Anti-leukemic effects of simvastatin on NRASG12D mutant acute myeloid leukemia cells.

The statins are a group of therapeutic drugs widely used for lowering plasma cholesterol level, while it has also been reported to induce cell death in human acute myeloid leukemia (AML) cells. To determine antitumor activity triggered by simvastatin, four AML cell lines-U937, KG1, THP1 (NRASG12D mutant) and HL60 (NRASQ61L mutant)-were cultured with simvastatin and cell viability was assessed using the CellTiter-Glo reagent. For understanding mechanism of antitumor activity, immunoblot analysis for pAkt (Ser473), Akt, pMEK, MEK, pERK (Thr202/Tyr204) and ERK (Thr202/Tyr204) was performed. Apoptotic cell population was calculated using the Annexin V-FITC assay, and cell cycle state was assessed by flow cytometry. Simvastatin showed different cytotoxic effect among AML cells, of which NRASG12D mutant THP1 was the most statin sensitive cell line (IC50 values: 1.96 uM in HL60, 7.87 uM in KG1, 0.83 uM in THP1 and 1.37 uM in U937). Western blot analysis revealed that Ras downstream signaling molecules including Akt, MEK, and ERK1/2 were markedly inhibited in THP1 cells compared to other AML cells when exposed to simvastatin. In addition, only in THP1 cells, increased apoptosis and cell cycle arrest by simvastatin was observed. The combination of simvastatin and MEK inhibitor AZD6244 synergistically reduced THP1 cell proliferation compared to simvastatin alone and AZD6244 alone (IC50 values: 0.88 uM in simvastatin, 0.32 uM in AZD6244, and 0.23 uM in combination of simvastatin and AZD6244). Simvastatin exhibited anti-leukemic effect in human AML cells in vitro, especially at NRASG12D mutant AML cell line.

HER2-positive gastric cancer with concomitant MET and/or EGFR overexpression: a distinct subset of patients for dual inhibition therapy.

Growth factor receptors, often carrying tyrosine kinase activities in their cytoplasmic domains, are overexpressed in many cancers. Coactivation of receptor tyrosine kinases (RTKs) plays a critical role in tumor response to targeted therapeutics. We examined concomitant overexpression of EGFR and MET in patients with HER2(+) and HER2(-) gastric cancers (GCs). Tissue microarray samples obtained from 1,589 GC patients who received R0 gastrectomy with extensive node dissection and adjuvant chemoradiationtherapy were analyzed by immunohistochemistry and fluorescence in situ hybridization. HER2(+) was observed in 169 patients (11%). Out of 169 HER2(+) patients, 15 (9%) were EGFR(+) and MET(+) , 29 (17%) were EGFR(+) , 37 (22%) were MET(+) and the remaining 88 patients (52%) were HER2(+) only, without concomitant EGFR or MET overexpression. Greater number of overexpressed RTKs correlated with younger age (p < 0.001), larger tumor size (p = 0.027), intestinal histology (p < 0.001) and shorter overall survival (p = 0.002). The mean overall survival was 113 months for HER2(-) /EGFR(-) /MET(-) and 63 months for HER2(+) /EGFR(+) /MET(+) subgroups. Patients with HER2(+) /EGFR(+) /MET(+) GCs had a substantial risk of death with a hazard ratio of 3.01 (95% CI: 1.54-5.90), compared with HER2(-) /EGFR(-) /MET(-) GC patients. Using patient-derived tumor cell models isolated from pericardial effusion of HER2(+) and MET(+) GC cases, we demonstrated that the combination of HER2-inhibitor (lapatinib) and MET-inhibitor offered a more profound inhibition in the ERK/AKT pathway and cell proliferation than lapatinib alone. Co-overexpression of RTKs was demonstrated in small subsets of GC associated with aggressive behavior and in these cases, combination therapy may be considered as potential treatment options.

Identification of ROS1 rearrangement in gastric adenocarcinoma.

