LINC00665 Facilitates the Malignant Processes of Osteosarcoma by Increasing the RAP1B Expression via Sponging miR-708 and miR-142-5p

Osteosarcoma (OS) is a kind of fatal primary bone tumors in adolescents and young adults. Long noncoding RNAs (lncRNAs) are a group of noncoding RNAs which occupy a part of the latest hot topics. We aimed to investigate the roles of lncRNA LINC00665 in OS in this study. In this study, we found that LINC00665 was highly expressed in OS tissues and cell lines, and its high expression was associated with malignant feature and poor prognosis of OS. In OS cells, LINC00665 could facilitate the proliferation, migration, and invasion to play an oncogenic role. Mechanistically, LINC00665 served as a sponge for miR-708 and miR-142-5p and positively mediated the expression of their target RAP1B. Finally, we confirmed that LINC00665 exercised its biological functions by mediating RAP1B. In conclusion, LINC00665 is overexpressed in OS and facilitates the malignant processes of OS cells by increasing the RAP1B expression via sponging miR-708 and miR-142-5p.

RARE-18. CLINICAL EXPERIENCE OF DABRAFENIB IN COMBINATION WITH TRAMETINIB TREATMENT FOR ANAPLASTIC PXA CASES

Anaplastic PXA is classed as grade III tumor because of its aggressive behavior in 2016 WHO classification. Typical treatment of PXA is gross total resection followed by radiotherapy and cytotoxic chemotherapy at recurrence. Despite aggressive behavior of anaplastic PXA, there is some evidence for the use of BRAF inhibitors in BRAF V600 mutant PXA. We report two cases of successful treatment with BRAF-MEK inhibitor combination therapy (dabrafenib plus trametinib). A 19 year-old man initially diagnosed as PXA for rt temporal tumor. Subtotal removal and following 30Gy radiation was performed. After eight years, the recurrent tumor was removed subtotally and diagnosed as anaplastic PXA. Residual tumor and distant metastasis region were completely disappeared by Dabrafenib-Trametinib therapy. Tumor was diagnosed as BRAF V600 mutant and TERT wt. A 30 year-old female initially diagnosed as PXA for rt temporal cystic tumor. She was treated with subtotal removal followed by stereotactic radiosurgery. Instead of Gd-total removal, tumor recurred six times. Chemotherapy with alkyl-agent did not respond. Tumor at first surgery was diagnosed as grade II PXA. Tissues collected after SRS showed malignant feature and diagnosed as anaplastic PXA. All five specimens showed BRAF V600 mutation and additional TERT mutation was confirmed after SRS treatment. She showed paraparesis because of thoracic metastases then Dabrafenib-Trametinib therapy was started. Thoracic tumor showed PR and no remarkable recurrence in intracranial region for more than eight months, so far. BRAF and MEK inhibitor combination treatment are thought to have potential for BRAF V600 mutant NSCLC and melanoma. Anaplastic PXA with BRAF V600 mutation could be another target for the treatment.

Radiologic Findings of a Rare Subtype of Invasive Breast Cancer with Poor Prognosis: Metaplastic Carcinoma of the Breast

Background and Objectives: The purpose of this study was to evaluate the mammographic, sonographic and MRI findings of metaplastic breast carcinoma. Methods: In this retrospective review study, we analyzed the medical files of 9600 patients who were treated for invasive breast cancers. Clinical information, histopathologic and radiologic findings of 65 patients were included in this study. All existing radiologic images and medical reports were reviewed retrospectively. Thirty-three patients had MG, 58 patients had US and 7 patients had MRI imaging results. Results: Mammographically, the most frequent presentations of MPBC were round shape, microlobulated margin and high density masses. Calcifications with or without masses were not a frequent finding. The most common sonographic findings were round shape, partially indistinct angular margin, hypoechoic and heterogeneous echo patterns and no posterior feature masses. All lesions were presented as masses rather than non-mass enhancements on magnetic resonance imaging. Features of masses had more malignant feature on MRI than other modalities in all 7 patients. Conclusion: Metaplastic breast carcinoma is one of the rarest poorly differentiated invasive breast carcinomas. Interestingly, these aggressive tumors demonstrate benign or moderately malign features on imaging methods. This appearance of MPBC can cause it to be misdiagnosed as a benign breast lesion especially in young women. MPBC should be kept in mind in the differential diagnosis of large palpable breast masses. Therefore, follow-up at short intervals and/or multimodality imaging studies which include breast MRI are important for the diagnosis of MPBC.

Usefulness of circulating tumor cell detection for the diagnosis of malignant pancreatic head tumors: A pilot study.

235 Background: Pancreatic adenocarcinomas account for 90% of pancreatic malignancies. It is often diagnosed at an unresectable stage (at a metastatic and / or at a locoregional invasion stage). Histological diagnosis is mandatory to establish palliative chemotherapy. Endoscopic ultrasound-guided fine needle aspiration (EUGA) of pancreatic tumors is a difficult gesture, not without risk. Furthermore, it frequently provides pauci-cellular, hemorrhagic or necrotic material unsuitable for precise histologic diagnosis. Techniques for detecting circulating tumor cells (CTC) have been recently developed to highlight the presence of malignant cells circulating in peripheral blood. Screencells technology is based on the separation of CTCs from other circulating cells by blood filtration through a polycarbonate membrane with 7m pores. The aims of this pilot study were 1) to compare the results of detections CTC to EUGA, 2) to assess the feasibility and the contribution of this innovative technique in the care of a limited series of patients. Methods: A sample of peripheral venous blood was performed in 15 patients with a suspicious CT scan of a pancreatic head tumoral lesion, before the completion of an EUGA. 4 ml of blood were filtered using ScreencellsCyto columns. After Giemsa staining, a pathologist analyzed each filter. Cells visualized on the filter under light microscopy were considered as tumoral if they met the following morphological criteria: anisocytosis, anisokaryosis, nuclear diameter>7m, nuclear membrane irregularitie, large nucleolus. Results: The malignant feature of the pancreatic lesion could be histologically assessed after liver biopsy for two patients. EUGA showed malignancy in 10 cases. CTC presence was identified in 7 patients with tumoral histological diagnosis. Conclusions: This study demonstrates the feasibility of CTC detection in patients with pancreatic head tumor. The identification of CTCs could facilitate patient care, thus avoiding difficult and potentially dangerous EUGA. A prospective trial is needed to confirm the positive predictive value of this biomarker and to evaluate its contribution in the diagnosis procedure of such tumors.