Enrichment of alterations in targetable molecular pathways in KRAS wild-type (WT) pancreatic cancer (PC).

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. 4629-4629
Author(s):  
Philip Agop Philip ◽  
Joanne Xiu ◽  
Michael J. Hall ◽  
Andrew Eugene Hendifar ◽  
Emil Lou ◽  
...  

4629 Background: Genomic profiling has identified KRAS mutations in 88-90% of PC. KRAS WT tumors represent a molecularly heterogeneous group that may harbor targetable alterations (TA). We studied KRAS WT PC using NextGen sequencing (NGS) and whole transcriptome sequencing (WTS) to characterize the molecular landscape of this unique group and to assess the prevalence of TA. Methods: A total of 1164 PC tumors were tested at Caris Life Sciences by NGS (592 genes), WTS (NovaSeq), IHC and fragment analysis. Comparison of KRAS WT vs. mutant (MT) was done by Fisher-Exact or Chi2 and was corrected for multiple tests. Results: The KRAS WT cohort included 144 tumors (12.4%). No differences were seen in gender (female: 46% in both WT & MT) and age (median: 66 & 67) compared to KRAS MT. In KRAS WT tumors, targetable fusions tested by WTS and pathogenic mutations by NGS were seen in 22% (32 of 144) and 52% (75 of 144) respectively; potentially targetable amplifications (amp) were seen in 5 additional tumors. No TA were seen in 22% of WT tumors. Key alterations are in Table. Alterations inducing MAPK activation, including BRAF, RAF1, NF1 and GNAS changes were seen in 38 (26%) tumors. Frequent alterations were seen in FGFR genes (11 tumors), MET (4, including 1 exon 14 skip), and ERBB receptor and ligands (10). Fusions in ALK, ROS1, RET and NOTCH1 were seen (8), largely exclusive of other drivers. Wnt, PI3K, chromatin remodeling (CR) and DDR changes were common and sometimes seen concurrent with other alterations. Compared to KRAS MT, no difference of PD-L1 or TMB-H was seen. BRAF, APC, PBRM1, CTNNB1 mutations, MDM2 amp, gene fusions and MSI-H/dMMR were all more frequent in KRAS WT tumors (corrected p < 0.05). Conclusions: KRAS WT PC is enriched with TA (e.g., BRAF, ALK, ROS1, NRG1, MSI-H). The use of WTS in combination with NGS identifies activated molecular pathways in the majority of KRAS WT tumors. Based on our findings, comprehensive profiling of PC at the DNA and RNA level is recommended to provide patients with therapeutic opportunities beyond standard treatments. [Table: see text]

2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 109-109
Author(s):  
Fadel S. Alyaqoub ◽  
Pawan Noel ◽  
Szabolcs Szelinger ◽  
Thanemozhi G. Natarajan ◽  
Susan M. Dombrowski ◽  
...  

