Ryung-Ah Lee

Overexpression of phospholipase D1 in human breast cancer tissues

Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine (PC) to produce phosphatidic acid (PA) and choline. PLD is a major enzyme implicated in important cellular processes, such as cell proliferation. We designed this study to investigate the expression of PLD in human breast carcinomas and non-malignant tissues using RT-PCR, Western blot analysis, immunohistochemistry and an Arf-dependent PLD activity assay. We examined about 550 bp of PCR product and 120 kDa of PLD protein. Our results showed that PLD protein and mRNA levels were overexpressed in 14 of 17 breast cancer tissues. We also observed increased expression by immunohistochemistry and Arf-dependent PLD activity in microsomes of human breast tumors, which correlated well with PLD expression. PLD expression was elevated in human breast tumors compared with normal breast tissues. These results implicate a possible role of PLD in human breast tumorigenesis and suggest that PLD may be useful as a marker for malignant disease in the breast.

Overexpression of βPix-a in human breast cancer tissues

Pak interacting exchange factor (βPix) is a recently cloned protein that contains a multidomain with many potential binding sites and is known to be involved in the regulation of Cdc42/Rac GTPases and Pak kinase activity. These domains of βPix appear to play a critical role in the regulation of the cytoskeletal organization. The overexpression of βPix enhances the activation of p38, which is thought to be an important downstream effector of the Rho GTPase family (Rac, Cdc42), which are involved in increased membrane ruffling and cell motility. This increase of cell mobility is an important feature of cancer invasion. We examined the expression of βPix-a in human breast cancer tissues and adjacent normal tissues obtained from 39 breast cancer patients. Immunoblot analysis and RT-PCR revealed that βPix-a expression was significantly increased in 37 of the 39 breast cancer tissues (94.9%) versus normal breast tissues. Immunohistochemical analysis showed that breast cancer tissues have consistently stronger immunoreactivity to βPix-a antibodies than normal tissues. βPix-a overexpression was inversely associated with extensive intraductal component (P<0.001). In conclusion, βPix-a expression was found to be higher in human breast cancer tissues than in normal breast tissues, which implies a role for βPix-a in human breast tumorigenesis. We suggest that βPix-a may be a useful marker of malignant disease in the breast.

siRNA targeting Livin decreases tumor in a xenograft model for colon cancer

AIM To evaluate the effect of silencing Livin gene expression with siRNA to apoptosis and proliferation in a colon cancer cell line. METHODS To investigate the anticancer effect of silencing Livin gene expression, we established an siRNA transfected cell line using the HCT116 colon cancer cell line. After confirming the successful transfection, MTT assay, flow cytometry and annexin V staining were employed to evaluate the antiapoptotic effect. To confirm the in vivo effect of Livin-siRNA, different doses of Livin-siRNA were injected into xenografted tumors in BALB/c nude mice model. RESULTS Livin expression was dramatically decreased after siRNA transfection, especially at 25 μmol/L of siRNA, but this suppression was not dose-dependent. The cell count at 18 h after transfection was significantly reduced as compared with controls (P < 0.01), but tended not to decrease proportionally depending on transfected dose or time. MTT assay revealed that silencing the Livin gene suppressed cellular proliferation at 18 h after transfection (P = 0.04); however, the inhibitory effect disappeared thereafter. Also, there was no significant difference in cellular proliferation depending on siRNA dose. The rate of apoptosis also increased with silencing of the Livin gene. In vivo, the tumor size significantly decreased after Livin-siRNA injection at 20 μmol/L concentration (P = 0.03). There were no significant body weight changes of mice after siRNA injection. Histologic examination revealed no significant toxic reaction in kidney, liver and brain of mice. CONCLUSION siRNA-mediated downregulation of Livin expression can induce apoptosis in colon cancer in vitro and in vivo, which suggests the possibility of new cancer therapeutics using siRNA.

