Chung-Wei Fan

Comparison of KRAS mutation analysis of primary tumors and matched circulating cell-free DNA in plasmas of patients with colorectal cancer

Colorectal cancer (CRC) patients with KRAS mutations do not benefit from epidermal growth factor receptor (EGFR) targeted therapy. In clinical practice, identifying patients with KRAS mutations is critical prior to EGFR targeting therapy, and gene testing is generally performed using the DNA extracted from tumor tissue. The aim of this study was to compare the presence of KRAS mutations in circulating cell-free DNA (cfDNA) and primary tumor tissue using a peptide nucleic acid mediated polymerase chain reaction. We extracted and analyzed the DNA from plasmas and corresponding primary tumor samples from 52 patients with CRC. The results demonstrated that the detection rate of KRAS sequence variations was 50% (26 of 52) in plasma samples and 28.8% (15 of 52) in resected primary tumor tissue samples. The majority of KRAS mutations detected in tumors were also found in matched plasma specimens with an agreement rate of 78.8%. Eleven plasma cfDNA were found positive for KRAS mutation but not in their corresponding tissue. In conclusion, our results suggest that circulating cfDNA provides a better representation of the malignant disease as a whole and could be a reliable source of diagnostic DNA to replace the tumor tissue in a diagnostic setting.

Inverse Effects of Mucin on Survival of Matched Hereditary Nonpolyposis Colorectal Cancer and Sporadic Colorectal Cancer Patients

Purpose: To compare survival and histologic features of hereditary nonpolyposis colorectal cancer (HNPCC; Lynch syndrome) cases to well-matched sporadic colon cancers from the same patient population. Experimental Design: Between January 1995 and March 2002, a total of 5,138 consecutive patients underwent resection of primary colorectal adenocarcinoma in a single institution. According to the Amsterdam criteria, 56 HNPCC patients were matched to 147 sporadic colorectal cancer (SCRC) with no family history of cancer and with the same gender, tumor location, and age within 3 years. Immunohistochemical analyses were done for MUC1, MUC2, MUC3, and MUC5AC. Results: The HNPCC group had a marginally significantly better long-term outcome than the SCRC group (P = 0.058). The trend disappeared after adjustment by tumor-node-metastasis stage in a Cox model (P = 0.774). We noted a difference of >50% in the 5-year cancer-specific survival rates of HNPCC- and SCRC-mucinous groups (92% versus 31%, P = 0.0003). Interaction between mucin and HNPCC and its effects on survival were further confirmed by comparing the Cox models with and without interaction terms (hazard ratio, 0.1; P = 0.034 with adjusting stage). Patients with tumors showing dual expression of mucin and MUC1, which appeared in 11% of those with HNPCC and 50% of those with SCRC, had a lower 5-year cancer-specific survival rate than patients without (30% versus 60%; P = 0.004 by log-rank test; P = 0.039 with adjustment for tumor-node-metastasis stage). Conclusions: These results suggest that mucin has an inverse effect on survival in patients with HNPCC and SCRC, which might be partly explained by a lower prevalence of MUC1 expression in the mucinous HNPCC group than in the SCRC groups.

Down-regulation of matrix Gla protein messenger RNA in human colorectal adenocarcinomas

Matrix Gla protein (MGP) is a vitamin K-dependent extracellular matrix protein commonly found in a variety of tissues. In this study, we describe the potential use of MGP gene expression as the tumor marker of colorectal cancer. A decrease in expression of the MGP gene was also discovered in colorectal cancer using differential screening of cDNA libraries. The MGP expression in 80 human colorectal adenocarcinomas was quantified by a Northern blot analysis to better define the expression pattern of MGP in colorectal cancer. The expression of MGP mRNA was reduced in 63 of 80 (79%) colorectal adenocarcinomas (P<0.001) as compared to the mRNA in adjacent normal tissue, implying that a decrease in MGP expression is associated with colorectal cancer development. The proportion of tumors with downregulated expression of MGP was lower in Dukes A/B than Dukes C/D (34 of 47 versus 26 of 33, respectively) tumors and was lower in moderate differentiation than poor differentiation (44 of 64 versus 16 of 16, respectively). However, chi(2) analysis does not reveal any correlation between a loss of MGP expression and tumor progression or differentiation state. In conclusion, the downregulation of MGP mRNA generally occurs in colorectal adenocarcinomas. Although the role of MGP in cancer development is unknown, the reduced expression of MGP may be used to distinguish the normal colorectal cells from malignant cells.

