PurposeHistone deacetylase 5 (HDAC5) is an important protein in neural and cardiac diseases and a potential drug target. However, little is known regarding the specific role of HDAC5 in breast cancer (BC). We aimed to evaluate HDAC5 expression in human breast tumors and to determine the effects of the inhibition of HDAC5 expression in BC cells.Experimental designHDAC5 expression was evaluated in BC patients and was correlated with clinical features and with patient prognosis. Functional experiments were performed using shRNA and the selective HDAC inhibitor LMK-235 for HDAC5 knockdown and inhibition in BC cells. The synergistic effects of LMK-235 with the proteasome inhibitor bortezomib were also examined.ResultsHDAC5 was extensively expressed in human BC tissues, and high HDAC5 expression was associated with an inferior prognosis. Knockdown of HDAC5 inhibited cell proliferation, migration, invasion, and enhanced apoptosis. The HDAC5 inhibitor LMK-235 inhibited cell growth and induced apoptosis, while the inclusion of bortezomib synergistically enhanced the efficacy of LMK-235.ConclusionsOur findings indicate that HDAC5 is a promising prognostic marker and drug target for BC and that the combination of LMK-235 and bortezomib presents a novel therapeutic strategy for BC.

BackgroundIt has been reported that the PI3K/AKT signaling pathway is activated in diffuse large B-cell lymphoma (DLBCL), PI3K constitutive activation plays a crucial role in PI3K/AKT pathway. However, the copy number variations (CNVs) of PI3K subunits on gene level remain unknown in DLBCL. Therefore, the aim of the study is to investigate the CNV of PI3K subunits and their relationship with clinicopathological features exploring the possible mechanism underlying of PI3K activation in DLBCL.MethodsCNV of 12 genes in the PI3K/AKT pathway was detected by NanoString nCounter in 60 de novo DLBCLs and 10 reactive hyperplasia specimens as controls. Meanwhile, immunohistochemistry (IHC) was performed to examine the expression of p110α, p110β, p110γ, p110δ, and pAKT on DLBCL tissue microarrays.ResultsAll PI3K and AKT subunits, except for PIK3R1, had various CNVs in the form of copy number amplifications and copy number losses. Their rates were in the range of 8.3–20.0%. Of them PIK3CA and PIK3CB gene CNVs were significantly associated with decreased overall survival (P = 0.029 and P = 0.019, respectively). IHC showed that the frequency of strong positive expression of p110α, p110β, p110γ, and p110δ were 26.7%, 25.0%, 18.3%, and 25.0% respectively, and they were found to be associated with decreased survival (P = 0.022, P = 0.015, P = 0.015, and P = 0.008, respectively). Expression of p110α was not only significantly associated with CNVs of PIK3CA (P = 0.002) but also positively correlated with strong positive expression of pAKT (P = 0.026).ConclusionsCNV of PIK3CA is highly associated with aberrant p110α protein expression and subsequent activation of PI3K/AKT pathway. CNVs of PIK3CA and PIK3CB, and aberrant protein expression of p110 isoforms are of great important value for predicting inferior prognosis in DLBCL. Frequent CNVs of PI3K/AKT subunits may play an important role in the tumorigenesis of DLBCL.

Purpose: BATF2, a novel IFN-stimulated gene, inhibits tumor cell proliferation, invasion, and migration. The objectives of this study were to determine how BATF2 expression is associated with colorectal cancer progression and patient outcome, to investigate how BATF2 overexpression inhibits hepatocyte growth factor (HGF)/MET signaling, and to elucidate the rationale for combining MET inhibitors with IFN.Experimental Design: BATF2 expression in colorectal cancer tissues was determined and correlated with colorectal cancer patient prognosis. Cultured colorectal cancer cells were used to investigate the effects of BATF2 overexpression on the malignant phenotype of colorectal cancer cells and HGF/MET signaling. Tumor xenograft models were used to validate the effects of BATF2 on colorectal cancer xenograft growth and assess the efficacy of the combination of MET inhibitors with IFNs in colorectal cancer. Results:In colorectal cancer tissues, BATF2 was found to be significantly downregulated, and its expression negatively correlated with MET expression. Decreased BATF2 expression was associated with progression and shorter patient survival in colorectal cancer. BATF2 overexpression promoted apoptosis and inhibited proliferation, migration, and invasion in colorectal cancer cells, as well as dramatically blunted tumor xenograft growth. In addition, MET inhibitors in combination with IFNb produced synergistic cytotoxicity both in vitro and in vivo.Conclusions: Together, these novel findings suggest that BATF2, a tumor suppressor gene, is a potent negative regulator of HGF/MET signaling in colorectal cancer and may serve as a prognostic tumor marker. Furthermore, these results provide a rationale for combining MET inhibitors with IFNs in preclinical trials.

