Purpose: Non-small cell lung cancer (NSCLC) with KRAS mutation may be resistant to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI). This study aims to evaluate a plasma-based KRAS mutation analysis and the clinical significance of plasma KRAS mutation as a predictive marker for tumor resistance to EGFR-TKIs in patients with NSCLC.Experimental Design: DNA extracted from plasma and matched tumor tissues were obtained from 273 patients with advanced stage NSCLC. Patients were followed up prospectively for treatment outcomes. KRAS mutations in codon 12 and 13 were detected using PCR-restriction fragment length polymorphism. Mutations in plasma and matched tumors were compared. Associations between KRAS mutation status and patients' clinical outcomes were analyzed.Results: KRAS mutation was found in 35 (12.8%) plasma samples and 30 (11.0%) matched tumor tissues. The consistency of KRAS mutations between plasma and tumors is 76.7% (23 of 30; κ = 0.668; P < 0.001). Among 120 patients who received EGFR-TKI treatment, the response rate was only 5.3% (1 of 19) for patients with plasma KRAS mutation compared with 29.7% for patients with no KRAS mutation in plasma DNA (P = 0.024). The median progression-free survival time of patients with plasma KRAS mutation was 2.5 months compared with 8.8 months for patients with wild-type KRAS (P < 0.001).Conclusions: KRAS mutation in plasma DNA correlates with the mutation status in the matched tumor tissues of patients with NSCLC. Plasma KRAS mutation status is associated with a poor tumor response to EGFR-TKIs in NSCLC patients and may be used as a predictive marker in selecting patients for such treatment. Clin Cancer Res; 16(4); 1324-30. ©2010 AACR.Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) such as gefitinib and erlotinib are selective TKIs that can block the intracellular receptor binding sites of ATP, thus inhibiting the downstream signaling transmission. Several EGFR-TKIs have been approved as second-or third-line agents for advanced non-small cell lung cancer (NSCLC) patients who failed in platinumbased chemotherapy (1, 2).The discovery that EGFR tyrosine kinase domain mutations were strongly associated with greater sensitivity of NSCLC to EGFR-TKIs in vitro and higher response rates in clinical studies provided rationale for using molecular markers to identify patients who are most likely to benefit from EGFR-TKI therapy. Subsequent prospective studies focusing on exploring the possibility of EGFR-TKIs as first-line therapy, such as IPASS (IRESSA Pan-Asia Study, a phase III, randomized, open-label, first-line study of gefitinib versus carboplatin/paclitaxel in clinically selected patients with advanced NSCLC in Asia) and the Spanish Lung Cancer Group trial (a multicenter prospective phase II trial of customized erlotinib for advanced NSCLC patients with EGFR mutations), have shown an outstanding survival benefit for patients with EGFR mutant tumors who received first-line EGFR-TKI therapy, which is superior to the outc...

PurposeWe aimed to investigate the feasibility of droplet digital PCR (ddPCR) for the quantitative and dynamic detection of EGFR mutations and next generation sequencing (NGS) for screening EGFR-tyrosine kinase inhibitors (EGFR-TKIs) resistance-relevant mutations in circulating tumor DNA (ctDNA) from advanced lung adenocarcinoma (ADC) patients.ResultsDetection limit of EGFR mutation in ctDNA by ddPCR was 0.04%. Taking the EGFR mutation in tumor tissue as the golden standard, the concordance of EGFR mutations detected in ctDNA was 74% (54/73). Patients with EGFR mutation in ctDNA (n = 54) superior progression-free survival (PFS, median, 12.6 vs. 6.7 months, P < 0.001) and overall survival (OS, median, 35.6 vs. 23.8 months, P = 0.028) compared to those with EGFR wild type in ctDNA (n = 19). Patients with high EGFR-mutated abundance in ctDNA (> 5.15%) showed better PFS compared to those with low EGFR mutated abundance (≤ 5.15%) (PFS, median, 15.4 vs. 11.1 months, P = 0.021). NGS results showed that 66.6% (8/12) total mutational copy number were elevated and 76.5% (26/34) mutual mutation frequency increased after disease progression.MethodsSeventy-three advanced ADC patients with tumor tissues carrying EGFR mutations and their matched pre- and post-EGFR-TKIs plasma samples were enrolled in this study. Absolute quantities of plasma EGFR mutant and wild-type alleles were measured by ddPCR. Multi-genes testing was performed using NGS in 12 patients.ConclusionsDynamic and quantitative analysis of EGFR mutation in ctDNA could guide personalized therapy for advanced ADC. NGS shows good performance in multiple genes testing especially novel and uncommon genes.

