Appropriate delay of primary tumour radiotherapy may lead to better long-term overall survival for non-small cell lung cancer treated with EGFR-TKIs.

PURPOSE: The most appropriate time of primary tumor radiotherapy in non-small cell lung cancer(NSCLC) with EGFR-TKIs remains unclear. The aim of this study was to investigate the effect of the time factor of primary tumor radiotherapy on long-term overall survival(OS)and provide a theoretical basis for further clinical research. PATIENTS AND METHODS: In total, 238 patients with EGFR-TKIs and OS ≥ 12 months were statistically analysed. Patients were grouped: the D group without primary tumor radiotherapy and the R group with it.The R group were divided into three groups according to the interval between the start of EGFR-TKIs and the start of primary tumor radiotherapy: R0 - 30(<30 days), R30 - PD(≥ 30 days and disease stable), and RPD(radiotherapy after disease progression). The Kaplan-Meier method and log-rank test were used for survival analyses. Exploratory landmark analyses were investigated. RESULTS: The OS rates at 1, 2, 3, 5 years for the R group and D group were 96.8%, 62.9%, 38.3%, 17.1%, and 95.6%, 37.7%, 21.8%, 2.9%, respectively; the corresponding MST was 29 months(95% CI: 24.3-33.7) for the R group and 22 months(95% CI: 20.4-23.6) for the D group (χ2 = 13.480, p<0.001). Multivariate analysis revealed that primary tumor radiotherapy was independent predictors of prolonged OS.Among the four groups, The R30 - PD appeared to have the best OS (D, χ2 = 19.307, p<0.001;R0 - 30, χ2 = 11.687, p = 0.01; RPD, χ2 = 4.086, p = 0.043). Landmark analyses(22 months) showed the R30 - PD group had a significant long-term OS.The incidence of radiation pneumonitis ≥ grade 2 was17.3%(n = 19)and radiation esophagitis ≥ grade 2 was observed in 32 patients(29.1%). CONCLUSIONS: Our results showed that primary tumour radiotherapy may prolong long-term OS with acceptable toxicities. Appropriate delay(R30 - PD)of primary tumour radiotherapy may be the best choice.Premature radiotherapy(R0 - 30) and radiotherapy after disease progression (RPD)may not be reasonable for long-term OS.

Molecular recognition of ITIM/ITSM domains with SHP2 and their allosteric effect.

Src homology 2-domain-containing tyrosine phosphatase 2 (SHP2) is a non-receptor protein tyrosine phosphatase that is widely expressed in a variety of cells and regulates the immune response of T cells through the PD-1 pathway. However, the activation mechanism and allosteric effects of SHP2 remain unclear, hindering the development of small molecule inhibitors. For the first time, in this study, the complex structure formed by the intact PD-1 tail and SHP2 was modeled. The molecular recognition and conformational changes of inactive/active SHP2 versus ITIM/ITSM were compared based on prolonged MD simulations. The relative flexibility of the two SH2 domains during MD simulations contributes to the recruitment of ITIM/ITSM and supports the subsequent conformational change of SHP2. The binding free energy calculation shows that inactive SHP2 has a higher affinity for ITIM/ITSM than active SHP2, mainly because the former's N-SH2 refers to the α-state. In addition, a significant decrease in the contribution to the binding energy of certain residues (e.g., R32, S34, K35, T42, and K55) of conformationally transformed SHP2 contributes to the above result. These detailed changes during conformational transition will provide theoretical guidance for the molecular design of subsequent novel anticancer drugs.

Design, synthesis and bioevaluation of dual EGFR-PI3Kα inhibitors for potential treatment of NSCLC.