ObjectiveTo detect ROS1 rearrangement using three different assays, including immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and reverse transcription polymerase chain reaction (RT-PCR), and to analyze the clinicopathologic features of ROS1 rearrangement in patients with lung adenocarcinoma.MethodsOne hundred eighty-three consecutive patients with lung adenocarcinoma with operation and follow-up data were analyzed for ROS1 rearrangement by IHC, FISH, and RT-PCR. PCR products of the RT-PCR-positive samples were sequenced for confirmation of the specific fusion partners.ResultsThree of the 183 (1.64%) cases were identified to be positive for ROS1 rearrangement through all three methods. The fusion patterns were CD74 e6-ROS1 e32, CD74 e6-ROS1 e34, and TPM3 e8-ROS1 e35, respectively. FISH-positive cases showed two types of signals, single 3′ signals (green) and split red and green signals. Using FISH as a standard method, the sensitivity and specificity of ROS1 IHC with 1+ staining or more were 100% and 96.67%, respectively. The sensitivity and specificity of RT-PCR were both 100%. Univariate analysis identified female sex (P=0.044), Stage I disease (P<0.001), and ROS1-negative status (P=0.022) to be significantly associated with longer overall survival.ConclusionIHC, FISH, and RT-PCR are all effective methods for the detection of ROS1 rearrangement. IHC would be a useful screening method in routine pathologic laboratories. RT-PCR can detect exact fusion patterns. ROS1 rearrangement may be a worse prognostic factor. The exact correlation of ROS1 rearrangement with prognosis and whether different fusion types are correlated with different responses to targeted therapy need to be further investigated.

Purpose: Oncogenic fusions involving the neuregulin 1 (NRG1) gene are found in approximately 0.2% of cancers of diverse histologies. The resulting chimeric NRG1 proteins bind predominantly to HER3, leading to HER3-HER2 dimerization and activation of downstream growth and survival pathways. HER3 is, therefore, a rational target for therapy in NRG1 fusion-driven cancers.Experimental Design: We developed novel patient-derived and isogenic models of NRG1-rearranged cancers and examined the effect of the anti-HER3 antibody, seribantumab, on growth and activation of signaling networks in vitro and in vivo.Results: Seribantumab inhibited NRG1-stimulated growth of MCF-7 cells and growth of patient-derived breast (MDA-MB-175-VII, DOC4-NRG1 fusion) and lung (LUAD-0061AS3, SLC3A2-NRG1 fusion) cancer cells harboring NRG1 fusions or NRG1 amplification (HCC-95). In addition, seribantumab inhibited growth of isogenic HBEC cells expressing a CD74-NRG1 fusion (HBECp53-CD74-NRG1) and induced apoptosis in MDA-MB-175-VII and LUAD-0061AS3 cells. Induction of proapoptotic proteins and reduced expression of the cell-cycle regulator, cyclin D1, were observed in seribantumab-treated cells. Treatment of MDA-MB-175-VII, LUAD-0061AS3, and HBECp53-CD74-NRG1 cells with seribantumab reduced phosphorylation of EGFR, HER2, HER3, HER4, and known downstream signaling molecules, such as AKT and ERK1/2. Significantly, administration of seribantumab to mice bearing LUAD-0061AS3 patient-derived xenograft (PDX) and OV-10-0050 (ovarian cancer with CLU-NRG1 fusion) PDX tumors induced regression of tumors by 50%-100%. Afatinib was much less effective at blocking tumor growth.Conclusions: Seribantumab treatment blocked activation of the four ERBB family members and of downstream signaling, leading to inhibition of NRG1 fusion-dependent tumorigenesis in vitro and in vivo in breast, lung, and ovarian patient-derived cancer models.

