Autophagy Inhibition with Monensin Enhances Cell Cycle Arrest and Apoptosis Induced by mTOR or Epidermal Growth Factor Receptor Inhibitors in Lung Cancer Cells / 결핵및호흡기질환

BACKGROUND: In cancer cells, autophagy is generally induced as a pro-survival mechanism in response to treatment-associated genotoxic and metabolic stress. Thus, concurrent autophagy inhibition can be expected to have a synergistic effect with chemotherapy on cancer cell death. Monensin, a polyether antibiotic, is known as an autophagy inhibitor, which interferes with the fusion of autophagosome and lysosome. There have been a few reports of its effect in combination with anticancer drugs. We performed this study to investigate whether erlotinib, an epidermal growth factor receptor inhibitor, or rapamycin, an mammalian target of rapamycin (mTOR) inhibitor, is effective in combination therapy with monensin in non-small cell lung cancer cells. METHODS: NCI-H1299 cells were treated with rapamycin or erlotinib, with or without monensin pretreatment, and then subjected to growth inhibition assay, apoptosis analysis by flow cytometry, and cell cycle analysis on the basis of the DNA contents histogram. Finally, a Western blot analysis was done to examine the changes of proteins related to apoptosis and cell cycle control. RESULTS: Monensin synergistically increases growth inhibition and apoptosis induced by rapamycin or erlotinib. The number of cells in the sub-G1 phase increases noticeably after the combination treatment. Increase of proapoptotic proteins, including bax, cleaved caspase 3, and cleaved poly(ADP-ribose) polymerase, and decrease of anti-apoptotic proteins, bcl-2 and bcl-xL, are augmented by the combination treatment with monensin. The promoters of cell cycle progression, notch3 and skp2, decrease and p21, a cyclin-dependent kinase inhibitor, accumulates within the cell during this process. CONCLUSION: Our findings suggest that concurrent autophagy inhibition could have a role in lung cancer treatment.

Dual Inhibition of PI3K/Akt/mTOR Pathway and Role of Autophagy in Non-Small Cell Lung Cancer Cells / 결핵및호흡기질환

BACKGROUND: The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling axis has emerged as a novel target for cancer therapy. Agents that inhibit this pathway are currently under development for lung cancer treatment. In the present study, we have tested whether dual inhibition of PI3K/Akt/mTOR signaling can lead to enahnced antitumor effects. We have also examined the role of autophagy during this process. METHODS: We analyzed the combination effect of the mTOR inhibitor, temsirolimus, and the Akt inhibitor, GSK690693, on the survival of NCI-H460 and A549 non-small cell lung cancer cells. Cell proliferation was determined by MTT assay and apoptosis induction was evaluated by flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Autophagy induction was also evaluated by acridine orange staining. Changes of apoptosis or autophagy-related proteins were evaluated by western blot analysis. RESULTS: Combination treatment with temsirolimus and GSK690693 caused synergistically increased cell death in NCI-H460 and A549 cells. This was attributable to increased induction of apoptosis. Caspase 3 activation and poly(ADP-ribose) polymerase cleavage accompanied these findings. Autophagy also increased and inhibition of autophagy resulted in increased cell death, suggesting its cytoprotective role during this process. CONCLUSION: Taken together, our results suggest that the combination of temsirolimus and GSK690693 could be a novel strategy for lung cancer therapy. Inhibition of autophagy could also be a promising method of enhancing the combination effect of these drugs.

Unusual Radiologic Findings and Pathologic Growth Patterns on Choroid Plexus Papillomas

OBJECTIVE: Choroid plexus papillomas (CPPs) are generally regarded as benign tumors with typical radiologic and pathologic findings. However, they sometimes have unusual findings. We have analyzed radiologic findings and pathologic growth patterns on CPPs. METHODS: The study group included 5 male and 5 female patients (age range, 3 months to 58 years : median, 29 years). The study group included 3 pediatric and 7 adult patients. All patients underwent surgery; 9 patients had a gross total resection and 1 patient had a subtotal resection. We analyzed the radiologic findings (location, size, mottle-like appearance, enhancement, calcifications, and hydrocephalus) and pathologic growth patterns (typical papillary, papillary and solid, and papillary and tubular). RESULTS: The median follow-up duration was 21.3 months (range, 4-47.8 months). There were no recurrences after initial treatment. All patients had benign CPPs. Pediatric CPPs were 3.2 cm masses (range, 2.7-4 cm) with homogeneous enhancement and a mottle-like appearance, which pathologically showed the papillary growth pattern. Hydrocephalus was present in all pediatric patients. Postoperatively, subdural hygroma had occurred in two patients. In adults, CPPs were located in the fourth ventricle in 6 patients and suprasellar area in 1 patient. The size varied from 0.5-4.2 cm. Hydrocephalus and calcifications occurred in 3 and 4 patients, respectively. Three patients showed the heterogeneous enhancement without a mottle-like appearance and pathologically showed combined papillary and solid growth in 2 patients and papillary and tubular growth in one. Postoperatively, two patients with large masses had injuries of the brainstem and underwent shunt procedures for aggravation of hydrocephalus. CONCLUSION: CPPs may show unusual radiologic findings, which preoperatively give the difficulty to be differentiated from other tumors. CPPs with unusual radiologic findings showed the combined pathologic growth patterns.

