OR = 1.85, 95% CI = 1.47-2.34), TNM stage (OR = 0.46, 95% CI = 0.35-0.62), lymph node metastasis (OR = 0.39, 95% CI = 0.32-0.48), and distant metastasis (OR = 0.26, 95% CI = 0.13-0.51). As for clinical diagnostic utility, circRNA could discriminate patients with pancreatic cancer from controls, with an AUC of 0.86 (95% CI: 0.82-0.88), a relatively high sensitivity of 84%, and a specificity of 80% in tissue. In terms of prognostic significance, carcinogenic circRNA was correlated with poor OS (HR = 2.00, 95% CI: 1.76-2.26) and DFS (HR = 1.96, 95% CI: 1.47-2.62). Conclusion: In summary, this study demonstrated that circRNA may act as a significant diagnostic and prognostic biomarker for pancreatic cancer.

Molecular landscape and clinical significance of exon 11 mutations in KIT gene among patients with gastrointestinal stromal tumor: a retrospective exploratory study.

Objective: This aim of this study was to investigate the prognostic significance of KIT exon 11 mutation subtypes in patients with GISTs. Methods: A total of 233 consecutive patients diagnosed with GISTs at the First Affiliated Hospital of Zhengzhou University from January 2013 to August 2018 were included in this study. The prevalence and mutation landscape of exon 11 in KIT was presented. The clinicopathological characteristics and prognosis among the different mutation subtypes were analyzed. All the statistical analyses were performed by SPSS22.0. Results: Somatic mutational analysis indicated that point mutations were the most frequently detected mutations followed by deletions & compound mutations and insertion and tandem duplication mutations in the stomach. Point mutations showed a low mitotic count and a high risk of recurrence, and deletions and compound mutations have a high mitotic count while insertions and tandem duplication mutations showed a low mitotic count with an intermediate recurrence risk. Point mutations and deletions frequently occurred in sequence region codons 550-560 of exon 11, while compound mutations, insertion, and tandem duplication were mainly detected in codons 557-559, 572-580, and 577-581, respectively. The multi-variation analysis demonstrated that tumor diameter and high recurrence risk groups had worse prognostic values. However, mutation types were not significant predictors of relapse-free survival (RFS) in GISTs. Survival analysis suggested no significant difference in RFS between the 557/558 deletion and the other deletions. Conclusion: This study suggested that mutations in exon 11 of the KIT gene were common with intermediate/high recurrence risk in GISTs patients. Tumor diameter ≥5 cm, and deletions mutations might predict a worse prognosis.

Effect of Abdominal Compression on Total Single-Balloon Enteroscopy Rate: A Randomized Controlled Trial.

OBJECTIVE: To evaluate whether abdominal compression significantly increased the total enteroscopy rate in single-balloon enteroscopy (SBE). METHODS: Consecutive patients who underwent SBE at 2 hospitals were prospectively included between June 1, 2020, and September 30, 2021. They were randomly divided into an abdominal compression group and a non-abdominal compression group with use of sealed envelopes generated by a computer. Total enteroscopy rates were compared between the groups. RESULTS: The study included 200 patients. The total enteroscopy rates were 73% and 16% in the abdominal compression and non-abdominal compression groups, respectively (relative risk, 13.55; 95% CI, 6.79 to 27.00; P<.001). The total enteroscopy rate was higher in the 70 patients who were identified to have undergone no previous abdominal surgery or small intestinal stenosis than in the 32 patients who had undergone such procedures in the abdominal compression group (84% vs 47%; relative risk, 6.08; 95% CI, 2.36 to 15.67; P<.001). Relevant positive findings were not significantly different between the groups (58% vs 45%; P=.07). Binary logistic regression analysis found abdominal compression to be associated with a better total enteroscopy rate (odds ratio, 16.68; 95% CI, 7.92 to 35.15; P<.001), and the presence of previous abdominal surgery or small intestinal stenosis was associated with difficulty in completing the total enteroscopy procedure (odds ratio, 0.26; 95% CI, 0.12 to 0.58; P<.01). CONCLUSION: Abdominal compression significantly increased the total enteroscopy rate in SBE. Complete total enteroscopy may be challenging in patients with a history of abdominal surgery or small intestinal stenosis.

