YAP1 as a Novel Negative Biomarker of Immune Checkpoint Inhibitors for EGFR-Mutant Non-Small-Cell Lung Cancer.

Background: Immune checkpoint inhibitors (ICIs) have become a standard care in non-small-cell lung cancer (NSCLC). However, its application to epidermal growth factor receptor (EGFR)-mutant NSCLC patients is confronted with drug resistance. This study aimed to clarify the potential role of Yes1-associated transcriptional regulator (YAP1) in ICIs treatment for EGFR-mutant NSCLC population. Methods: All the clinical data of NSCLC were downloaded from Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) for GSE11969 and GSE72094. Based on YAP1 expression, all the NSCLC patients including the EGFR-mutant and EGFR-wildtype (WT) patients were divided into two groups, YAP1_High and YAP1_Low. Using cBioPortal, genetic alterations were analyzed for identification of immunogenicity in EGFR-mutant NSCLC. MR analysis was used to analyze the hub gene of EGFR. The infiltration of immune cells and the expression of the identified tumor-associated antigens were identified with TIMER. By graph learning-based dimensionality reduction analysis, the immune landscape was visualized. Moreover, survival analysis was performed to verify the predictive value of YAP1 in ICIs treatment for EGFR-mutant NSCLC population using Ren's research data (NCT03513666). Results: YAP1 was a poor prognostic factor of EGFR-mutant NSCLC population rather than lung adenocarcinoma (LUAD) patients. MR analysis revealed that the EGFR gene regulated YAP1 expression. YAP1 was identified as a hub gene closely associated with immunosuppressive microenvironment and poor prognosis in EGFR-mutant NSCLC population in TCGA LUAD. Tumors with YAP1_High showed an immune-"cold" and immunosuppressive phenotype, whereas those with YAP1_Low demonstrated an immune-"hot" and immunoactive phenotype. More importantly, it was verified that YAP1_High subpopulation had a significantly shorter progression-free survival (PFS) and overall survival (OS) after ICIs treatment in EGFR-mutant NSCLC patients in the clinical trial. Conclusions: YAP1 mediates immunosuppressive microenvironment and poor prognosis in EGFR-mutant NSCLC population. YAP1 is a novel negative biomarker of ICIs treatment in EGFR-mutant NSCLC population. Clinical Trials. This trial is registered with NCT03513666.

Concurrent EGFR-TKI and Thoracic Radiotherapy as First-Line Treatment for Stage IV Non-Small Cell Lung Cancer Harboring EGFR Active Mutations.

LESSONS LEARNED: This single-arm, phase II study shows that concurrent EGFR-tyrosine kinase inhibitor plus thoracic radiotherapy as the first-line treatment for stage IV non-small cell lung cancer harboring EGFR active mutations provides long-term control for the primary lung lesion, and 1-year progression-free survival (PFS) rate and median PFS are numerically higher than those of the erlotinib monotherapy.Serious adverse events are acceptable, although grade >3 radiation pneumonitis occurred in 20% of patients. BACKGROUND: Studies show effective local control by EGFR-tyrosine kinase inhibitor (TKI) combined with radiotherapy at metastatic sites in advanced lung cancer harboring EGFR active mutations. Salvage local radiotherapy is associated with prolonged progression-free survival (PFS) in local disease during EGFR-TKI treatment. However, no prospective study has been reported on concurrent EGFR-TKI and radiotherapy for primary lung lesions. This study investigated the efficacy and safety of first-line EGFR-TKI combined with thoracic radiotherapy in treating stage IV non-small cell lung cancer (NSCLC) harboring EGFR active mutations. METHODS: We conducted a single-arm, phase II clinical trial. Each patient received EGFR-TKI (erlotinib 150 mg or gefitinib 250 mg per day) plus thoracic radiotherapy (54-60 Gy/27-30 F/5.5-6 w) within 2 weeks of beginning EGFR-TKI therapy until either disease progression or intolerable adverse events (AEs) appeared. RESULTS: From January 2015 to March 2018, 401 patients were screened, and 10 patients (5 male and 5 female) were eligible. These patients had a median age of 55 years (40-75) and median follow-up of 19.8 months (5.8-34). The 1-year PFS rate was 57.1%, median PFS was 13 months, and median time to progression of irradiated lesion (iTTP) was 20.5 months. Objective response rate (ORR), was 50% and disease control rate (DCR) was 100%. The most common grade ≥3 AEs were radiation pneumonitis (20%) and rash (10%). One patient died after rejecting treatment for pneumonitis. The others received a full, systematic course of glucocorticoid therapy. Pneumonitis was all well controlled and did not relapse. CONCLUSION: Concurrent EGFR-TKI plus thoracic radiotherapy as the first-line treatment for stage IV NSCLC harboring EGFR active mutations shows a long-term control of primary lung lesion. The 1-year PFS rate and median PFS of this combined therapy are numerically higher than those of the erlotinib monotherapy. The risk of serious adverse events is acceptable.