Aberrant activation or mutation of the EGFR-PI3K-Akt-mTOR signaling pathway has been implicated in a wide range of human cancers, especially non-small-cell lung cancer (NSCLC). Thus, dual inhibition of EGFR and PI3K has been investigated as a promising strategy to address acquired drug resistance resulting from the use of tyrosine kinase inhibitors. A series of dual EGFR/PI3Kα inhibitors was synthesized using pharmacophore hybridization of the third-generation EGFR inhibitor olmutinib and the PI3Kα selective inhibitor TAK-117. The optimal compound 30k showed potent kinase inhibitory activities with IC50 values of 3.6 and 30.0 nM against EGFRL858R/T790M and PI3Kα, respectively. Compound 30k exhibited a significant antiproliferative effect in NCI-H1975 cells with a higher selectivity profile than olmutinib. The potential antitumor mechanism, molecular binding modes, and in vitro metabolic stability of compound 30k were also clarified.

Response of TCE biodegradation to elevated H2 and O2: Implication for electrokinetic-enhanced bioremediation.

The study investigated the influences of pure H2 and O2 introduction, simulating gases produced from the electrokinetic-enhanced bioremediation (EK-Bio), on TCE degradation, and the dynamic changes of the indigenous microbial communities. The dissolved hydrogen (DH) and oxygen (DO) concentrations ranged from 0.2 to 0.7 mg/L and 2.6 to 6.6 mg/L, respectively. The biological analysis was conducted by 16S rRNA sequencing and functional gene analyses. The results showed that the H2 introduction enhanced TCE degradation, causing a 90.4% TCE removal in the first 4 weeks, and 131.1 µM was reduced eventually. Accordingly, cis-dichloroethylene (cis-DCE) was produced as the only product. The following three ways should be responsible for this promoted TCE degradation. Firstly, the high DH rapidly reduced the oxidation-reduction potential (ORP) value to around -500 mV, beneficial to TCE microbial dechlorination. Secondly, the high DH significantly changed the community and promoted the enrichment of TCE anaerobic dechlorinators, such as Sulfuricurvum, Sulfurospirillum, Shewanella, Geobacter, and Desulfitobacterium, and increased the abundance of dechlorination gene pceA. Thirdly, the high DH promoted preferential TCE dechlorination and subsequent sulfate reduction. However, TCE bio-remediation did not occur in a high DO environment due to the reduced aerobic function or lack of functional bacteria or co-metabolic substrate. The competitive dissolved organic carbon (DOC) consumption and unfriendly microbe-microbe interactions also interpreted the non-degradation of TCE in the high DO environment. These results provided evidence for the mechanism of EK-Bio. Providing anaerobic obligate dechlorinators, and aerobic metabolic bacteria around the electrochemical cathodes and anodes, respectively, or co-metabolic substrates to the anode can be feasible methods to promote remediation of TCE-contaminated shallow aquifer under EK-Bio technology.

Identification of novel PD-1/PD-L1 small molecule inhibitors: virtual screening, synthesis and in vitro characterisation.

The PD-1/PD-L1 pathway is considered as one of the most promising immune checkpoints in tumour immunotherapy. However, researchers are faced with the inherent limitations of antibodies, driving them to pursue PD-L1 small molecule inhibitors. Virtual screening followed by experimental validation is a proven approach to discover active compounds. In this study, we employed multistage virtual screening methods to screen multiple compound databases to predict new PD-1/PD-L1 ligands. 35 compounds were proposed by combined analysis of fitness scores, interaction pattern and MM-GBSA binding affinities. Enzymatic assay confirmed that 10 out of 35 ligands were potential PD-L1 inhibitors, with inhibitory rate higher than 50% at the concentration of 30 µM. Among them, ZDS20 was identified as the most effective inhibitor with low micromolar activity (IC50 = 3.27 µM). Altogether, ZDS20 carrying novel scaffold was identified and could serve as a lead for the development of new classes of PD-L1 inhibitors.

Preliminary results of randomized phase II study of etoposide plus lobaplatin or etoposide plus cisplatin with concurrent thoracic radiotherapy in the treatment of limited-stage small cell lung cancer.