Effect of Body Mass Index on the Outcome of Patients With Rectal Cancer Receiving Curative Anterior Resection: Disparity Between the Upper and Lower Rectum

Objective:The aim of this study was to investigate the effect of body mass index (BMI) on local recurrence of primary rectal cancer after open curative sphincter-saving resection. Background:Increasing BMI was reported to be associated with a higher likelihood of local recurrence in male patients with rectal cancer. However, it remained unclear whether BMI exerts the same effects on local recurrence of rectal cancer in the upper and lower rectum. Methods:Between January 1995 and December 2002, we investigated 1873 patients with well-documented body height and body weight who underwent curative anterior resection for primary rectal cancer in a single institution. The patients were assigned to 4 groups according to their BMI: underweight, normal, overweight, and obese. Results:The frequency of local recurrence increased with an increase in the BMI in patients with lower rectal cancer. The local recurrence rates were 2.5% (2 of 79), 6.1% (48 of 782), 9.2% (39 of 424), and 13.8% (9 of 65) in underweight, normal, overweight, and obese patients with lower rectal cancer, respectively. These results were different from those of patients with upper rectal cancer. Independent risk factors for local recurrence in the lower rectal cancer group were BMI, resection margin, histologic grade of differentiation, depth of tumor invasion, and status of lymph node metastases. In the upper rectal cancer group, the depth of tumor invasion and histologic grade of differentiation reached statistical significance. Conclusions:BMI exerted different effects on local recurrence of rectal cancer in the upper and lower rectum. Further, more aggressive adjuvant and/or neoadjuvant treatments should be considered for patients with tumor in the lower rectum and with higher BMI.

Expression patterns of cell cycle and apoptosis-related genes in a multidrug-resistant human colon carcinoma cell line.

Background: An in vitro multidrug resistance (MDR) system from a human colonic cancer cell line (SW620‐MDR) has been established. To further study the mechanisms at molecular level and prevention of multidrug resistance in clinical practice, it was demonstrated that the expressions of several apoptosis‐related and cell cycle regulator genes were changed in the cells. Methods: A multidrug‐resistant colonic cell line (SW620‐MDR) was established, and the Atlas human cDNA expression array was used for studying the pattern of gene expression in this cell line. Furthermore, Northern hybridization or real‐time PCR analysis confirmed the pattern of gene expression. Results: In the SW620‐MDR cell line the pro‐apoptosis genes, CASP4, BIK, PDCD2, and TACE were expressed with decreased levels, and the anti‐apoptosis genes CD27‐L and IGFBP2 were over‐expressed. Furthermore, the cell cycle regulator genes such as CDK6, CCND1, CDC27HS, CDC16HS, Wee1Hu, MAPKK1, and IGFBP6 were expressed with decreased levels in the drug‐resistant cell line. Conclusions: It is worthwhile investigating whether the differentially expressed pattern of the aforementioned genes exists in the drug‐resistant cancer specimens, and to further understand their functions in the cancer drug‐resistance mechanism.

Detection of autoantibodies against Rabphilin-3A-like protein as a potential biomarker in patient's sera of colorectal cancer.

BACKGROUND Rabphilin-3A-like (RPH3AL) protein functions in the regulation of hormone exocytosis, and mutations in the RPHA3L gene have been associated with tumorigenesis in colorectal cancer (CRC). We evaluated the potential use of anti-RPH3AL autoantibodies as a marker for CRC detection. METHODS Sera from 84 patients with CRC and 63 healthy controls were analysed for the presence of RPH3AL autoantibodies with a Western blotting assay. RESULTS The frequencies of RPH3AL autoantibodies in the early stage, advanced stage and all CRC patients were 64.7%, 78.0% and 72.6%, respectively. These values are significantly higher than the frequency of RPH3AL autoantibodies in healthy controls (15.9%, P<0.001). Although the presence of RPH3AL autoantibodies did not correlate with clinical parameters, RPH3AL autoantibodies were found in 69.4% (34/49) of CRC patients who were negative for carcinoembryonic antigen. The value of the area under the receiver operating characteristic curve of RPH3AL autoantibody was 0.84, which suggests that screening for these autoantibodies could potentially be used for CRC diagnosis. CONCLUSION Circulating RPH3AL autoantibodies are prevalent in patients with CRC, and detection of these autoantibodies might provide a novel non-invasive approach for CRC diagnosis.

Blockade of phospholipid scramblase 1 with its N-terminal domain antibody reduces tumorigenesis of colorectal carcinomas in vitro and in vivo

BackgroundMembrane-bound phospholipid scramblase 1 (PLSCR1) is involved in both lipid trafficking and cell signaling. Previously, we showed that PLSCR1 is overexpressed in many colorectal carcinomas (CRCs). In the present study, we investigated the tumorigenic role of PLSCR1 in CRC and suggest that it is a potential therapeutic target.MethodsTo identify PLSCR1 as a therapeutic target, we studied the tumorigenic properties of CRC cell lines treated with a monoclonal antibody (NP1) against the N-terminus of PLSCR1 in vitro and in vivo. We also investigated cell cycle status and epidermal growth factor receptor–related pathways and downstream effectors of PLSCR1 after blocking its function with NP1.ResultsTreating CRC cells with NP1 in vitro and in vivo decreased cell proliferation, anchorage-independent growth, migration, and invasion. Adding NP1 to the CRC cell line HT29 caused arrest at G1/S. Treating HT29 cells with NP1 significantly decreased the expression of cyclin D1 and phosphorylation levels of Src, the adaptor protein Shc, and Erks. The reduced level of cyclin D1 led to an increase in the activated form of the tumor suppressor retinoblastoma protein via dephosphorylation. These actions led to attenuation of tumorigenesis.ConclusionsTherefore, PLSCR1 may serve as a potential therapeutic target for CRC.