BACKGROUND: Recently, chromosomal rearrangements involving receptor tyrosine kinases (RTKs) have been described in common epithelial malignancies, including nonsmall cell lung cancer (NSCLC), colorectal cancer, and breast cancer. One of these RTKs, c-ros oncogene 1, receptor tyrosine kinase (ROS1), has been identified as a driver mutation in NSCLC, because its inhibition by crizotinib, an anaplastic lymphoma receptor tyrosine kinase (ALK)/met proto-oncogene hepatocyte growth factor receptor (MET)/ROS1 inhibitor, led to significant tumor shrinkage in ROS1-rearranged NSCLC. Currently, only human epidermal growth factor 2 (HER2)-targeted therapy in combination with chemotherapy has been successful in significantly prolonging the survival of patients with advanced gastric cancer (GC). There is a need for the discovery of additional novel targets in GC. METHODS: Anti-ROS1 immunohistochemistry (IHC) was used to screen 495 GC samples and was followed by simultaneous ROS1 break-apart fluorescence in situ hybridization (FISH) and reverse transcriptase-polymerase chain reaction (RT-PCR) analyses in IHC-positive samples. Fusion partners in ROS1-rearranged GC were determined by RT-PCR. In all 495 samples, HER2 amplification was identified with FISH, and MET expression was identified by IHC. RESULTS: Twenty-three tumor samples were ROS1 IHC-positive. Three of 23 patients were ROS1 FISH positive, HER2 FISH negative, and negative for MET overexpression; and 2 of those 3 patients harbored a solute carrier family 34 (sodium phosphate), member 2 (SLC34A2)-ROS1 fusion transcripts. No fusion partner was identified in the third patient. Both patients who had SLC34A2-ROS1 transcripts had poorly differentiated histology with recurrence and death within 2 years of curative surgery. ROS1 IHC-positive status was not identified as an independent prognostic factor for overall survival. CONCLUSIONS: In this study, an SLC34A2-ROS1 rearrangement was identified in GC, and the results provide a rationale for investigating the clinical efficacy of ROS1 inhibitors in this unique molecular subset of GC. Society.

Uremia induces functional incompetence of bone marrow-derived stromal cells.

BACKGROUND: Chronic kidney disease (CKD) is associated with increased risk for cardiovascular diseases (CVD). We hypothesized that inadequate angiogenic response in uremic patients could result from dysfunction of bone marrow-derived stromal cells [mesenchymal stem cells (MSCs)]. METHODS: We investigated whether MSCs are functionally competent in uremia induced by partial kidney ablation in C57Bl/6J mice. RESULTS: Uremic MSCs showed decreased expression of vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)1 and stromal cell-derived factor (SDF)-1α, increased cellular senescence, decreased proliferation, defects in migration in response to VEGF and SDF-1α and in vitro tube formation. Interestingly, the expression of fibroblast-specific protein-1 was higher in uremic MSCs. Uremia decreased hypoxia-inducible factor-1α, VEGF and VEGFR1 expression under hypoxia and Akt phosphorylation in both basal and VEGF-stimulated states. A diminished mitogenic effect on endothelial proliferation was observed in conditioned media from uremic MSCs. In addition, intravital microscopic analysis showed decreased angiogenesis in uremic MSCs. CONCLUSION: These results clearly demonstrate the functional incompetence in MSCs under uremic conditions and may significantly contribute to the disproportionately high risk for CVD in patients with CKD.

Dysregulated miRNA in a cancer-prone environment: A study of gastric non-neoplastic mucosa.

Understanding cancer-prone environments is important to efficiently detect and prevent cancers. The associations between miRNA and cancer-prone environments are still largely unknown in gastric cancer (GC). Six miRNAs that are differentially expressed during gastric carcinogenesis were selected, and quantitative real-time PCR was performed in an independent training set (fresh non-tumor and tumor samples from 18 GC patients) and validation sets (set 1 with formalin-fixed paraffin-embedded non-tumor and tumor samples from 19 solitary GC and set 2 with 37 multiple GC patients). The results were compared with those of 37 gastric mucosa from 20 healthy volunteers. The expression levels of miR-26a, miR-375, and miR-1260 in gastric mucosa from healthy volunteers were statistically higher than that of non-tumorous gastric mucosa located 3 cm apart from the GC in the training set (miR-26a, P < 0.0001; miR-375, P = 0.0049; miR-1260, P = 0.0172), validation set 1 (miR-26a and miR-375, P < 0.0001; miR-1260, P = 0.0008), and validation set 2 (miR-26a, miR-375, and miR-1260, P < 0.0001). And a combination of miR-26a and miR-1260 showed the highest area under the curve value of 0.89. miRNAs are differentially expressed in non-neoplastic gastric mucosa and can be used as a biomarker to predict cancer-prone environments.

