No abstract

A novel EGFR-tyrosine kinase inhibitor (TKI), osimertinib, has marked efficacy in patients with EGFR-mutated lung cancer. However, some patients show intrinsic resistance and an insufficient response to osimertinib. This study showed that osimertinib stimulated AXL by inhibiting a negative feedback loop. Activated AXL was associated with EGFR and HER3 in maintaining cell survival and inducing the emergence of cells tolerant to osimertinib. AXL inhibition reduced the viability of EGFR-mutated lung cancer cells overexpressing AXL that were exposed to osimertinib. The addition of an AXL inhibitor during either the initial or tolerant phases reduced tumor size and delayed tumor re-growth compared to osimertinib alone. AXL was highly expressed in clinical specimens of EGFR-mutated lung cancers and its high expression was associated with a low response rate to EGFR-TKI. These results indicated pivotal roles for AXL and its inhibition in the intrinsic resistance to osimertinib and the emergence of osimertinib-tolerant cells.

Both treatments were generally well-tolerated. Clinically significant AEs were observed in 35.1% of patients in the GC arm and 29.9% in the GS arm.Conclusions: GS, which does not require hydration, should be considered a new, convenient standard of care option for patients with advanced/recurrent BTC.Clinical Trial number: This trial has been registered with the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/index. htm), number UMIN000010667.

Primary central nervous system lymphoma (PCNSL) is a rare malignancy confined to the central nervous system (CNS), and majority of PCNSL is pathologically classified as diffuse large B-cell lymphoma (DLBCL). We have now performed whole-exome sequencing for 41 tumor tissues of DLBCL-type PCNSL and paired normal specimens and also RNA-sequencing for 30 tumors, revealing a very high frequency of nonsynonymous somatic mutations in PIM1 (100 %), BTG2 (92.7 %), and MYD88 (85.4 %). Many genes in the NF-κB pathway are concurrently mutated within the same tumors. Further, focal deletion or somatic mutations in the HLA genes are associated with poor prognosis. Copy number amplification and overexpression of genes at chromosome 7q35 were both found to predict short progression-free survival as well. Oncogenic mutations in GRB2 were also detected, the effects of which in cultured cells were attenuated by inhibitors of the downstream kinases MAP2K1 and MAP2K2. Individuals with tumors positive for MYD88 mutations also harbored the same mutations at a low frequency in peripheral blood mononuclear cells, suggesting that MYD88 mutation-positive precancerous cells originate outside of the CNS and develop into lymphoma after additional genetic hits that confer adaptation to the CNS environment.

Members of the RAS superfamily of small guanosine triphosphatases (GTPases) transition between GDP-bound, inactive and GTPbound, active states and thereby function as binary switches in the regulation of various cellular activities. Whereas HRAS, NRAS, and KRAS frequently acquire transforming missense mutations in human cancer, little is known of the oncogenic roles of other small GTPases, including Ras-related C3 botulinum toxin substrate (RAC) proteins. We show that the human sarcoma cell line HT1080 harbors both NRAS(Q61K) and RAC1(N92I) mutant proteins. Whereas both of these mutants were able to transform fibroblasts, knockdown experiments indicated that RAC1(N92I) may be the essential growth driver for this cell line. Screening for RAC1, RAC2, or RAC3 mutations in cell lines and public databases identified several missense mutations for RAC1 and RAC2, with some of the mutant proteins, including RAC1(P29S), RAC1(C157Y), RAC2(P29L), and RAC2(P29Q), being found to be activated and transforming. P29S, N92I, and C157Y mutants of RAC1 were shown to exist preferentially in the GTP-bound state as a result of a rapid transition from the GDP-bound state, rather than as a result of a reduced intrinsic GTPase activity. Activating mutations of RAC GTPases were thus found in a wide variety of human cancers at a low frequency; however, given their marked transforming ability, the mutant proteins are potential targets for the development of new therapeutic agents.oncogene | resequencing

The clinicopathological characteristics and outcome of splenic flexure cancer after surgery have yet to be fully elucidated. The aim of the current study was, therefore, to establish predictive factors related to splenic flexure cancer and outcome after surgery. We compared the clinicopathological characteristics and outcome of 34 patients with splenic flexure cancers (which represents 3.7% of the total number of colon cancers in our series) with those of 418 patients with right colon and 475 patients with left colon cancers by univariate and multivariate analyses, using logistic regression analysis and Cox's proportional hazards model. Splenic flexure cancers had a high risk of obstruction (26.5% of patients), and had a more advanced stage and lower cure rate than left colon cancers. Logistic regression analysis revealed that two independent factors, colonic obstruction and the presence of distant metastases, were related to the splenic flexure tumor site. Splenic flexure cancer patients had a poorer outcome than those with left colon cancer (P = 0.0361). However, there was no difference in survival between patients with splenic flexure, those with right colon cancer and those with left colon cancer who underwent curative surgery. Cox's regression analysis revealed that neither the site of splenic flexure nor colonic obstruction was an independent prognostic factor. In conclusion, splenic flexure cancer is characterized by a high risk of obstruction and the presence of distant metastases. However, after curative resection, splenic flexure cancer has a similar outcome to colon cancer at other sites. In addition, neither the splenic flexure site nor colonic obstruction had an independent influence on patient survival after surgery.

To clarify the relationship between morphological measurements of hepatic volume by computed tomography (CT-vol) and functional volume (RI-vol) by technetium-99m galactosyl human serum albumin (99mTc-GSA) scintigraphy, and its clinical significance, we examined 16 patients with a background liver status of either normal liver function (n=4), chronic hepatitis or cirrhosis (n=7), or obstructive jaundice (n=5). In five patients who underwent preoperative portal vein embolization (PVE), volumetric measurement was performed 2 weeks after PVE. The mean values of CT-vol and RI-vol of the right lobe were 692+/-147 cm3 (66.1+/-10.7%) and 668+/-159 cm3 (67.8+/-13.2%), respectively, and those of the left lobe were 329+/-138 cm3 (33.9+/-10.6%) and 328+/- 170 cm3 (32.2+/-13.2%), respectively. There were no significant differences in the volume measurements between the two volumetric techniques. Correlations between CT-vol and RI-vol in the right and left lobes were positive and significant (r=0.912 and 0.903, respectively; both P's<0.001). The mean values of post-PVE CT-vol and RI-vol of the right lobe in five patients were significantly different (628+/-149 and 456+/-211 cm3, respectively; P=0.033). However, the mean values of post-PVE CT-vol and RI-vol of the left lobe were not different (496+/-124 and 483+/-129 cm3, respectively). We propose that volumetric measurement by 99mTc-GSA scintigraphy is useful for detecting changes in functional volume of individual lobes of the liver and is a more dynamic method compared with detection of morphological changes by CT scan.

Adjuvant PDT is a safe and useful option for a better survival benefit in patients with BDC undergoing surgical resection.