Pulmonary sarcomatoid carcinoma (PSC) is a rare subtype of lung cancer with poor prognosis. Here, we perform multi-omics analysis of 56 PSC samples, 14 of which are microdissected to analyze intratumoral heterogeneity. We report the mutational landscape of PSC. The epithelial and sarcomatoid components share numerous genomic alterations, indicating a common progenitor. We find that epithelial-mesenchymal transition (EMT) plays important roles in the carcinogenesis of PSC. The pan-cancer analysis reveals high tumor mutation burden and leukocyte fraction of PSC. Integrated molecular classification shows three subgroups with distinct biology, prognosis and potential therapeutic strategies. Actionable mutations are enriched in C1 and C2, patients in C3 have a significantly longer overall survival, and C1 and C2 exhibit T-cell inflamed microenvironments. The three subgroups show molecular similarities to specific subtypes of conventional lung cancer. In conclusion, our study reveals the molecular characteristics and provides entry points for the treatment of PSC.

BackgroundEGFR mutation is a strong predictive factor of EGFR-TKIs therapy. However, at least 10% of patients with EGFR wild-type are responsive to TKIs, suggesting that other determinants of outcome besides EGFR mutation might exist. We hypothesized that activation of phosphorylated EGFR could be a potential predictive biomarker to EGFR-TKIs treatment among patients in wild-type EGFR.MethodTotal of 205 stage IIIb and IV NSCLC patients, tissue samples of whom were available for molecular analysis, were enrolled in this study. The phosphorylation of EGFR at tyrosine 1068 (pTyr1068) and 1173 (pTyr1173) were assessed by immunohistochemistry, and EGFR mutations were detected by denaturing high performance liquid chromatograph (DHPLC).ResultsAmong 205 patients assessable for EGFR mutation and phosphorylation analysis, 92 (44.9%) were EGFR mutant and 165 patients (57.6%) had pTyr1173 expression. Superior progression-free survival (PFS) was seen after EGFR-TKIs therapy in patients with pTyr1068 expression compared to pTyr1068 negative ones (median PFS 7.0 months vs. 1.2 months, P < 0.001). Inversely, patients with pTyr1173 had a shorter PFS (4.8 months VS. 7.7 months, P = 0.016). In subgroup of patients with wild-type EGFR, pTyr1068 expression positive ones had a significantly prolonged PFS (4.2 months vs.1.2 months P < 0.001) compared with those without pTyr1068 expression. Sixteen patients with both wild-type EGFR and pTyr1068 who responded to EGFR-TKIs had median PFS of 15.6 months (95%CI: 7.28-23.9).ConclusionpTyr1068 may be a predictive biomarker for screening the population for clinical response to EGFR-TKIs treatment; especially for patients with wild-type EGFR.

In the present study, proteins differentially expressed between gastric cancer tissue and para-tumoral normal gastric tissues were screened, and the function of the highly expressed protein c1QTNF6 in gastric carcinoma was investigated. The differential expression of mRNAs extracted from the tumor and adjacent tissues was analyzed using Genechip assay. An AGS si-c1QTNF6 cell line was constructed using shRNA-c1QTNF6 lentivirus. The cell invasion and migration ability of c1QTNF6-knockdown cells were determined by Transwell chamber migration and wound healing assays, respectively. The effects of c1QTNF6 on AGS cell cycle distribution and apoptosis were detected using a FACScan flow cytometer. The results demonstrated that the expression of 109 genes was increased and the expression of 129 was decreased in tumor tissues. Among these genes, the c1QTNF6 gene was highly expressed in tumor tissues and the AGS7901 cell line. c1QTNF6-knockdown decreased the cell growth, and the proliferative and migration ability, as well as increasing the apoptosis of gastric carcinoma cells. In addition, the number of AGS cells in the G2/M phase was significantly increased after 5 days of c1QTNF6-shRNA lentivirus infection. The results of the present study indicated that c1QTNF6 serves an important role in the development of gastric carcinoma. c1QTNF6 is involved in promoting the proliferation and migration, and in reducing the apoptosis of gastric carcinoma cells. These results provided a potential therapeutic target for the treatment of gastric carcinoma.