Induction of apoptosis with diallyl disulfide in AGS gastric cancer cell line

Purpose Diallyl disulfide (DADS) is a major organosulfur compound derived from garlic. It has been reported that DADS is able to inhibit the proliferation of several tumor cells. In this study, the effect of DADS was investigated in terms of the proliferation of AGS, gastric adenocarcinoma cell line at various concentrations. Methods The viability of cultured cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. To detect the induction of apoptosis, Annexin V-FITC/propodium iodide (PI) staining assay was performed. Analysis of reactive oxygen species (ROS) and the distribution of cells in the cell cycle were measured by a flow cytometer. And using the Western blot analysis, the change of Fas, caspase-3, Bax, Bcl-2 activity was measured. Results The percentage of live AGS cells was decreased to 23% of that in the control group after 400 µM DADS treatment for 48 hours. The Annexin V positive/PI negative (apoptosis portion) area increased from low concentration of DADS to high concentration. When comparing among the DADS treatment groups, the amount of ROS production increased in a dose dependent manner. The percentage of sub-diploid DNA content increased from 8.71% at 50 µM to 25.74% at 400 µM DADS treatment group. The expressions of Fas, caspase-3, Bax were increased and that of Bcl-2 was decreased in a dose dependent manner. Conclusion DADS decreases the viability of AGS cell lines and induces apoptosis in a dose-dependent manner. But the relationship of the anti-proliferative effect of DADS and related molecular changes were not clearly proportional to the concentration of DADS.

Metastasis to the breast from colonic adenocarcinoma

A 63-year-old woman was referred to a breast surgeon with a breast mass discovered incidentally during follow-up study after colon cancer surgery. Invasive adenocarcinoma was revealed on core needle biopsy. Wide excision of the breast including the tumor was performed. On standard histological examination the tumor showed features of moderately differentiated adenocarcinoma. The immunohistochemistry study revealed positive results for cytokeratin (CK)20 and CDX2, but negative for CK7. These are typical characteristics for colon cancer. Considering her history of subtotal colectomy for sigmoid colon cancer, it is presumable that the mass in the breast was of colonic origin, and it was an extremely rare case of metastasis to the breast from primary colorectal neoplasm. Although the instance is rare, clinicians should keep the possibility of breast metastasis from colorectal cancer in mind for early and correct diagnosis.

Acute hyperammonemic encephalopathy after 5-fluorouracil based chemotherapy

5-Fluorouracil (5-FU) based chemotherapy has been commonly used to treat metastatic or advanced colon cancer as an adjuvant chemotherapy. Although the side effects of 5-FU such as gastrointestinal problems and neutropenia and thrombocytopenia are common, not many cases of 5-FU related encephalopathy are reported. Hyperammonemic encephalopathy is a rare central nervous system toxicity following 5-FU chemotherapy manifesting as altered mental status with elevated ammonia levels with no radiologic abnormality. We report one case of 5-FU induced hyperammonemic encephalopathy occurring after Folfox4 (oxaliplatin, folinic acid and 5-fluorouracil) chemotherapy in a colon cancer patient who presented with confused mental status soon after the chemotherapy and review the 5-FU related encephalopathy.

Optimal Time of Initiating Adjuvant Chemotherapy After Curative Surgery in Colorectal Cancer Patients

Purpose Adjuvant chemotherapy is routinely recommended for locally advanced colorectal cancer (CRC). There are very few data for the optimal starting date of adjuvant chemotherapy after the surgery. This study aimed to evaluate the effectiveness of earlier adoption of adjuvant chemotherapy after curative surgery for stage III CRC. Methods In this study, 159 patients with stage III CRC, who had undergone a curative resection, were enrolled retrospectively. Patients were categorized into 3 groups representing different timings to initiate the chemotherapy; less than 2 weeks (group 1), 3 to 4 weeks (group 2), and more than 5 weeks (group 3). The overall survival rate (OS) and the relapse-free survival rate (RFS) were analyzed to evaluate the effectiveness of adjuvant chemotherapy. Results The 5-year OSs of the patients were 73.7% in group 1, 67.0% in group 2, and 55.2% in group 3. The 5-year RFSs of the patients were 48.8% in group 1, 64.7% in group 2, and 57.1% in group 3. There were no significant differences in either the OS or the RFS (P = 0.200, P = 0.405). Conclusion Starting chemotherapy earlier than 6 weeks after surgery does not show any significant difference. Thus, although adjuvant chemotherapy should preferably begin within 6 weeks, the starting date should not necessarily be hastened, and the patients general condition should be taken into consideration.