109 Background: Gastrointestinal cancers (GIC) account for 26% of global cancer incidence and 35% of cancer-related deaths. We investigated the molecular landscape and therapeutic targets across 18 types of GIC using whole exome (WES) and whole transcriptome sequencing (WTS). Methods: GEM ExTra assay was performed on 603 paired samples (ages 18-90 years, median = 61 years). Targeted sequence coverage was 180X for germline DNA and 400X for tumor DNA. Reportable somatic alterations included single base substitutions, indels, Copy Number Alterations, gene fusions, alternate transcripts, as well as tumor mutational burden (TMB) and microsatellite instability (MSI) status. Germline subtraction identified somatic-specific alterations. Results: Analysis of 603 GIC patient samples, including esophageal, gastric cancer (GC), biliary tract (BT), pancreatic cancer (PC), colorectal cancer (CRC), and other cancers, identified 434 actionable targets. The median number of alterations was 3 per GIC patient. The 5 most common actionable alterations were in APC, KRAS, CDKN2A, ARID1A and PIK3CA. Activation of Wnt signaling was found in 264/603 (44%), with the majority being in CRC cases. Alterations in cell cycle genes including CDKN2A, CDK4/6 and others were noted in 129/603 (21%) cases, with the majority in PC, suggesting benefit from CDK4/6 inhibitors. Activation of PI3K/PTEN/Akt/mTOR pathway was noted in 105/603 (17%), with the majority harbored in CRC, suggesting benefit from targeting this pathway. ERBB2 amplification and mutations were noted in 22/603 (4%) across different GIC tumor types. Alterations in homologous recombination genes predicting platinum and PARP inhibitor response was noted in 181/603 (30%) samples distributed across GIC subtypes. KRAS (G12C) mutation was found in 7% of all KRAS mutations across GIC subtypes, thus allowing patients to enroll in clinical trials with G12C-specific inhibitors. The majority of cases with MSI- and TMB-high status were identified in GC and CRC tumors and may be predictive of response to immunotherapy. WTS identified actionable fusions, including FGFR1/2/3 and novel NRG1 fusions in BT cancers. Conclusions: Our study revealed actionable targets used in patient selection for precision therapies, in addition to other mutational profiles of clinical significance. Overall, comprehensive genomic profiling enabled detection of established and novel actionable alterations, including fusions, which may have gone undetected using hotspot panels.


2021 ◽  
pp. 106689692110313
Author(s):  
Alexander M. Strait ◽  
Julia A. Bridge ◽  
Anthony J. Iafrate ◽  
Marilyn M. Li ◽  
Feng Xu ◽  
...  

Myofibroblastoma is a rare, benign stromal tumor with a diverse morphologic spectrum. Mammary-type myofibroblastoma (MTMF) is the extra-mammary counterpart of this neoplasm and its occurrence throughout the body has become increasingly recognized. Similar morphologic variations of MTMF have now been described which mirror those seen in the breast. We describe a case of intra-abdominal MTMF composed of short fascicles of eosinophilic spindle cells admixed with mature adipose tissue. The spindle cells stained diffusely positive for CD34, desmin, smooth muscle actin, and h-caldesmon by immunohistochemistry. Concurrent loss of RB1 (13q14) and 13q34 loci were confirmed by fluorescence in situ hybridization whereas anchored multiplex PCR and whole transcriptome sequencing did not reveal any pathognomonic fusions suggesting an alternative diagnosis. To the best of our knowledge this is the first documented case of leiomyomatous variant of MTMF.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1107
Author(s):  
Marie-Albane Minati ◽  
Maxime Libert ◽  
Hajar Dahou ◽  
Patrick Jacquemin ◽  
Mohamad Assi

Pancreatitis, an inflammation of the pancreas, appears to be a main driver of pancreatic cancer when combined with Kras mutations. In this context, the exact redox mechanisms are not clearly elucidated. Herein, we treated mice expressing a KrasG12D mutation in pancreatic acinar cells with cerulein to induce acute pancreatitis. In the presence of KrasG12D, pancreatitis triggered significantly greater redox unbalance and oxidative damages compared to control mice expressing wild-type Kras alleles. Further analyses identified the disruption in glutathione metabolism as the main redox event occurring during pancreatitis. Compared to the wild-type background, KrasG12D-bearing mice showed a greater responsiveness to treatment with a thiol-containing compound, N-acetylcysteine (NAC). Notably, NAC treatment increased the pancreatic glutathione pool, reduced systemic markers related to pancreatic and liver damages, limited the extent of pancreatic edema and fibrosis as well as reduced systemic and pancreatic oxidative damages. The protective effects of NAC were, at least, partly due to a decrease in the production of tumor necrosis factor-α (TNF-α) by acinar cells, which was concomitant with the inhibition of NF-κB(p65) nuclear translocation. Our data provide a rationale to use thiol-containing compounds as an adjuvant therapy to alleviate the severity of inflammation during pancreatitis and pancreatic tumorigenesis.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 4035-4035
Author(s):  
Deqiang Wang ◽  
Xiaofeng Chen ◽  
Yaping Xu ◽  
Yuange He ◽  
Lifeng Li ◽  
...  