CDH1 mutations in gastric cancers are not associated with family history.

CDH1 mutation is the most frequent genetic alteration in hereditary diffuse gastric cancer (GC) and early onset diffuse GC patients. However, the incidence of CDH1 mutations in sporadic GC with or without family history has not been studied. This retrospective study includes a total of 993 Korean patients with primary advanced GC who underwent surgery and received palliative chemotherapy. Targeted deep sequencing was performed in all cases and family history of GC was searched with survival analysis. We found CDH1 alterations in 146 of 993 patients (14.7 %) and 8 were germline (0.8 %). Out of 146 patients with CDH1 mutations, 25 (17.1 %) had a family history of GC in one of their first relatives, and 12 patients (8.2 %) were diagnosed with familial GC (FGC). All cases with FGC were diffuse type by Lauren classification, and only one harbored a previously reported germline mutation of CDH1 (c.2638 G > A) and the remaining 11 harbored known somatic CDH1 mutations. Among all patients with CDH1 mutation, there was no significant survival difference between patients with family history or FGC. In the 847 patients without CDH1 mutation, 189 (22.3 %) had a family history of GC and 92 patients (10.9 %) were FGC. CDH1 mutations were more frequent in patients with early onset (<45 years) GC (45.5 %) compared with patients with late onset GC (10.9 %) (p = 0.001), but were not significantly associated with the family history of GC (p > 0.05). CDH1 mutations are mostly somatic and typically are not associated with family history.

PD-L1 expression in gastric cancer determined by digital image analyses: pitfalls and correlation with pathologist interpretation.

Programmed death ligand-1 (PD-L1) immunohistochemistry is used to predict response to anti-PD-L1 therapy. However, intra- and inter-observer variability influence the prediction of PD-L1 expression. Unlike evaluations of non-small cell lung cancer according to PD-L1 expression determined by tumor proportion score, gastric cancer is evaluated using combined positive scores. We aimed to compare the results of digital image analysis and pathologists' interpretations for predicting response to pembrolizumab in gastric cancer patients. Gastric cancer tissues from patients enrolled in a clinical trial of pembrolizumab were reviewed, and 39 cases were analyzed. PD-L1 22C3 PharmDx (Dako) immunohistochemistry slides were interpreted by digital image analysis and by the consensus of two pathologists, and the results of interpretations were compared with the eventual clinical responses to pembrolizumab. In direct comparisons of digital image analyses and pathologists' interpretations, 33 (84.6%) out of 39 cases showed concordant results. In 6 (15.4%) cases, weak staining of PD-L1, anthracotic pigment deposits, or decalcification artifacts caused discordant results, and all the cases were challenging. In statistical analyses, PD-L1 expression as interpreted by pathologists and digital image analysis did not differ significantly for predicting responses to pembrolizumab (P = 0.1856). Digital image analyses and pathologists' interpretations showed concordant results for PD-L1 combined positive scores in most cases, and the prediction performances of each were not significantly different.

MicroRNA Expression Profiles in Gastric Carcinogenesis.