Differences in Expression of VEGF-A, VEGFR-1, VEGFR-2 and Microvessel Density in Colorectal Cancer with Liver Metastasis

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignant neoplasms and is a leading cause of mortality worldwide. Metastasis to the liver is a frequent event in patients with CRC. An essential step in the metastatic cascade is angiogenesis. METHODS: This study included 45 patients who underwent a partial colectomy with hepatic resection for CRC with hepatic metastases. Immunohistochemistry was performed using vascular endothelial growth factor (VEGF)-A, VEGF receptor (VEGFR)-1, VEGFR-2, and CD34 antibodies to examine the relationship between CRC with liver metastases and angiogenesis. RESULTS: CRC showed significantly stronger expression of VEGF-A, VEGFR-1, and VEGFR-2 than liver metastases (p < 0.05). Microvessel density was also higher in CRC than in liver metastases (p < 0.05). CONCLUSIONS: Compared with previous studies, we found a higher expression of VEGF-A, VEGFR-1, VEGFR-2, and microvessel density in CRC than in liver metastases, which could be ascribed to a difference in vessel distribution and blood supply in each organ. Given its profuse blood supply and distinct cell populations, the liver might provide a rich milieu for tumor cell growth with less expression of angiogenesis-inducing agents.

Homocysteine as a Risk Factor for Development of Microalbuminuria in Type 2 Diabetes / 당뇨병

BACKGROUND: Kidney function is critical in homocysteine clearance, and plasma homocysteine level is frequently increased in patients with renal failure. On the other hand, recent studies in animals have shown that hyperhomocysteinemia induces renal injury. In this study, we determined whether hyperhomocysteinemia can be a risk factor for the development of microalbuminuria in patients with type 2 diabetes. METHODS: A nested case-control study. Of 887 patients with type 2 diabetes who did not have microalbuminuria at baseline, 76 developed microalbuminuria during follow-up (mean, 36.0 +/- 11.7 months; range, 18 to 76 months). The control group consisted of 152 age- and sex-matched subjects who did not develop microalbuminuria. Baseline plasma homocysteine concentrations were measured in stored samples. RESULTS: Baseline plasma homocysteine concentrations and mean HbA1C levels during follow-up were significantly higher in patients who developed microalbuminuria than in those who remained normoalbuminuric. Multivariate logistic regression analysis showed that baseline plasma homocysteine level and mean HbA1C were independent predictors of microalbuminuria in type 2 diabetes. CONCLUSION: Hyperhomocysteinemia was associated with increased risk of microalbuminuria in patients with type 2 diabetes supporting the concept that hyperhomocysteinemia has an etiologic role in the pathogenesis of diabetic nephropathy.

Exuberant Smooth Muscle Cells in Fibroadenoma of the Breast: A Case Report

Smooth muscle cell metaplasia is an extremely rare form of stromal differentiation in fibroadenomas. We describe a case of fibroadenoma with exuberant smooth muscle cells in a 72-year-old woman. The mass was located in the upper central portion of the left breast. It was well circumscribed and its greatest dimension was 3 cm. Histologically, the glandular elements resembled the appearance of fibroadenoma, but the stromal elements were composed of spindle cell bundles with abundant eosinophilic cytoplasm and elongated cigar-shaped nuclei. Neither mitotic activity nor cellular atypia was seen. The stromal cells were immunohistochemically positive for smooth muscle actin, calponin, desmin, and estrogen receptor-beta, but negative for CD34, S-100 protein, p63, CD10, estrogen receptor-alpha, progesterone receptor and cytokeratin. These results proved that the stromal cells showed features of smooth muscle cells.

HPV Genotyping in Squamous Cell Carcinoma of Upper Aerodigestive Tract

BACKGROUND: Smoking and alcohol consumption are the main risk factors for squamous cell carcinoma of the upper aerodigestive tract (SCCUAT). However, human papillomavirus (HPV) has been etiologically linked with tonsillar squamous cell carcinoma (TSCC). Therefore, we investigated the etiologic role of HPV in the context of SCCUAT in Korea. METHODS: Archival paraffin block samples from 136 cases previously diagnosed as SCCUAT were randomly selected. A commercial HPV DNA chip was used for HPV genotyping. RESULTS: One hundred and seventeen cases were available after checking beta-globin (47 cases of tonsil and 70 of non-tonsil). A HPV-positive result (HPV 16 and 18) occurred in 13 cases of SCCUAT, and 12 cases were tonsil (25.5%, 12/47). Among the 12 HPV-positive patients with TSCC, nine were non-smokers and non-drinkers. Most HPV-negative patients with TSCC had a history of alcohol drinking and smoking (32/35, 91.4%). HPV infection status was not significantly associated with histological grade, clinical stage, or survival in patients with TSCC. CONCLUSIONS: HPV infection was significantly higher in patients with TSCC among those with SCCUAT. HPV may be independent risk factor in development of TSCC, such as smoking and alcohol drinking.

Juvenile Dermatomyositis Diagnosed by (99m)Tc-HDP Three-phase Bone Scintigraphy / 핵의학분자영상

Juvenile dermatomyositis is a common inflammatory muscle disease of childhood, characterized by weakness in proximal muscles and specific skin rash. In case of juvenile dermatomyositis without characteristic clinical features, non-invasive imaging tools such as (99m)Tc-HDP three-phase bone scan are very helpful in diagnostic workup of myopathies. We report a case of 13-year old female with juvenile dermatomyositis, in which (99m)Tc-HDP three-phase bone scan was useful in diagnosis and assessing therapy response.