Case report: primary resistance to osimertinib in erlotinib-pretreated lung adenocarcinoma with EGFR T790 M mutation.

BACKGROUND: Among non-small cell lung cancer (NSCLC) patients with acquired T790 M mutation resistance to first-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), 71% are likely to benefit from osimertinib. There have been several reports about the secondary resistance to osimertinib treatment in T790 M-positive patients, while primary resistance to osimertinib has been rarely reported. CASE PRESENTATION: A 62-year-old Asian male never smoker who presented with stage IV EGFR L858R-positive adenocarcinoma developed EGFR T790 M mutation after 14 months of treatment with erlotinib combined with thoracic radiotherapy as first-line therapy. The patient was initiated on osimertinib treatment with T790 M mutation detected (14.4%), but disease progressed 2 months later. CONCLUSION: The mechanism of primary resistance to osimertinib remains unclear. There may be an association between T790 M mutation disappearance, TP53 mutation and radiotherapy, but further researches are needed to confirm this.

Recruitment of CD11b+Ly6C+ monocytes in non-small cell lung cancer xenografts challenged by anti-VEGF antibody.

A series of antibodies against vascular endothelial growth factor (VEGF) have been developed for the treatment of various types of cancer, including non-small cell lung cancer (NSCLC) in recent years. However, tumors frequently demonstrate resistance to these strategies of VEGF inhibition. Efforts to better understand the mechanism underlying the acquired resistance to anti-VEGF antibodies are warranted. In the present study, in order to develop a xenograft model of acquired resistance to anti-VEGF antibody, xenografts of human adenocarcinoma A549 cells were generated through the successive inoculation of tumor tissue explants into first (F1), second (F2) and third (F3) generations of mice treated with the anti-VEGF antibody B20. Tumor growth rate and vessel-forming ability, assessed via cluster of differentiation (CD) 31 staining, were significantly lower in the F1, F2 and F3 groups compared with in the F0 control group (P<0.01), suggesting that drug resistance was not successfully acquired. The percentages of CD11b+ myeloid-derived suppressor cells and lymphocyte antigen 6C (Ly6C)+ subsets were significantly smaller in F1, F2 and F3 groups compared with in F0 (P<0.01). However, the ratio of Ly6C+ to CD11b+ cells was significantly higher in the F3 group compared with in F0 and F1 groups (P<0.01), indicating increasing recruitment of the Ly6C+ subset with successive challenges with the anti-VEGF antibody. In conclusion, the recruitment of CD11b+Ly6C+ monocytes increased with successive generations of NSCLC-xenografted mice challenged by B20, an anti-VEGF agent.

Essential role of miR-200c in regulating self-renewal of breast cancer stem cells and their counterparts of mammary epithelium.