Intestinal-type gastric carcinoma exhibits a multistep carcinogenic sequence from adenoma to carcinoma with a gradual increase in genomic alterations. But the roles of microRNAs (miRNA) in this multistage cascade are not fully explored. To identify differentially expressed miRNA (DEM) during early gastric carcinogenesis, we performed miRNA microarray profiling with 24 gastric cancers and precursor lesions (7 early gastric cancer [EGC], 3 adenomas with high-grade dysplasia, 4 adenomas with low-grade dysplasia, and 10 adjacent normal tissues). Alterations in the expression of 132 miRNA were detected; these were categorized into three groups based on their expression patterns. Of these, 42 miRNAs were aberrantly expressed in EGC. Five miRNA (miR-26a, miR-375, miR-574-3p, miR-145, and miR-15b) showed decreased expression since adenoma. Expression of two miRNA, miR-200C and miR-29a, was down-regulated in EGCs compared to normal mucosa or adenomas. Six miRNA (miR-601, miR-107, miR-18a, miR-370, miR-300, and miR-96) showed increased expression in gastric cancer compared to normal or adenoma samples. Five representative miRNAs were further validated with RT-qPCR in independent 77 samples. Taken together, these results suggest that the dysregulated miRNA show alterations at the early stages of gastric tumorigenesis and may be used as a candidate biomarker.

Antitumor Effect of AZD4547 in a Fibroblast Growth Factor Receptor 2-Amplified Gastric Cancer Patient-Derived Cell Model.

BACKGROUND: FGFR2 amplification is associated with aggressive gastric cancer (GC), and targeted drugs have been developed for treatment of GC. We evaluated the antitumor activity of an FGFR inhibitor in FGFR2-amplified GC patients with peritoneal carcinomatosis. METHODS: Two GC patients with FGFR2 amplification confirmed by fluorescence in situ hybridization showed peritoneal seeding and malignant ascites. We used the patient-derived xenograft model; patient-derived cells (PDCs) from malignant ascites were used to assess FGFR2 expression and its downstream pathway using immunofluorescence analysis and immunoblot assay in vitro. Apoptosis and cell cycle arrest after treatment of FGFR inhibitor were analyzed by Annexin V-FITC assay and cell cycle analysis. RESULTS: FGFR2 amplification was verified in both PDC lines. AZD4547 as an FGFR inhibitor decreased proliferation of PDCs, and the IC50 value was estimated to be 250 nM in PDC#1 and 210 nM in PDC#2. FGFR inhibitor also significantly decreased levels of phosphorylated FGFR2 and downstream signaling molecules in FGFR2-amplified PDC lines. In cell cycle analysis, apoptosis was significantly increased in AZD4547-treated cells compared with nontreated cells. The proportion of cells in the sub-G1 stage was significantly higher in AZD4547-treated PDCs than in control cells. CONCLUSION: Our findings suggest that FGFR2 amplification is a relevant therapeutic target in GC with peritoneal carcinomatosis.

MerTK is a novel therapeutic target in gastric cancer.

INTRODUCTION: The role of MerTK has not been assessed in gastric cancer (GC). The aim of this study was to identify a subgroup of GC patients with MerTK tumor overexpression, and to evaluate MerTK as a potential therapeutic target in this disease. METHODS: Protein and mRNA expression of MerTK were evaluated, and other various in vitro analyses including shRNA transfection, cell cycle anslysis, MTS assay and colony forming assay were carried out with GC cell lines and GC patient-derived cells (PDCs). RESULTS: shRNA-mediated knockdown of MerTK resulted in inhibition of cell growth, as well as increased cellular apoptosis in MerTK positive GC cells. Out of 192 GC patients, 16 (8.3%) patients showed strong protein expression and they had a significantly shorter overall survival compared to those with no MerTK expression. In 54 cases of GC PDCs, 4 cases (7.4%) showed mRNA overexpression, which was comparable to the protein expression rate. When we administered UNC1062, a novel MerTK-selective small molecular tyrosine kinase inhibitor, proliferation of MerTK overexpressing GC cells and PDCs were considerably inhibited. CONCLUSION: MerTK may be involved in GC carcinogenesis, and it could be a potential novel therapeutic target in GC patients.

Acquired resistance to LY2874455 in FGFR2-amplified gastric cancer through an emergence of novel FGFR2-ACSL5 fusion.

