We present a cohort of 41 patients with osimertinib resistance biopsies, including two with an acquired CCDC6-RET fusion. While RET fusions have been identified in resistant EGFR-mutant NSCLC, their role in acquired resistance to EGFR inhibitors is not well described. To assess the biological implications of RET fusions in an EGFR-mutant cancer, we expressed CCDC6-RET in PC9 (EGFR del19) and MGH134 (EGFR L858R/T790M) cells and found that CCDC6-RET was sufficient to confer resistance to EGFR-TKIs. The selective RET inhibitors BLU-667 or cabozantinib resensitized CCDC6-RET-expressing cells to EGFR inhibition. Finally, we treated two patients with EGFR-mutant NSCLC and RET-mediated resistance with osimertinib and BLU-667. The combination was well-tolerated and led to rapid radiographic response in both patients. This study provides proof-of-concept that RET fusions can mediate acquired resistance to EGFR TKIs and that combined EGFR and RET inhibition with osimertinib/BLU-667 may be a well-tolerated and effective treatment strategy for such patients.

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Non-coding RNA (ncRNA) plays a regulatory role in a variety of cellular activities. And long non-coding RNA (lncRNA) is one of the important kinds of ncRNA. Previous studies have shown that various lncRNAs are involved in the progression of cancer. LncRNA plasmacytoma variant translocation 1 (PVT1) is a newly discovered oncogenic factor that has been confirmed to be overexpressed in many cancer cells. Moreover, the role of PVT1 in cancer development is closely linked to microRNAs (miRNAs). PVT1 can act as a “sponge” for miRNAs to inhibit their activities, thereby affecting proliferation, invasion, and angiogenesis of cancer. In addition, PVT1 itself can be spliced and processed into several miRNAs such as miR-1204 and miR-1207, which can also regulate the development of cancer. This review summarizes various pathways through which PVT1 regulates the progression of cancer via miRNAs. We also propose additional regulatory mechanisms of PVT1 and their potential clinical applications.

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Peripheral T-cell lymphoma (PTCL) forms a morphologically heterogeneous group of non-Hodgkin's lymphomas (NHL) with distinct immunophenotypes of mature T cells. Progress has been slow in defining specific clinicopathological entities to this particular group of NHL. In order to elucidate the specific characteristics of PTCL, a direct comparison of PTCL with a group of diffuse B-cell lymphomas (DBCL) was performed. Between June 1983 and December 1987, we studied 114 adults with NHL, using a battery of immunophenotyping markers. Adult T-cell leukemia/lymphoma, lymphoblastic lymphoma, mycosis fungoides/Sézary syndrome, follicular lymphoma, well-differentiated lymphocytic lymphoma, and true histiocytic lymphoma were excluded from this study since these are distinct clinicopathologic entities with well-recognized immunophenotypes. Of the remaining 75 patients, 70 who had adequate clinical information were analyzed, and of these, 34 were PTCL and 36 were DBCL. Classified according to the National Cancer Institute (NCI) Working Formulation (WF), 68% of PTCL and 31% of DBCL were high-grade lymphomas. Clinical and laboratory features were similar, except PTCL had a characteristic skin involvement and tended to present in more advanced stages with more constitutional symptoms. Induction chemotherapy was homogeneous in both groups, and complete remission rates were 62% for PTCL and 67% for DBCL. Patients with DBCL had a better overall survival than patients with PTCL, but the survival benefit disappeared after patients were stratified according to intermediate- or high-grade lymphoma. A subgroup of PTCL patients who had received less intensive induction chemotherapy was found to have a very unfavorable outcome. We conclude that (1) PTCL follows the general grading concept proposed in WF classification; (2) within a given intermediate or high grade, PTCL and DBCL respond comparably to treatment; (3) the intensity of induction chemotherapy has a crucial impact on the outcome of PTCL patients; and (4) with a few exceptions, the clinical and laboratory features of PTCL and DBCL are comparable.

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An off-line 2D high-speed counter-current chromatography technique in preparative scale has been successfully applied to separate and purify the main compounds from the ethyl acetate extract of Desmodium styracifolium. A two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water at an optimized volume ratio of 1:2:1:2 v/v/v/v was used. Conventional high-speed counter-current chromatography was used as the first dimension, and the upper phase of the solvent system was used as the stationary phase in the head-to-tail elution mode at a flow rate of 2.0 mL/min and a rotation speed of 900 rpm. Recycling high-speed counter-current chromatography served as the second dimension to separate an impure fraction of the first dimension. A total of four well-separated substances including vanillic acid (1), β-sitosterol (2), formononetin (3), and aromadendrin (4) were obtained, and their purities and structures were identified by HPLC-MS and (1) H NMR spectroscopy. The results illustrated that off-line 2D high-speed counter-current chromatography is an effective way to isolate compounds in complex samples.

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