Although immune checkpoint inhibitors have resulted in durable clinical benefits in a subset of patients with advanced cancer, some patients who did not respond to initial anti–PD-1 therapy have been found to benefit from the addition of salvage chemotherapy. However, the mechanism responsible for the successful chemoimmunotherapy is not completely understood. Here we show that a subset of circulating CD8 + T cells expressing the chemokine receptor CX3CR1 are able to withstand the toxicity of chemotherapy and are increased in patients with metastatic melanoma who responded to chemoimmunotherapy (paclitaxel and carboplatin plus PD-1 blockade). These CX3CR1 + CD8 + T cells have effector memory phenotypes and the ability to efflux chemotherapy drugs via the ABCB1 transporter. In line with clinical observation, our preclinical models identified an optimal sequencing of chemoimmunotherapy that resulted in an increase of CX3CR1 + CD8 + T cells. Taken together, we found a subset of PD-1 therapy–responsive CD8 + T cells that were capable of withstanding chemotherapy and executing tumor rejection with their unique abilities of drug efflux (ABCB1), cytolytic activity (granzyme B and perforin), and migration to and retention (CX3CR1 and CD11a) at tumor sites. Future strategies to monitor and increase the frequency of CX3CR1 + CD8 + T cells may help to design effective chemoimmunotherapy to overcome cancer resistance to immune checkpoint blockade therapy.
A mutational comparison of adult and adolescent and young adult (AYA) colon cancer
AbstractBackgroundAdenosine signaling has been implicated in several neurological and psychiatric disorders. Previously, we found that astrocytic excitatory amino acid transporter 2 (EAAT2) and aquaporin 4 (AQP4) are downregulated in the striatum of mice lacking type 1 equilibrative nucleoside transporter (ENT1).MethodsTo further investigate the gene expression profile in the striatum, we preformed Illumina Mouse Whole Genome BeadChip microarray analysis of the caudate–putamen (CPu) and nucleus accumbens (NAc) inENT1 null mice. Gene expression was validated byRT‐PCR, Western blot, and immunofluorescence. Using transgenic mice expressing enhanced green fluorescence protein (EGFP) under the control of the glial fibrillary acidic protein (GFAP) promoter, we examinedEGFPexpression in anENT1 null background.ResultsGlial fibrillary acidic protein was identified as a top candidate gene that was reduced in ENT1 null mice compared to wild‐type littermates. Furthermore, EGFP expression was significantly reduced in GFAP‐EGFP transgenic mice in an ENT1 null background in both the CPu and NAc. Finally, pharmacological inhibition or siRNA knockdown of ENT1 in cultured astrocytes also reduced GFAPmRNAlevels.ConclusionsOverall, our findings demonstrate thatENT1 regulatesGFAPexpression and possibly astrocyte function.
Abstract LB-346: MiRNA and gene expression signatures in lung adenocarcinoma from never-smokers
Abstract Lung cancer is the most common cause of smoking-related mortality in worldwide. However, approximately 10 to 25 % cases are not attributable to smoking. Cumulative evidence suggests that lung cancer from never smokers (<100 cigarettes lifetime) may develop via molecular mechanisms that are different from lung cancers in smokers. Recently, miRNAs have been identified as a new class of regulatory molecules that participate in a variety of biological processes. Because each miRNAs can potentially target a large set of mRNA making and therefore may play a critical role in lung tumorigenesis and patient outcome, we sought to examine the role of miRNA in lung adenocarcinoma among never smokers. A total of 298 samples were analyzed in this study including 168 fresh frozen (FF) tissues from 88 lung adenocarcinomas and 80 adjacent non-involved lung tissues; and 132 formalin-fixed paraffin embedded (FFPE) tissues from 68 tumors and 64 normal lung samples. Gene expression profiling was performed for miRNA and mRNA using Illumina Whole Genome DASL platform. We identified 20 miRNAs with the most significant expression changes between the tumor and normal in both FF and FFPE samples (Fold change > 1.5, p <0.01, FDR <0.05). We also examined mRNA expression signature using 56 matched FF tumors and normal lung tissues. Cox proportional hazard analysis was performed independently for both FF and FFPE cohorts and showed that increased expression of mir-708 was strongly associated with an increased risk of patient death after adjusting for age, sex and tumor stage (FF cohort, HR =1.92; 95% CI =1.02–3.63; p < 0.05 and FFPE cohort, HR=1.90; 95% CI=1.08–3.34; P < 0.05). Candidate biological targets of mir-708 were identified using TargetScan and MicroCosm Targets databases. A total of 13 candidate genes were found and one of these genes, CMT11 (Candidate Mir-708 Target), was down-regulated 1.6 fold on average in tumors that were high in mir-708 expression. Based on the sequence, CMT11 is a novel transmembrane protein. In Cox analysis, reduced CMT11 expression was strongly correlated with an increased risk of death in patients (HR = 2.43, 95% CI = 1.17 − 5.26; P <0.01). Functionally, overexpression of mir-708 in A549 and HEK293T cells significantly increased the rate of cellular proliferation and migration. Over expression of mir-708 in HEK293T cells also repressed ∼70% of the luciferase activity when the reporter RNA contained the 3′ UTR of CMT11. Recently, several studies have showed mir-708 is a potential squamous cell lung cancer marker and one of miRNAs that may predict the recurrence of Stage I lung cancer after surgical resection. Additional evidence also suggests that CMT11 is a negative regulator of Wnt-signaling pathway. Our data provides clinical and functional evidence supporting an important role of mir-708 in lung cancer progression and identifies CMT11 as a down stream target gene mediating this process. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-346. doi:10.1158/1538-7445.AM2011-LB-346
EGFR Somatic Mutations in Lung Tumors: Radon Exposure and Passive Smoking in Former- and Never-Smoking U.S. Women
Previous linkage analysis of an Asian population proposed possible candidate genes for mandibular prognathism, such as Matrilin-1 (cartilage matrix protein). To investigate the association between the single-nucleotide polymorphisms (SNPs) in Matrilin-1 and mandibular prognathism, we investigated three sequence variants (-158 T>C, 7987 G>A, 8572 C>T) in 164 mandibular prognathism patients and 132 control individuals with a normal occlusion. The results showed that the 8572 TT genotypes in Matrilin-1 showed increased risk of mandibular prognathism (OR = 9.28, 95% Cl = 1.19~197.57, P < 0.05), whereas the 7987 AA genotype showed a protective effect for mandibular prognathism (OR = 0.16, 95% Cl = 0.05~0.47, P < 0.05). Genotyping results showed that the Matrilin-1 polymorphism haplotype TGC (ht4; 158T, 7987G, and 8572C alleles) had a pronounced risk effect for mandibular prognathism compared with controls (OR = 5.16, 95% Cl = 2.03~13.93, P < 0.01). The results suggest that polymorphisms in Matrilin-1 could be used as a marker for genetic susceptibility to mandibular prognathism.