The empirical criteria for defining a clinical subtype of lung cancer are gradually transiting from histopathology to genetic variations in driver genes. Targeting these driver mutations, such as sensitizing epidermal growth factor receptor (EGFR) mutations, has dramatically improved the prognosis of advanced non-small cell lung cancer (NSCLC). However, the clinical benefit of molecularly targeted therapy on NSCLC appears to be different between lung adenocarcinomas and squamous cell carcinomas (SqCCs). We report here that the resistance of lung SqCC harboring EGFR mutations to EGFR tyrosine kinase inhibitors (EGFR-TKIs) was due to the activation of BMP-BMPR-Smad1/5-p70S6K. The combined treatment of these tumor cells with EGFR-TKI, together with inhibitors specific to BMPR or downstream mTOR, effectively reversed the resistance to EGFR-TKI. Moreover, blocking the whole PI3K-AKTmTOR pathway with the PI3K/mTOR dual inhibitor BEZ235 also showed efficacy in treating this subtype of lung SqCC. This study details the empirical basis for a feasible clinical solution for squamous cell carcinomas with EGFR mutations.epidermal growth factor receptor tyrosine kinase inhibitor | lung squamous cell carcinoma | bone morphogenetic proteins | drug resistance

BackgroundIt is well known that genetic alternation of epidermal growth factor receptor (EGFR) plays critical roles in tumorgenesis of lung cancer and can predict outcome of non-small-cell lung cancer treatment, especially the EGFR tyrosine-kinase inhibitors (EGFR-TKIs) therapy. However, it is unclear whether epigenetic changes such as DNA methylation involve in the response to the EGFR-TKI therapy.MethodsTumor samples from 155 patients with stages IIIB to IV NSCLC who received EGFR-TKI therapy were analyzed for DNA methylation status of Wnt antagonist genes, including SFRP1, SFRP2, SFRP5, DKK3, WIF1, and APC, using methylation specific PCR (MSP) method. EGFR mutations detections were performed in the same tissues samples using Denaturing High Performance Liquid Chromatography (DHPLC).ResultsWe found that Wnt antagonists tend to methylate simultaneously. Methylation of sFRP1 and sFRP5 are reversely correlated with EGFR mutation (P = 0.005, P = 0.011). However, no correlations of methylations of other Wnt antagonist genes with EGFR mutation were found. The patients with methylated SFRP5 have a significant shorter progression free survival than those with unmethylated SFRP5 in response to EGFR-TKI treatment (P = 0.002), which is independent of EGFR genotype.ConclusionsPatients with unmethylated SFRP5 are more likely to benefit from EGFR-TKI therapy.

Homeotransplantation of bones for replacement therapy have been demonstrated reliably in clinical data. However, human donor bones applicable for homeotransplantation are in short supply, which facilitates the search for suitable alternatives, such as xenografts grafts. The α-Gal antigen-related immune risk of xenografts directly affects the safety and effectiveness of the biomaterials and limits their applications in the clinic. The immune risk can be prevented by depletion or breaking anti-Gal antibody prior to transplant. Therefore, how to assess the immune risk of the bone substitutes and select the reliable animal research model become extremely important. In this study, we prepared lyophilized bone substitutes (T1) and Guanghao Biotech bone substitutes (T2, animal-derived biomaterials with α-Gal antigen decreased), aimed to assess the immune risk of xenografts bone substitutes on GGTA1 knockout mice. The α-Gal antigen contents of T1 and T2 were firstly detected by ELISA method in vitro. The bone substitutes were then implanted subcutaneously into GGTA1 knockout mice for 2, 4 and 12 weeks, respectively. The total serum antibody levels, anti-α-Gal antibody levels, inflammatory cytokine and splenic lymphocyte surface molecules were detected and histology analysis of skin and thymus were performed to systematically evaluate the immune response caused by the T1 and T2 bone substitutes in mice. In vitro results showed that the amount of α-Gal epitopes in T1 bone substitutes was significantly higher than T2 bone substitutes, and the clearance rate of α-Gal antigen in T2 bone substitutes achieved about 55.6%. Results of antibody level in vivo showed that the T1 bone substitutes group possessed significantly higher total IgG, IgM, IgA and anti-α-Gal IgG levels than T2 and control group, while T2 group showed no significant changes of these indexes compared with control. In terms of inflammatory cytokines, T1 bone substitutes showed evidently higher levels of IL-4, IL-12P70 and IL-10 than T2 and control, while T2 group was comparable to control. No changes in the levels of splenic lymphocyte surface molecules were found in the three groups (T1, T2 and control group) during the experimental periods. The pathological results demonstrated that the inflammatory response in T2 group was lighter than the T1 group, which was in accordance with the inflammatory cytokines levels. The above results indicated that the process of antigen removal effectively reduced the α-Gal antigens content in T2 bone substitutes, which caused little immune response in vivo and could be used as bone healing materials. This study also demonstrated that GGTA1 knockout mice can be used as a routine tool to assess the immune risk of animal-derived biomaterials.