Primary breast diffuse large B-cell lymphoma (DLBCL) is a rare non-Hodgkin's lymphoma with limited data. In this study, a population-based study of primary breast DLBCL in the United States was performed to determine its incidence trends, prognostic factors, survival, the role of surgery as well as the comparison with nodal DLBCL. 1021 patients diagnosed with breast DLBCL were identified in the Surveillance, Epidemiology, and End Results (SEER) cancer registries from 1973-2014. The incidence of both breast and nodal DLBCL increased over time. Patients with breast DLBCL were older, mainly women, diagnosed at earlier stages and had lower prevalence in white and black races compared with nodal DLBCL. Multivariate analysis revealed older age (≥ 70 years old) and advanced stage as independent predictors of worse OS. Independent predictor of better DSS were younger age (< 70 years old), early stage and diagnosis after 2000. When analyzed according to age, stage, race, tumor laterality and year of diagnosis, the overall survival did not benefit from surgery except in patients diagnosed between 2001-2010 and the surgery rate decreased overtime. Compared with nodal DLBCL, breast DLBCL patients exhibited a better outcome. In conclusion, breast DLBCL is a rare tumor with increasing incidence and improved survival over the last four decades. The introduction of rituximab seems to improve the outcome of breast DLBCL. Further studies are needed to advance our understanding of breast DLBCL and optimize the treatment strategy.

Current prognostic indicators are ineffective for identifying advanced-stage colorectal cancer (CRC) patients with high risk of recurrence after surgical resection. We investigated the prognostic value of p53, Ki-67, and programmed death ligand 1 (PD-L1) in 254 patients with stage II and III CRC. The expression of p53 was positive in 63% of cases. Up-regulation of p53 was associated with smaller tumor size (P=.001) and higher Ki-67 labeling index (LI) (P=.031). The tumor Ki-67 LI was high (≥20%) in 197 (78%) of the patients. High Ki-67 LI was associated with higher TNM stage (P=.031), positive p53 expression (P=.031), and negative PD-L1 expression (P=.003). The 5-year relapse-free survivals (RFS) were 53% and 89%, respectively, for the p53-positive and Ki-67 LI-high patients and the p53-negative and Ki-67 LI-low patients (P<.001). In univariate analysis, negative p53 (P=.001), low Ki-67 LI (P=.006), low PD-L1 expression (P=.044), low TNM stage (P<.001), rectosigmoid location (P=.026), and small size (P=.013) were significantly related to RFS. In multivariate Cox regression analysis, positive p53 expression (hazard ratio [HR]: 2.48; 95% confidence interval: 1.34-4.59, P=.004), high Ki-67 LI (HR, 2.62; 95% CI, 1.12-6.14, P=.027) and high TNM stage (HR, 2.598; 95% CI, 1.55-4.37, P<.001,) were independent predictors of unfavorable prognosis. In summary, PD-L1, Ki-67, and p53 staining individually had significant prognostic value for patients with stage II and III CRC. Moreover, combining p53 H-score ≥35 and Ki-67 LI ≥20% identifies patients with poor clinical outcome.

Chondroitin polymerizing factor (CHPF) is an important glycosyltransferase involved in the biosynthesis of chondroitin sulfate. However, the relationship between CHPF and gastric cancer has not been fully investigated. CHPF expression in gastric cancer tissues was detected by immunohistochemistry and correlated with gastric cancer patient prognosis. Cultured gastric cancer cells and human gastric epithelial cell line GES1 were used to investigate the effects of shCHPF and shE2F1 on the development and progression of gastric cancer by MTT, western blotting, flow cytometry analysis of cell apoptosis, colony formation, transwell and gastric cancer xenograft mouse models, in vitro and in vivo. In gastric cancer tissues, CHPF was found to be significantly upregulated, and its expression correlated with tumor infiltration and advanced tumor stage and shorter patient survival in gastric cancer. CHPF may promote gastric cancer development by regulating cell proliferation, colony formation, cell apoptosis and cell migration, while knockdown induced the opposite effects. Moreover, the results from in vivo experiments demonstrated that tumor growth was suppressed by CHPF knockdown. Additionally, E2F1 was identified as a potential downstream target of CHPF in the regulation of gastric cancer, and its knockdown decreased the CHPF-induced promotion of gastric cancer. Mechanistic study revealed that CHPF may regulate E2F1 through affecting UBE2T-mediated E2F1 ubiquitination. This study showed, for the first time, that CHPF is a potential prognostic indicator and tumor promoter in gastric cancer whose function is likely carried out through the regulation of E2F1.