BACKGROUND: Fibroblast growth factor 2 (FGFR2) amplification, occurring in ~2-9% of gastric cancers (GC), is associated with poor overall survival. RESULTS: RNA sequencing identified a novel FGFR2-ACSL5 fusion in the resistant tumor that was absent from the matched pre-treatment tumor. The FGFR2-amplified PDC line was sensitive to FGFR inhibitors whereas the PDC line with concomitant FGFR2 amplification and FGFR2-ACSL5 fusion exhibited resistance. Additionally, the FGFR2-amplified GC PDC line, which was initially sensitive to FGFR2 inhibitors, subsequently also developed resistance. MATERIALS AND METHODS: We identified an FGFR2-amplified patient with GC, who demonstrated a dramatic and long-term response to LY2874455, a pan-FGFR inhibitor, but eventually developed an acquired LY2874455 resistance. Following resistance development, an endoscopic biopsy was performed for transcriptome sequencing and patient-derived tumor cell line (PDC) establishment to elucidate the underlying molecular alterations. CONCLUSIONS: FGFR inhibitors may function against FGFR2-amplified GC, and a novel FGFR2-ACSL5 fusion identified by transcriptomic characterization may underlie clinically acquired resistance. IMPLICATIONS FOR PRACTICE: Poor treatment response represents a substantial concern in patients with gastric cancer carrying multiple FGFR2 gene copies. Here, we show the utility of a general FGFR inhibitor for initial response prior to treatment resistance and report the first characterization of a potential resistance mechanism involving an FGFR2-ACSL5 fusion protein.

Development of Novel Patient-Derived Preclinical Models from Malignant Effusions in Patients with Tyrosine Kinase Inhibitor-Resistant Clear Cell Renal Cell Carcinoma.

PURPOSE: Although targeting angiogenesis with tyrosine kinase inhibitors (TKIs) has become standard of care in the treatment of clear cell renal cell carcinoma (RCC), resistance mechanism are not fully understood, and there is a need to develop new therapeutic options overcoming them. METHODS AND MATERIALS: To develop a preclinical model that predicts clinical activity of novel agents in 19 RCC patients, we established patient-derived cell (PDC) and xenograft (PDX) models derived from malignant effusions or surgical specimen. RESULTS: Successful PDCs, defined as cells that maintained growth following two passages, were established in 5 of 15 malignant effusions and 1 of 4 surgical specimens. One PDC, clinically refractory to TKIs, was implanted and engrafted in mice, resulting in a comparable histology to the primary tumor. The PDC-PDX model also showed similar genomic features when tested using targeted sequencing of cancer-related genes. When we examined the drug effects of the PDX model, the tumor cells showed resistance to TKIs and everolimus in vitro. CONCLUSION: The results suggest that the PDC-PDX preclinical model we developed using malignant effusions can be a useful preclinical model to interrogate sensitivity to targeted agents based on genomic alterations.

BEZ235 (PIK3/mTOR inhibitor) Overcomes Pazopanib Resistance in Patient-Derived Refractory Soft Tissue Sarcoma Cells.

BACKGROUND: Although pazopanib treatment has become the standard chemotherapy in salvage setting for metastatic sarcoma patients, most patients progress after pazopanib treatment in 4 to 6 months. After failure to pazopanib, patients have limited options for treatment. Therefore, subsequent therapy in patients who failed to pazopanib is urgently needed and the use of patient derived cells or patient derived tumors for accompanying testing with various pharmacological inhibitors could offer additional treatment options for these patients. METHODS: Patient derived tumor cells were collected from ascites at the time of progression to pazopanib and a 13-drug panel was tested for drug sensitivity. We confirmed the results using in vitro cell viability assay and immunoblot assay. We also performed the genomic profiling of PDX model. RESULTS: The growth of patient derived tumor cells was significantly reduced by exposure to 1.0 µM AZD2014 compared with control (control versus AZD2014, mean growth = 100.0% vs 16.04%, difference = 83.96%, 95% CI = 70.01% to 97.92%, P = .0435). Similarly, 1.0 µM BEZ235 profoundly inhibited tumor cell growth in vitro when compared to control (control versus BEZ235, mean growth = 100.0% vs 7.308%, difference = 92.69%, 95% CI = 78.87% to 106.5%, P < .0001). Despite the presence of CDK4 amplification in the patient-derived tumor cells, LEE011 did not considerably inhibit cell proliferation when compared with control (control vs LEE011, mean growth = 100.0% vs 80.23%, difference = 19.77%, 95% CI = 1.828% to 37.72%, P = .0377). The immunoblot analysis showed that BEZ235 treatment decreased pAKT, pmTOR and pERK whereas AZD2014 decreased only pmTOR. CONCLUSION: Taken together, upregulation of mTOR/AKT pathway in sarcoma patient derived cells was considerably inhibited by the treatment of AZD2014 and BEZ235 with downregulation of AKT pathway (greater extent for BEZ235). These molecules may be considered as treatment option in STS patient who have failed to pazopanib in the context of clinical trials.

