Downregulation of chemoresistance by claudin-14 silencing in human colorectal cancer cells.

An exceptional expression of claudins (CLDNs), tight junction (TJ) proteins, is observed in various solid cancer tissues. However, the pathophysiological roles of CLDNs have not been clarified in detail. CLDN14 is highly expressed in human colorectal cancer (CRC) tissues and cultured cancer epithelial cells. We found CLDN14 silencing decreased cell viability without affecting spheroid size in the three-dimensional (3D) spheroid model of DLD-1 cells derived from human CRC. Mitochondria activity and oxidative stress level were reduced by CLDN14 silencing. Furthermore, CLDN14 silencing decreased the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and its target antioxidative genes. CLDN14 was colocalized with ZO-1, a scaffolding protein in the TJ. CLDN14 silencing induced the disruption of TJ barrier such as the reduction of transepithelial electrical resistance and elevation of fluxes of small molecules including glucose in two-dimensional (2D) cultured model,. The depletion of glucose induced the elevation of ROS generation, mitochondria activity, and Nrf2 expression. These results suggest that CLDN14 increases Nrf2 expression in spheroids mediated via the formation of paracellular barrier to glucose. The cytotoxicities of doxorubicin, an anthracycline anticancer drug, and oxaliplatin, a platinum-based agent, were augmented by an Nrf2 activator in 2D cultured cells. The anticancer drug-induced toxicity was enhanced by CLDN14 silencing in 3D spheroids. We suggest that CLDN14 may potentiate chemoresistance mediated by the suppression of paracellular glucose permeability and activation of the Nrf2 signaling pathway in CRC cells.

[Multiple Pulmonary Metastases Seven Years After Transurethral Bladder Tumor Resection for Non-muscle Invasion Bladder Cancer:Report of a Case].

A 64-year-old man was admitted because of multiple pulmonary nodules in right upper lobe on chest computed tomography (CT). He had non-muscle invasion bladder cancer resected by transurethral bladder tumor resection seven years ago. Partial resections of the right upper lobe were carried out at the video assisted thracoscopic surgery (VATS) for diagnostic purposes. The postoperative pathological examination revealed featuraes of pulmonary metastasis of bladder cancer. Although chemotherapy after biopsy was performed, a residual tumor in right S3 has grown. Partial resection of residual tumor was carried out thracoscopically and the tumor was diagnosed as metastasis of bladder cancer. He has been without recurrence for 1 year after the operation.

[Adenocarcinoma with Aplastic Anemia as an Immune-related Adverse Event Caused by Pembrolizumab: Report of a Case].

A 74-year-old man was found a left completely atelectasis on chest X-ray. He had undergone left lower lobe resection because of an adenocarcinoma at the age of 58. Bronchoscopy revealed a tumor near the left upper lobe branch entry that obstructed the lumen, and a biopsy confirmed the diagnosis of adenocarcinoma. A left completion pneumonectomy was performed, but #4L and #10 lymph nodes could not be completely resected. Programmed cell death 1-ligand 1( PD-L1) was positive with tumor proportion score (TPS) 15%, so chemotherapy with pembrolizumab+pemetrexed+carboplatin was started about 1.5 months after surgery. Pancytopenia appeared from the seventh course and did not improve after discontinuation of chemotherapy, so we consulted to the hematologist. He was diagnosed as aplastic anemia by bone marrow biopsy. Aplastic anemia was unresponsive to treatment and chemotherapy could not be resumed. He died of exacerbation of lung cancer.

[Lung cancer incidentally detected at the treatment of pneumothorax ; report of two cases].

We report 2 cases of lung cancer incidentally detected following pneumothorax. Case 1:A 40-year-old man complaining of dyspnea was admitted with right pneumothorax. Chest computed tomography (CT) after chest drainage showed a cavitary nodule with pleural indentations in the right lower lobe. It was indicated at surgery that pneumothorax was caused by perforation of the tumor into the pleural cavity. Right lower lobectomy was performed because the pathological diagnosis of the nodule was a large cell carcinoma. The final histopathological diagnosis was stage II A (pT2aN1M0). The patient died of recurrence 14 months after surgery. Case 2:A 47-year-old man who admitted with right pneumothorax was found to have a nodule with pleural indentations closely a bulla at the apex of the right lung by chest CT after chest drainage. Pneumothorax was indicated to be caused by rupture of the bulla at surgery. Right upper lobectomy was performed because the pathological diagnosis of the nodule was a squamous carcinoma. The final histopathological diagnosis was stage I A (pT1bN0M0). The patient is alive at 2 years after the operation without recurrence. Lung cancer detected following pneumothorax which was caused by perforation of the tumor is generally considered to have poor prognosis. Whereas, prognosis of lung cancer incidentally detected following pneumothorax depends on its staging.