Psychological attitude to self-appraisal of stoma patients: prospective observation of stoma duration effect to self-appraisal

Purpose In recent years, many psychological problems in patients with stomas have been addressed in a number of studies. But there are only a few studies that use objective measures to take into account self-appraisal by patients with permanent or temporary stomas. The aim of this study is to compare the psychological attitude of patients with permanent and temporary stomas and to determine the most appropriate psychological supportive care. Methods Sixty-five patients, who received a stoma between January 2009 and March 2012, were classified into two groups with either permanent or temporary stomas and were observed prospectively. We developed a questionnaire with the aid of a psychiatrist to analyze the grade of psychological attitude of self-appraisal of patients. The questionnaire was categorized into three parts; body image scale, self-esteem scale, and depression scale. Patients responded to the questionnaire 4 weeks after the operation and the answers of each group were compared. Results Out of 65 patients, 42 received temporary stomas and 23 received permanent stomas. There was no significant mean difference between permanent and temporary stoma patients in the body image scale, the self-esteem scale, and the depression scale. However, patients with a permanent stoma tended to have a worse body image and lower self-esteem on some specific items within the questionnaires. Conclusion Patients with stomas have negative attitudes toward themselves and some meaningful differences were found between different types of stoma applied. Surgeons should be concerned about postoperative psychological support for patients with stomas.

Clinical Applications of Radio-Frequency Ablation in Liver Metastasis of Colorectal Cancer

Purpose The aim of this study is to evaluate long-term survival and prognostic factors for radio-frequency ablation (RFA) in colorectal liver metastases. Methods We retrospectively reviewed 35 colorectal liver metastases patients who underwent RFA between 2004 and 2008. We analyzed survival after RFA and prognostic factors for survival. Results Of the 35 patients, 23 patients were male and 12 were female. Their mean age was 62.40 ± 12.52 years. Mean overall survival was 38.8 ± 4.6 months, and mean progression free survival was 19.9 ± 3.4 months. Three- and 5-year overall survival rates were 42.7 ± 0.1% and 26.0 ± 0.1%, respectively. Three- and 5-year progression-free survival rates were 19.6 ± 0.1% and 4.9 ± 0.04%, respectively. Overall survival and progression-free survival were significantly improved in male and in patients with carcinoembryonic antigen (CEA) ≤ 100 ng/mL, carbohydrate antigen (CA) 19-9 ≤ 100 ng/mL, absence of extrahepatic disease, and a unilobar hepatic lesion. In addition, progression-free survival was improved in patients with a solitary hepatic lesion. On the multivariate analysis, significant survival factors were the absence of extrahepatic disease and the presence of a unilobar hepatic lesion. Conclusion RFA for colorectal liver metastases is an effective treatment option in male patients and in patients with CEA or CA19-9 ≤ 100, absence of extrahepatic disease, a solitary hepatic lesion, and a unilobar hepatic lesion.

Oncologic outcomes in rectal cancer with close distal resection margins: a retrospective analysis.

Purpose The assurance of a negative resection margin is significant in rectal cancer as it indicates a reduced risk of local recurrence; thus, sufficient length of the resection margin is strongly required. The purpose of this study was to analyze the relationship between the length of the distal resection margin (DRM) and local recurrence or survival rate and to evaluate the possibility of performing sphincter-conserving surgery. Methods The medical records of 218 rectal cancer patients were analyzed. Patients were classified into three groups according to the length of the DRM as follows: group 1, DRM < 1 cm; group 2, 1 cm ≤ DRM ≤ 2 cm; and group 3, DRM > 2 cm. Results Of 218 patients enrolled, 81 were in group 1, 66 in group 2, and 71 in group 3. The 5-year survival rates were 78.2%, 78.2%, and 76.8% for groups 1, 2, and 3, respectively, and there were no statistically significant differences in survival (P = 0.913). Local recurrence was found in 2 patients in group 1, 1 patient in group 2, and 1 patient in group 3; there were no statistically significant differences in local recurrence (P = 0.908). Conclusion A DRM of < 1 cm did not impair the oncologic outcomes of rectal cancer patients. Our results indicated that surgeons should keep in mind to consider the option of sphincter-conserving surgery with adjuvant chemoradiotherapy even in very low rectal cancer.