Genomic Alterations in Biliary Tract Cancer Using Targeted Sequencing.

BACKGROUND: Biliary tract cancers (BTCs) are rare and heterogeneous group of tumors classified anatomically into intrahepatic and extrahepatic bile ducts and gallbladder adenocarcinomas. Patient-derived tumor cell (PDC) models with genome analysis can be a valuable platform to develop a method to overcome the clinical barrier on BTCs. MATERIAL AND METHODS: Between January 2012 and June 2015, 40 BTC patients' samples were collected. PDCs were isolated and cultured from surgical specimens, biopsy tissues, or malignant effusions including ascites and pleural fluid. Genome analysis using targeted panel sequencing as well as digital multiplexed gene analysis was applied to PDCs as well as primary tumors. RESULTS: Extrahepatic cholangiocarcinoma (N=15, 37.5%), intrahepatic cholangiocarcinoma (N=10, 25.0%), gallbladder cancer (N=14, 35.0%), and ampulla of Vater cancer (N=1, 2.5%) were included. We identified 15 mutations with diverse genetic alterations in 19 cases of BTC from primary tumor specimens. The most common molecular alterations were in TP53 (8/19, 42.1%), including missense mutations such as C242Y, E285K, G112S, P19T, R148T, R248Q, and R273L. We also detected two NRAS mutations (G12C and Q61L), two KRAS mutations (G12A and G12S), two ERBB2 mutations (V777L and pM774delinsMA) and amplification, and three PIK3CA mutations (N345K, E545K, and E521K). PDC models were successfully established in 27 of 40 samples (67.5%), including 22/24 from body fluids (91.7%) and 5/16 from tissue specimens (31.3%). CONCLUSIONS: PDC models are promising tools for uncovering driver mutations and identifying rational therapeutic strategies in BTC. Application of this model is expected to inform clinical trials of drugs for molecular-based targeted therapy.

Molecular characterization of colorectal cancer patients and concomitant patient-derived tumor cell establishment.

BACKGROUND: We aimed to establish a prospectively enrolled colorectal cancer (CRC) cohort for targeted sequencing of primary tumors from CRC patients. In parallel, we established collateral PDC models from the matched primary tumor tissues, which may be later used as preclinical models for genome-directed targeted therapy experiments. RESULTS: In all, we identified 27 SNVs in the 6 genes such as PIK3CA (N = 16), BRAF (N = 6), NRAS (N = 2), and CTNNB1 (N = 1), PTEN (N = 1), and ERBB2 (N = 1). RET-NCOA4 translocation was observed in one out of 105 patients (0.9%). PDC models were successfully established from 62 (55.4%) of the 112 samples. To confirm the genomic features of various tumor cells, we compared variant allele frequency results of the primary tumor and progeny PDCs. The Pearson correlation coefficient between the variants from primary tumor cells and PDCs was 0.881. METHODS: Between April 2014 and June 2015, 112 patients with CRC who underwent resection of the primary tumor were enrolled in the SMC Oncology Biomarker study. The PDC culture protocol was performed for all eligible patients. All of the primary tumors from the 112 patients who provided written informed consent were genomically sequenced with targeted sequencing. In parallel, PDC establishment was attempted for all sequenced tumors. CONCLUSIONS: We have prospectively sequenced a CRC cohort of 105 patients and successfully established 62 PDC in parallel. Each genomically characterized PDCs can be used as a preclinical model especially in rare genomic alteration event.

The effect of acupuncture on anxiety and neuropeptide Y expression in the basolateral amygdala of maternally separated rats.