BACKGROUND: Breast cancer stem cells (BCSCs) have been reported as the origin of breast cancer and the radical cause of drug resistance, relapse and metastasis in breast cancer. BCSCs could be derived from mutated mammary epithelial stem cells (MaSCs). Therefore, comparing the molecular differences between BCSCs and MaSCs may clarify the mechanism underlying breast carcinogenesis and the targets for gene therapy. Specifically, the distinct miRNome data of BCSCs and MaSCs need to be analyzed to find out the key miRNAs and reveal their roles in regulating the stemness of BCSCs. METHODS: MUC1(-)ESA(+) cells were isolated from normal mammary epithelial cell line MCF-10A by fluorescence-activated cell sorting (FACS) and tested for stemness by clonogenic assay and multi-potential differentiation experiments. The miRNA profiles of MaSCs, BCSCs and breast cancer MCF-7 cells were compared to obtain the candidate miRNAs that may regulate breast tumorigenesis. An miRNA consecutively upregulated from MaSCs to BCSCs to MCF-7 cells, miR-200c, was chosen to determine its role in regulating the stemness of BCSCs and MaSCs in vitro and in vivo. Based on bioinformatics, the targets of miR-200c were validated by dual-luciferase report system, western blot and rescue experiments. RESULTS: In a 2-D clonogenic assay, MUC1(-)ESA(+) cells gave rise to multiple morphological colonies, including luminal colonies, myoepithelial colonies and mixed colonies. The clonogenic potential of MUC1(-)ESA(+) (61.5 ± 3.87 %) was significantly higher than that of non-stem MCF-10A cells (53.5 ± 3.42 %) (P < 0.05). In a 3-D matrigel culture, MUC1(-)ESA(+) cells grew into mammospheres with duct-like structures. A total of 12 miRNAs of interest were identified, 8 of which were upregulated and 4 downregulated in BCSCs compared with MaSCs. In gain- and lost-of-function assays, miR-200c was sufficient to inhibit the self-renewal of BCSCs and MaSCs in vitro and the growth of BCSCs in vivo. Furthermore, miR-200c negatively regulated programmed cell death 10 (PDCD10) in BCSCs and MaSCs. PDCD10 could rescue the tumorigenesis inhibited by miR-200c in BCSCs. DISCUSSION: Accumulating evidence shows that there is a milignant transformation from MaSCs into BCSCs. The underlying mechanism remains unclear. In present study, miRNA profiles between MaSCs and BCSCs were obtained. Then miRNA-200c, downregulated in both MaSCs and BCSCs, were verified as anti-oncogene, and played essential role in regulating self-renewal of both kinds of stem-like cells. These findings reveal a novel insights of breast tumorigenesis. CONCLUSIONS: PDCD10 is a target gene of miR-200c and also a possible mechanism by which miR-200c plays a role in regulating the stemness of BCSCs and MaSCs.

Regulation of miRNAs affects radiobiological response of lung cancer stem cells.

Radiotherapy (RT) is a key therapeutic strategy for lung cancer, the most common cause of cancer-related deaths worldwide, but radioresistance often occurs and leads to failure of RT. It is therefore important to clarify the mechanism underlying radioresistance in lung cancer. Cancer stem cells (CSCs) are considered the fundamental reason for radioresistance. MicroRNAs (miRNAs) have been regarded as important regulatory molecules of CSCs, carcinogenesis, and treatment response of cancers. It is crucial to clarify how regulation of miRNAs affects repair of DNA damage, redistribution, repopulation, reoxygenation, and radiosensitivity (5R) of lung cancer stem cells (LCSCs). A thorough understanding of the regulation of miRNAs affecting 5R of LCSCs has potential impact on identifying novel targets and thus may improve the efficacy of lung cancer radiotherapy.

Efficacy and safety of endostar® combined with chemotherapy in patients with advanced soft tissue sarcomas.

BACKGROUND: Soft tissue sarcomas (STS) are a heterogeneous group of tumors, and approximately 40-50% of patients with STS develop metastatic disease. The median overall survival of those patients was 12 months and their 5-year survival rate was 8%. Therefore, study on more effective treatment, especially the targeting therapies, is urgently needed. OBJECTIVE: To evaluate the efficacy and safety of Endostar® combined with chemotherapy in patients with advanced STS. METHODS: A retrospective case-series study was conducted in Cancer Institute of PLA, Xinqiao Hospital. A total of 71 patients suffering from advanced STS (IIB - IV) were included, of whom 49 cases treated with chemotherapy alone were defined as the control group and the rest 22 cases treated with the traditional chemotherapy combined with Endostar® were defined as the test group. The short-term therapeutic effects including objective response rate (ORR), disease control rate (DCR) and safety were evaluated in the two groups. In the follow-up, progression-free survival (PFS) and overall survival (OS) were also observed. RESULTS: In the test and control groups, the ORR was 18.2% and 12.2%, respectively (P = 0.767), and the DCR was 86.4% and 61.2%, respectively (P=0.034). The median time to progression in the test and control groups was 120 days and 70 days with significant difference (P = 0.017), while the median overall survival was 452 days and 286 days without significant difference (P = 0.503). The one-year survival rate in the test group and control group was 56.2% and 35.4%, respectively, while the two-year survival rate was 30.2% and 26.5%, respectively. No significant difference in the side effects was found between the two groups. CONCLUSIONS: Endostar® combined with chemotherapy resulted in a higher DCR and longer PFS in the patients with advanced STS, and the toxicity was tolerable.