Ewing's sarcoma family of tumors originating in the main bronchus.

Ewing's sarcoma family tumors (ESFT), which include Ewing's sarcoma and primitive neuroectodermal tumors (PNET), have been reported to originate in a variety of sites, mostly in the extremities. Previous reports have shown ESFT originating in the thoracic region, such as chest wall and peripheral lung. We herein report the first case of the ESFT that originated in the main bronchus. Endobronchial snare resection was followed by five courses of chemotherapy (VDC-IE; including vincristine, doxorubicin, cyclophosphamide, ifosfamide and etoposide) and sequential radiation. After the treatment, the patient's condition has improved, and he has remained disease-free for the past year.

MT1-MMP plays an important role in an invasive activity of malignant pleural mesothelioma cell.

Malignant pleural mesothelioma (MPM) has a poor prognosis and is a treatment resistant tumor, which is increasing in frequency throughout the world. The poor prognosis is due to the aggressive local invasiveness rather than distant metastasis. In this study, we established a cell line of malignant mesothelioma from a clinical specimen and assessed the relationship between the expression of MT1-MMP and the invasion ability of that line, as well as the cultured cells of several other lines, using the simple method that we created previously. We established a cell line from a clinical specimen from a patient with malignant mesothelioma. We assessed the invasive activities of MPM cells in an easy-to-prepare double-layered collagen gel hemisphere (DL-CGH) system that enabled us to visualize cell movements during invasion. To assess the role of MT1-MMP in the invasive activity of MPM cells, we knocked down its expression by RNA interference (RNAi). The invasion assay with DL-CGH revealed that a high expression of MT1-MMP in MPM cells was associated with aggressive invasive activity. The RNAi of MT1-MMP indicated that the expression of MT1-MMP might have a crucial role in the invasiveness of MPM cells. The MT1-MMP expression in MPM cells is related to their capacity for locally aggressive spreading into the pleura and the surrounding tissues, and MT1-MMP should be a suitable molecular target for the suppression of the invasiveness of MPM.

Chemosensitivity of lung cancer: Differences between the primary lesion and lymph node metastasis.

In this study, chemosensitivity tests were performed on both primary lesions (PLs) and lymph node metastases (LMs) from surgically resected non-small cell lung cancer (NSCLC). Differences between the results obtained were evaluated. Operative specimens were obtained from 13 patients with NSCLC [6 with squamous cell carcinoma (SQ) and 7 with adenocarcinoma (AD)] whose lymph nodes were confirmed to be positive for metastasis. Both the PL and LM from the same patient were examined immediately after resection. The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) was used as the chemosensitivity test against six anticancer drugs [5-fluorouracil (5-FU), cisplatin, gemcitabine, docetaxel, vinorelbine and SN-38 (an active metabolite of irinotecan)]. When the growth rate, determined by the T/C ratio (T, signal for viable cells in the treated group and C, signal in the control) was less than 50%, the tumor cells were considered to be sensitive to the drug. Only in 4 cases (2 SQ and 2 AD) was the chemosensitivity of the primary lesion identical to that of LM. In the SQ cases, chemosensitivity of the primary lesions to 5-FU tended to be consistent with that of LMs. In contrast, the primary lesions in 4 of the 7 AD cases were negative for chemosensitivity to 5-FU; however, LMs were sensitive. In many cases, the chemosensitivity of the PLs to each anticancer drug differed from that of the LMs. In conclusion, both primary and metastatic tumors should be examined to ensure maximum clinical efficacy of in vitro drug-sensitivity testing for adjuvant chemotherapy after complete resection of n1 and n2 NSCLC.