Recent studies have suggested that maternally deprived rats exhibit anxiogenic-like behavior when exposed to stress in later life. Neuropeptide Y (NPY) is involved in the regulation of various physiological functions such as the expression of anxiety. Female Wistar rat pups were separated from their mothers for 3h daily from postnatal days 3 (P3) to 14 (P14). Acupuncture groups were treated with acupuncture at Shenmen (HT7) or Zusanli (ST36) on alternate days from P50 to P62. Their anxiety-like behavior was evaluated using an elevated plus-maze at P62, and then NPY immunohistochemistry in the basolateral amygdala (BLA) was performed. Rats exposed to maternal separation (MS) were less likely to explore the open arms of the plus-maze compared to control rats that were not exposed to MS. Among maternally separated groups, the percentage of time spent in the open arms was significantly increased in the HT7 acupuncture group, but not the ST36 acupuncture group, compared to MS group. In accordance with this behavior, the numbers of NPY-immunoreactive cells in the BLA were lower in the MS group compared to the control group. Among maternally separated groups, the numbers of NPY-immunoreactive cells in the BLA were significantly higher in the HT7 acupuncture group, but not higher in the ST36 acupuncture group, compared to MS group. These findings suggest that acupuncture treatment might reduce anxiety-like behavior in adult rats following maternal separation by modulating the NPY system in the amygdala.

Gastrointestinal malignancies harbor actionable MET exon 14 deletions.

Recently, MET exon 14 deletion (METex14del) has been postulated to be one potential mechanism for MET protein overexpression. We screened for the presence of METex14del transcript by multiplexed fusion transcript analysis using nCounter assay followed by confirmation with quantitative reverse transcription PCR with correlation to MET protein expression by immunohistochemistry (IHC) and MET amplification by fluorescence in situ hybridization (FISH). We extracted RNAs from 230 patients enrolled onto the prospective molecular profiling clinical trial (NEXT-1) (NCT02141152) between November 2013 and August 2014. Thirteen METex14del cases were identified including 3 gastric cancer, 4 colon cancer, 5 non-small cell lung cancer, and one adenocarcinoma of unknown primary. Of these 13 METex14del cases, 11 were MET IHC 3+ and 2 were 2+. Only one out of the 13 METex14del cases was MET amplified (MET/CEP ratio > 2.0). Growths of two (gastric, colon) METex14del+ patient tumor derived cell lines were profoundly inhibited by both MET tyrosine kinase inhibitors and a monoclonal antibody targeting MET. In conclusion, METex14del is a unique molecular aberration present in gastrointestinal (GI) malignancies corresponding with overexpression of MET protein but rarely with MET amplification. Substantial growth inhibition of METex14del+ patient tumor derived cell lines by several MET targeting drugs strongly suggests METex14del is a potential actionable driver mutation in GI malignancies.

NTRK1 rearrangement in colorectal cancer patients: evidence for actionable target using patient-derived tumor cell line.

BACKGROUND: We have investigated the incidence of NTRK1 rearrangements in metastatic gastrointestinal cancer patients and demonstrated the potential for clinical response of these patients to targeted therapy. METHODS: We prospectively collected tumor tissue specimens for one year and simultaneously generated patient-derived tumor cells (PDCs). Specimens were initially screened for TrkA protein expression using TrkA immunohistochemistry (IHC). In the case of TrkA IHC positive results, samples were further examined by fluorescence in situ hybridization (FISH) and next generation sequencing (NGS) to confirm the presence of NTRK1 rearrangements. RESULTS: From January 2014 to December 2014, a total of 74 metastatic colorectal cancer (CRC) patients and 66 gastric cancer (GC) patients were initially screened by TrkA IHC. Two of the 74 CRC patients (2.7%) and one of the 66 GC patients (1.5%) were positive for TrkA expression by IHC. All three IHC positive cases had evidence of NTRK1 rearrangements by FISH. NGS was performed on the 3 IHC positive cases and confirmed TPM3-NTRK1 rearrangements in the two CRC cases. One GC patient with TrkA expression by IHC did not harbor an NTRK1 rearrangement. PDCs established from the NTRK1 positive CRC patients were positive for the NTRK1 rearrangement. Entrectinib, a pan-TRK inhibitor, profoundly inhibited cell proliferation of NTRK1-rearranged PDCs with such inhibition associated with inactivation of TrkA, and down-regulation of downstream signaling pathways. CONCLUSIONS: TrkA IHC is an effective, initial screening method for NTRK1 rearrangement detection in the clinic. Inhibition of the TrkA kinase is a promising targeted therapy for cancer patients whose tumors harbor a NTRK1 rearrangement.