Massive hematochezia from acute hemorrhagic rectal ulcer in patients with severe comorbid illness: rapid control of bleeding by per anal suturing of bleeder using anoretractor.

PurposeMassive hematochezia from acute hemorrhagic rectal ulcer can arise in patients with severe comorbid illness who are bedridden for long periods. If the bleeder is not found and treated immediately, the bleeding will cause deterioration of health and even threaten life. The results of the current study show how quickly and safely per anal suturing can treat acute hemorrhagic rectal ulcer.MethodsFrom January 2003 to December 2003, the records of 26 patients who underwent per anal suturing of acute hemorrhagic rectal ulcer were retrospectively reviewed. The identification of acute hemorrhagic rectal ulcer was confirmed by clinical and anoscopic examination.ResultsMost of these patients were elderly and bedridden (14 men; median age 69 years). Main comorbid illnesses existed in all patients and included liver cirrhosis (8 patients, 31 percent), sepsis (13 patients, 50 percent), cerebral vascular accident (15 patients, 58 percent), respiratory failure (13 patients, 50 percent), and malignancy (7 patients, 27 percent). Effective hemostasis was achieved in all patients by direct suture of bleeding ulcer. No complications developed relative to the per anal suturing procedure among any patients. Although 11 patients developed recurrent hematochezia, 9 patients responded to repeated therapy. The risk factors associated with recurrent bleeding were severity of disease and abnormal coagulation.ConclusionsWhen massive hematochezia occurs in bedridden patients with severe comorbid illness, it is essential to investigate the lower rectum, which often is affected by acute hemorrhagic rectal ulcer. Recognition of this clinical presentation will result in early identification and therapy. Per anal suturing of a bleeder at the bedside provides a quick, safe, and successful management of acute hemorrhagic rectal ulcer.

The Ratio of Hmox1/Nrf2 mRNA Level in the Tumor Tissue Is a Predictor of Distant Metastasis in Colorectal Cancer

Heme oxygenase 1 (Hmox1) plays an important role in the growth and spread of tumor, and its expression is regulated positively by Nrf2 [nuclear factor (erythroid-derived 2)-like 2; NFE2L2] and negatively by kelch-like ECH-associated protein 1 (Keap1) and by BTB and CNC homology 1 (Bach1). Both Hmox1 and Nrf2 contribute to distant metastasis of cancer. The mRNA levels of Hmox1, Nrf2, Keap1, and Bach1 in the tumor and normal tissues of 84 subjects with colorectal cancer (CRC) were determined by real-time polymerase chain reaction. The tumor had lower Hmox1 but higher Bach1 mRNA levels than the normal tissue. The correlations of Hmox1 with components of the Nrf2 pathway were not significant in the tumor tissue of CRC subjects with distant metastasis. The ratio of Hmox1/Nrf2 mRNA level (by percentage) in the tumor tissue was lower in the subjects with distant metastasis (97.4% (84.4–111.1%)) than in those without (101.0% (92.7–136.5%)) and was a predictor for distant metastasis in CRC (odds ratio: 0.83; 95% confidence interval: 0.68–0.97) along with serum carcinoembryonic antigen (1.0027, 1.006–1.064). The mRNA level of Hmox1 in the tumor tissue of CRC is not correlated with that of the Nrf2 pathway molecules, and its ratio to the Nrf2 level may be useful for suggesting distant metastasis in CRC.

Sebacoyl Dinalbuphine Ester Extended-release Injection for Long-acting Analgesia: A Multicenter, Randomized, Double-blind, And Placebo-controlled Study in Hemorrhoidectomy Patients

Objectives: This study was conducted to evaluate the safety and efficacy of single sebacoyl dinalbuphine ester (SDE) injection (150 mg/2 mL) when administered intramuscularly to patients who underwent hemorrhoidectomy for postoperative long-acting analgesia. Methods: A total of 221 patients scheduled for hemorrhoidectomy from 6 centers in Taiwan were randomly divided into SDE group and placebo group, and received the treatment, vehicle or SDE, 1 day before the surgery. Visual analogue scale (VAS) was recorded up to 7 to 10 days. Pain intensity using VAS AUC through 48 hours after surgery was calculated as the primary efficacy endpoint. Results: Area under the curve of VAS pain intensity scores (VAS AUC) through 48 hours after hemorrhoidectomy was significantly less in SDE group than those in placebo group (209.93 vs. 253.53). VAS AUC from the end of surgical procedure to day 7 was also significantly different between SDE and placebo group (630.79 vs. 749.94). SDE group consumed significantly less amount of other analgesics, such as PCA ketorolac and oral ketorolac. Median time from the end of surgery to the first use of pain relief medication was also shortened in the placebo group than in the SDE group. Most adverse events were assessed as mild and tolerable in both groups. Discussion: SDE injection demonstrated an extended analgesia effect, with a statistically significant reduction in pain intensity through 48 hours and 7 days after hemorrhoidectomy.