4035 Background: Gastric adenocarcinoma (GAC) is with a complex microenvironment of tumor cells. A better understanding of the immune landscape of GACs may lead to the improved treatment strategies with ICIs. Methods: To determine whether the molecular characteristics can serve in prognostic stratification of GACs, tumor tissue and blood samples were collected from 231 GAC patients. The median follow-up time was 34 months. The TCR profile was determined by TCR-β CDR3 sequencing while mutation and gene expression profiles were determined by whole exon and whole transcriptome sequencing, respectively. Tumour-infiltrating immune cells were characterized using immunofluorescence (IF) staining. Results: The results showed the OS of patients with high levels of TCR clonality (TCR clonal expansion) was significantly improved compared with patients with low levels (HR = 1.80 and 2.22, p = 0.022 and 0.008, respectively) in the whole group and in the subgroup of patients with stages IB to III disease. Furthermore, low local clonality was an independent risk factor for OS (adjusted-HR = 1.68 and 1.95, p = 0.049 and 0.029, respectively). Thus, TCR clonal expansion in tumour tissue had a strong prognostic value for GAC patients, independent of clinicopathological factors. Based on whole exon and whole transcriptome sequencing, RNF43/FBXW7/ARID2 mutations and local TCR clonality jointly impacted prognosis (p < 0.001), and functional changes in corresponding Wnt pathway/Notch pathway/SWI/SNF complex characterized a GAC subset with enhanced tumour immunogenicity and TCR clonal expansion. TCR CDR3 sequence similarity comparisons yielded clusters of TCR clones of likely similar functions. The most expansive TCR clusters negatively correlated with the percentage of subclonal mutations (Pearson r = -0.8183, p < 0.001), indicating that tumors with less genomic heterogeneity might induce a greater immune response. By IF staining and mutual correlation analysis, only M1 macrophages showed a significant positive correlation with local TCR clonality for epithelia, stroma, and total cell counts. Tumors were categorized according to the density of M1 macrophages, M1 macrophage infiltrated subtype was associated with favorable OS (p = 0.040 and 0.043) and its combination with the local TCR clonality improved prognosis stratification (p < 0.001). Finally, the scoring by local TCR clonality, RNF43/FBXW7/ARID2 mutations and M1 infiltration determined the best prognosis (p < 0.001). Conclusions: TCR profiles were associated with genomic alterations and may serve as a prognostic biomarker for GACs. A multi-omic model including TCR profiles might produce an improved stratification for treatments and outcomes.


2020 ◽  
Vol 117 (24) ◽  
pp. 13329-13338
Author(s):  
James K. Carrow ◽  
Kanwar Abhay Singh ◽  
Manish K. Jaiswal ◽  
Adelina Ramirez ◽  
Giriraj Lokhande ◽  
...  

Two-dimensional (2D) molybdenum disulfide (MoS2) nanomaterials are an emerging class of biomaterials that are photoresponsive at near-infrared wavelengths (NIR). Here, we demonstrate the ability of 2D MoS2to modulate cellular functions of human stem cells through photothermal mechanisms. The interaction of MoS2and NIR stimulation of MoS2with human stem cells is investigated using whole-transcriptome sequencing (RNA-seq). Global gene expression profile of stem cells reveals significant influence of MoS2and NIR stimulation of MoS2on integrins, cellular migration, and wound healing. The combination of MoS2and NIR light may provide new approaches to regulate and direct these cellular functions for the purposes of regenerative medicine as well as cancer therapy.


2020 ◽  
Author(s):  
Fei Yao ◽  
Chuanren Zhou ◽  
Qiyou Huang ◽  
Xiaoying Huang ◽  
Jie Chen ◽  
...  