Gastric cancer cell-derived extracellular vesicles elevate E2F7 expression and activate the MAPK/ERK signaling to promote peritoneal metastasis through the delivery of SNHG12.

Cancer cell-derived extracellular vesicles (EVs) have extensive application in the formation of their environment, including metastasis. This study explored the ability of gastric cancer (GC) cell-derived EVs-mediated microRNA-129-5p/E2F transcription factor 7/mitogen-activated protein kinase/extracellular regulated protein kinase (miR-129-5p/E2F7/MAPK/ERK) axis to affect the peritoneal metastasis of GC by delivering lncRNA small nucleolar RNA host gene 12 (SNHG12). EV-derived lncRNA and SNHG12/miR-129-5p/E2F7 network were determined by bioinformatics analysis. The regulatory relationship among SNHG12, miR-129-5p, and E2F7 was verified using a combination of dual-luciferase reporter gene, RNA immunoprecipitation, and RNA pull-down assays. The SNHG12, miR-129-5p, and E2F7 expression was measured by RT-qPCR. After GC cell-derived EVs were isolated and co-cultured with human peritoneal mesothelial cells (HPMCs), the uptake of EVs by HPMCs was observed under laser scanning confocal microscopy. Cell viability and apoptosis were examined using cell counting kit-8 and flow cytometry, respectively. Western blot analysis was performed to measure the mesothelial-mesenchymal transition (MMT)-related protein expression. The pathological and morphological characteristics of metastatic tumors in nude mice were observed by hematoxylin-eosin staining. A high SNHG12 expression was correlated with the poor prognosis of patients with GC. GC-derived EVs led to increased HPMC apoptosis and MMT by transferring SNHG12, whereas the knockdown of SNHG12 annulled the aforementioned results. SNHG12 sponged miR-129-5p to boost E2F7 expression and activate the MAPK/ERK signaling, thus inducing HPMC apoptosis and MMT. In vivo experiments further verified that EVs derived from GC cells promoted peritoneal metastasis in nude mice. GC cell-derived EVs elevated the E2F7 expression and activated the MAPK/ERK signaling to promote peritoneal metastasis through the delivery of SNHG12.

miR-137 is frequently down-regulated in gastric cancer and is a negative regulator of Cdc42.

INTRODUCTION: MicroRNAs (miRNAs) are a class of small (19-25 nucleotides) noncoding RNAs that regulate the expressions of a wide variety of genes, including some involved in cancer development. Some recent studies show that DNA methylation contributes to down-regulation of microRNA-137 (miR-137) during tumorigenesis. Whether down-regulation of miR-137 also exists in gastric cancer is unknown. AIM: Our aim was to test the hypothesis that down-regulation of miR-137 also exists in gastric cancer. METHODS: Expression of levels of miR-137 were examined using real-time PCR on paired gastric cancer and adjacent non-cancerous tissues. The methylation status is detected by MSP. RESULTS: Results show that miR-137 is downregulated by hypermethylation of the promoter in gastric cancer tissues. Epigenetic silencing of miR-137 induced an up-regulation of its targets, Cdc42. Restoration of the miR-137 expression in gastric cancer cell lines downregulated the Cdc42 expression. Restoration of the miR-137 and inactivation of Cdc42 induce apoptosis and cell cycle G1 arrest in gastric cancer cells. Furthermore, the miR-137 expression was found to be inversely correlated with CDC42 expression in gastric caner. CONCLUSIONS: miR-137 is frequently down-regulated in gastric cancer and is a negative regulator of Cdc42.

Methylation of microRNA-338-5p by EED promotes METTL3-mediated translation of oncogene CDCP1 in gastric cancer.