Patient-derived cell models as preclinical tools for genome-directed targeted therapy.

BACKGROUND: In this study, we established patient-derived tumor cell (PDC) models using tissues collected from patients with metastatic cancer and assessed whether these models could be used as a tool for genome-based cancer treatment. METHODS: PDCs were isolated and cultured from malignant effusions including ascites and pleural fluid. Pathological examination, immunohistochemical analysis, and genomic profiling were performed to compare the histological and genomic features of primary tumors, PDCs. An exploratory gene expression profiling assay was performed to further characterize PDCs. RESULTS: From January 2012 to May 2013, 176 samples from patients with metastatic cancer were collected. PDC models were successfully established in 130 (73.6%) samples. The median time from specimen collection to passage 1 (P1) was 3 weeks (range, 0.5-4 weeks), while that from P1 to P2 was 2.5 weeks (range, 0.5-5 weeks). Sixteen paired samples of genomic alterations were highly concordant between each primary tumor and progeny PDCs, with an average variant allele frequency (VAF) correlation of 0.878. We compared genomic profiles of the primary tumor (P0), P1 cells, P2 cells, and patient-derived xenografts (PDXs) derived from P2 cells and found that three samples (P0, P1, and P2 cells) were highly correlated (0.99-1.00). Moreover, PDXs showed more than 100 variants, with correlations of only 0.6-0.8 for the other samples. Drug responses of PDCs were reflective of the clinical response to targeted agents in selected patient PDC lines. CONCLUSION(S): Our results provided evidence that our PDC model was a promising model for preclinical experiments and closely resembled the patient tumor genome and clinical response.

Detection of novel and potentially actionable anaplastic lymphoma kinase (ALK) rearrangement in colorectal adenocarcinoma by immunohistochemistry screening.

PURPOSE: Anaplastic lymphoma kinase (ALK) rearrangement has been detected in colorectal carcinoma (CRC) using advanced molecular diagnostics tests including exon scanning, fluorescence in situ hybridization (FISH), and next generation sequencing (NGS). We investigated if immunohistochemistry (IHC) can be used to detect ALK rearrangement in gastrointestinal malignancies. EXPERIMENTAL DESIGNS: Tissue microarrays (TMAs) from consecutive gastric carcinoma (GC) and CRC patients who underwent surgical resection at Samsung Medical Center, Seoul, Korea were screened by IHC using ALK monoclonal antibody 5A4. IHC positive cases were confirmed by FISH, nCounter assays, and NGS-based comprehensive genomic profiling (CGP). ALK IHC was further applied to CRC patients enrolled in a pathway-directed therapeutic trial. RESULTS: Four hundred thirty-two GC and 172 CRC cases were screened by IHC. No GC sample was ALK IHC positive. One CRC (0.6%) was ALK IHC positive (3+) that was confirmed by ALK FISH and a novel CAD-ALK (C35; A20) fusion variant that resulted from a paracentric inversion event inv(2)(p22-21p23) was identified by CGP. One out of 50 CRC patients enrolled in a pathway-directed therapeutic trial was ALK IHC positive (3+) confirmed by ALK FISH and found to harbor the EML4-ALK (E21, A20) fusion variant by CGP. Growth of a tumor cell line derived from this EML4-ALK CRC patient was inhibited by ALK inhibitors crizotinib and entrectinib. CONCLUSIONS: ALK IHC is a viable screening strategy for identifying ALK rearrangement in CRC. ALK rearrangement is a potential actionable driver mutation in CRC based on survival inhibition of patient tumor-derived cell line by potent ALK inhibitors.