Abstract Background: Chemo-resistance is a major clinical obstacle to the treatment of colorectal cancer (CRC), mRNAs and non-coding RNAs (ncRNAs) have been reported to modulate the development of chemo-resistance. However, the profiles of mRNAs and ncRNAs as well as competing endogenous RNA (ceRNA) networks in CRC chemo-resistance are still unclear, and whether different drug resistance of CRC have the same mechanisms also needs to be explored. This study aims to uncover the expression of mRNAs and ncRNAs in parental cell lines and different chemo-resistant cell lines, and construct ceRNA regulatory networks by whole-transcriptome sequencing.Methods: The expression of mRNAs and ncRNAs in parental cell lines and drug-resistant cell lines were identified by whole-transcriptome sequencing and bioinformatics methods.Results: A total of 1779 mRNAs, 64 miRNAs, 11 circRNAs and 295 lncRNAs were common differentially expressed in two different chemo-resistant cell lines when compared with the control. In addition, 5,767 lncRNA-miRNA-mRNA relationship pairs and 47 circRNA-miRNA-mRNA pathways were constructed according to ceRNA regulatory rules, in which AC109322.2-hsa-miR-371a-5p-BTNL3 and hsacirc_027876-hsa-miR-582-3p-FREM1 were identified as the most potential ceRNA networks involved in drug resistance to CRC. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of two ceRNA regulatory networks showed that the TNF signaling pathway may be crucial in the process of CRC drug resistance.Conclusions: A large number of mRNAs and ncRNAs in chemo-resistant cell lines were different expressed, which may play pivotal roles in development of drug resistance through the ceRNA regulatory network. This study may improve our understanding of the underlying mechanisms and provide a promising therapeutic strategy for CRC chemo-resistance.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi55-vi55
Author(s):  
Adam Lauko ◽  
Assad Ali ◽  
Soumya Sagar ◽  
Addison Barnett ◽  
Hong Li ◽  
...  

Abstract BACKGROUND Immunotherapy is increasingly used in patients with non-small cell lung cancer brain metastases (NSCLCBM). KRAS mutations are associated with worse prognosis and there is no FDA approved targeted therapy. KRAS mutations are associated with increased expression of PD-L1. We evaluated the outcomes of NSCLCBM with KRAS mutations treated with immune checkpoint inhibitors (ICI). METHODS We reviewed 800 patients with NSCLCBM treated at our tertiary care center. 226 had known KRAS mutational status, 121 of which received immunotherapy. Overall survival (OS) was calculated from either the start of immunotherapy (when both groups received immunotherapy) or from the date of diagnosis of brain metastasis. Kaplan-Meier method and Cox Proportional hazard model were utilized to determine differences in OS and the Chi-square test was utilized to determine differences in PD-L1 expression. RESULTS In 109 patients where both KRAS and PD-L1 status were known, KRAS mutations had greater PD-L1 expression (80.1% vs 61.9% positive, p=0.04). There was no difference in OS between KRAS mutant vs KRAS wild-type patients treated with immunotherapy. Median survival from the start of immunotherapy was 15.6 vs 15.5 months respectively (p=0.7), after adjusting for age, KPS, lesion number and extra-cranial metastasis (HR = .91, p=.7). Patients with KRAS mutations treated with immunotherapy versus those who received chemotherapy had a 1-year OS from the diagnosis of brain metastasis of 60.9% vs 38.7% respectively (trending towards significance, p=0.05). KRAS wild-type patients treated with immunotherapy versus those who did not receive immunotherapy had a 1-year OS from the diagnosis of brain metastasis of 61.9% vs 62.5% (p=0.85), respectively. DISCUSSION KRAS mutations are associated with increased PD-L1 expression. Use of immunotherapy negates the poor outcomes seen traditionally in patients with NSCLCBM and KRAS mutations and it improves survival compared to use of chemotherapy. Our experience supports the use of immunotherapy in these patients.


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