Unmasking the complex regulatory pathways that mediate the malignant phenotypes of cancer cells can provide novel targets for therapies that could limit the recurrence and metastasis of gastric cancer (GC). Herein, we intended to clarify the role of embryonic ectoderm development protein (EED), microRNA-228-5p (miR-338-5p), methyltransferase like 3 (METTL3) and CUB domain containing protein 1 (CDCP1) in GC. Differentially expressed miRNAs and their target genes were extracted by in silico analysis. The studies revealed high expression of EED in GC tissues and cell lines and it high expression in GC patients was shown to be associated with poor prognosis. The chromatin immunoprecipitation assay identified that EED methylated miR-338-5p to inhibit its expression. EED knockdown could restrain the proliferative and invasive abilities of GC cells by inducing miR-338-5p. Furthermore, miR-338-5p targeted m6A methylase METTL3, while METTL3 amplified the translation of CDCP1 via m6A activity which led to accelerated proliferation and invasion of GC cells. Moreover, in vivo experiments validated that EED promoted the progression of GC through mediating the miR-338-5p/METTL3/CDCP1 axis. Collectively, EED downregulated miR-338-5p through histone methylation, which in turn impaired miR-338-5p-dependent METTL3 inhibition and enhanced CDCP1 translation, therefore contributing to the development of GC.

Novel Pt(IV) complexes to overcome multidrug resistance in gastric cancer by targeting P-glycoprotein.

Systematic toxicity and drug resistance significantly limited FDA-approved platinum drugs for further clinical applications. In order to reverse the resistance (MDR) and enhance their anticancer efficiency, four Pt(IV) complexes (12-15) conjugating with P-glycoprotein (P-gp) inhibitors were designed and synthesized. Among them, complex 14 (IC50 = 3.37 µM) efficiently reversed cisplatin resistance in SGC-7901/CDDP cell line and increased selectivity index (6.9) against normal HL-7702 cell line. Detailed mechanisms in SGC-7901/CDDP cells assays revealed that complex 14 efficiently induced apoptosis via down-regulating expression of P-gp for enhanced intracellular uptake of platinum, arrested cells at G2/M phase, induced DNA damage and initiated mitochondrial apoptosis pathway. Further in vivo studies demonstrated that the enhanced accumulation of complex 14 contributed to tumor inhibition of 75.6% in SGC-7901/CDDP xenografts, which was much higher than cisplatin (25.9%) and oxaliplatin (43%). Moreover, the low systematic toxicity made 14 a potential novel P-gp-mediated MDR modulator.

[Ecological resilience of ancient Pinus massoniana trees to climate change and insect infestation in southeastern Fujian, China]. / é—½ä¸œå—åœ°åŒºé©¬å°¾æ¾å¤æ ‘å¯¹æ°”å€™å˜åŒ–å’Œè™«ç¾çš„ç”Ÿæ€å¼¹æ€§.

Pinus massoniana is a typical pioneer afforestation tree species widely distributed in southern China. It is crucial to study the ecological resilience of P. massoniana to disturbances under global warming, drying, and frequent pest infestation, which can shed lights on forest mana-gements. In this study, tree-ring samples collected from old-growth P. massoniana trees in Baisong Village, Xianyou County, Fujian Province, were used to develop the first standard chronology of P. massoniana ring width (1865-2014) in this region. The results showed that the low relative humidity from July to September and the extremely high temperature from May to September were the main limiting factors for tree growth. The extremely narrow years were identified in 1869, 1889, 1986, 1991 and 1993. These extremely narrow years were exacerbated after the persistently low values of the previously two years via the superposed epoch analysis (SEA). The insect infestations were more likely to happen in dry years. Insect outbreak exerted strongest effect on tree growth in 1889. The narrow tree-rings in 1986 and 1991 were affected by both insect infestation and drought. The other extremely narrow years were mainly affected by drought. The resistance of trees to insect infestation was weaker than that to drought event. The relative resilience of trees to insect infestation was higher than that to drought event, except for 1991. The relative resilience was the highest in 1889 and the lowest in 1991 under the influence of successive extreme events. Under the enhanced drying trend since 2000, more trees had died possibly due to the combined effects of insect infestation and drought.

[Differences in the ecological resilience of planted and natural Pinus massoniana and Cunninghamia lanceolata forests in response to drought in subtropical China]. / 亚热带人工和天然马尾松、杉木林生长对干旱的生态弹性差异.

We sampled Pinus massoniana and Cunninghamia lanceolata in both plantation and natural forests in central and western Fujian Province, China. Using tree-ring width, tree-ring width index, and basal area increment, we reconstructed the annual growth of 109 conifer individuals from four sites for the 20-year period from 1993 to 2012. We then calculated resistance, recovery, and resilience indices of those trees in response to two consecutive extreme droughts (2003-2004 and 2011) and analyzed the differences in resistance and resilience between plantations and natural fore-sts. The results showed that there were temporal differences in moisture requirements between P. massoniana and C. lanceolata, which accounted for their inconsistent responses to drought in 2003-2004. For both species, drought induced a marked growth reduction, without any clear lag effect. The growth responses during and following the 2003-2004 drought were significantly stronger than that for the 2011 drought. Those results indicated that P. massoniana was more resilient to drought stress than C. lanceolata, and the natural forests were more sensitive than plantations, but with stronger capacity to recover. C. lanceolata plantations were more susceptible to frequent extreme drought events. To mitigate the vulnerability of plantation trees to more frequent droughts in the future, we suggested select trees from genetic provenances with strong drought resistance.

Cystatin M expression is reduced in gastric carcinoma and is associated with promoter hypermethylation.

Cystatin M is a secreted inhibitor of lysosomal cysteine proteases and increasing evidences indicate that it is a novel target for epigenetic silencing during mammary tumorigenesis. Aberrant promoter methylation is a well-known mechanism that participates in cystatin M silencing in breast cancer. However, the role of cystatin M in the gastric cancer remains to be elucidated. Immunohistochemistry was used to investigate the expression of cystatin M in 60 gastric carcinomas. Hypermethylation of cystatin M promoter was evaluated by the methylation-specific PCR (MSP) method in gastric carcinomas (tumor and paired adjacent non-tumor tissues). Reverse-transcriptase PCR and BSP were also performed on gastric cancer cell lines before and after treatment with 5-aza-2'-deoxycytidine (5-Aza-dC). Lost expression of cystatin M was observed in 42 of 60 (70%) gastric carcinomas. 55% (33 of 60) of primary tumors analyzed displayed cystatin M promoter hypermethylation, indicating that this aberrant characteristic is common in gastric malignancies. Moreover, a statistically significant inverse association was found between cystatin M methylation status and expression of the cystatin M protein in tumor tissues (p=0.027). We also found that patients with cystatin M promoter methylation had a significantly shorter survival time than those without this methylation (p=0.020). These results suggest that cystatin M promoter hypermethylation is one of the molecular mechanisms that accounts for reduced cystatin M gene expression in gastric carcinomas.

Expression of TIP30 tumor suppressor gene is down-regulated in human colorectal carcinoma.

PURPOSE: Human TIP30 was initially identified as a candidate metastasis suppressor gene whose expression was down-regulated in human liver, lung, breast, and prostate cancers, and recently the role of this gene was examined in colorectal cancer. The aim of this study was to determine the level of TIP30 expression in colorectal carcinoma (CRC). RESULTS: TIP30 protein levels were lower in colorectal carcinomas compared to normal tissue from the control group (P < 0.001). The frequencies of hypermethylation of TIP30 in tumor were 36%, while there was no aberrant methylation in paired adjacent non-tumor tissue. A statistically significant inverse association was found between TIP30 methylation status and expression of the TIP30 protein in tumor tissues (P = 0.006). Somatic missense mutations in the TIP30 gene were identified in human CRC tissue specimens. CONCLUSIONS: Our results demonstrate that promoter methylation is involved in the decreased expression of TIP30 tumor suppressor gene in human colorectal carcinoma.