The purpose is to compare the clinical efficacy and toxicity of etoposide plus lobaplatin (EL) or etoposide plus cisplatin (EP) with concurrent thoracic radiotherapy during the treatment of limited-stage small cell lung cancer (LS-SCLC). Forty-two patients with LS-SCLC were randomly divided into EL ( n = 19) or EP ( n = 23) regimens combined with thoracic intensity-modulated radiotherapy. The primary endpoint was 1-year progression-free survival (PFS) rate. The 1-, 2-, and 3-year PFS rates in the EL and EP cohorts were 50.8, 38.1, and 12.7%; and 56.5, 43.5, and 29.0%, respectively ( P = 0.527), whereas the 1-, 2-, and 3-year overall survival (OS) rates were 72.2, 52.5, and 43.8%; and 73.9, 48.4, and 48.4%, respectively ( P = 0.923). The hematological toxicities were similar in two cohorts. However, gastrointestinal reactions were more severe in the EP group. The incidence of nausea and vomiting in EL and EP cohorts were 31.6% vs. 73.9% ( P = 0.006) and 20.1% vs. 60.9% ( P = 0.009), respectively. The two cohorts did not show ≥grade 4 radiation esophagitis and ≥grade 3 radiation pneumonitis. The incidence of acute radiation esophagitis in EL group was lower ( P = 0.038), both groups showed a similar incidence of radiation pneumonitis ( P = 1.000). EL or EP chemotherapy with concurrent thoracic radiotherapy showed similar PFS and OS. The EL group showed milder gastrointestinal toxicity and radiation esophagitis. Radiation pneumonitis and hematological toxicity were similar in the two regimens, which can be tolerated by patients.

Study on the allosteric activation mechanism of SHP2 via elastic network models and neural relational inference molecular dynamics simulation.

As a ubiquitous protein tyrosine phosphatase, SHP2 is involved in PD-1/PD-L1 mediated tumor immune escape and undergoes substantial conformational changes. Therefore, it is considered an ideal target for tumor intervention. However, the allosteric mechanisms of SHP2 binding PD-1 intracellular ITIM/ITSM phosphopeptides remain unclear, which greatly hinders the development of novel structure-based anticancer allosteric inhibitors. In this work, the open and closed structural models of SHP2 are first constructed based on this knowledge; next their motion modes are investigated via elastic network models such as the Gaussian network model (GNM), anisotropic network model (ANM) and adaptive anisotropic network model (aANM); and finally, a possible allosteric signaling pathway is proposed using a neural relational inference molecular dynamics (NRI-MD) simulation embedded with an artificial intelligence (AI) strategy. In GNM and ANM, the N-SH2, C-SH2 and PTP domains all exhibit distinct dynamics partitions, and the N-SH2/C-SH2 regions show a rigid rotation relative to PTP. According to a series of intermediate snapshots given by aANM, N-SH2 is first identified with pY223 specifically, inducing a D'E-loop to change from ß-sheets to random coils, and then, C-SH2 serves as a fulcrum to drive N-SH2 to rotate 110° completely away from the original active sites of PTP. Finally, a possible allosteric signaling-transfer path for SHP2, namely R220-R138-T108-R32, is proposed based on NRI-MD sampling. This work provides a possible allosteric mechanism of SHP2, which is helpful for the following design of novel allosteric inhibitors and is expected to be used in clinical synergies with PD-1 monoclonal antibody.

Recombinant human endostatin combined with radiotherapy promotes cardiomyocyte apoptosis in rats via TGFß1/Smads/CTGF signaling pathway.

PURPOSE: The aim of the present study was to investigate the efficacy of recombinant human endostatin (ES) (rh-ES) combined with radiation on rat cardiomyocyte apoptosis and the regulatory mechanism of transforming growth factor beta1 (TGF-ß1)/Sma and Mad-related protein 3 (Smad3)/connective tissue growth factor (CTGF) signaling. METHOD: The primary cardiomyocytes were isolated from neonatal Sprague-Dawley rats for culture in vitro and divided into blank control group (without treatment), 10 Gy radiation + siTGF-ß1 siRNA (gene silencing) group, ES + siTGF-ß1 siRNA group, and 10 Gy radiation + ES + siTGF-ß1 siRNA group. Methyl thiazolyl tetrazolium assay was used to calculate the half-maximal inhibitory concentration (IC50) of rh-ES on cardiomyocytes. Adenoviral vector was constructed for virus packaging to silence TGF-ß1 expression in cardiomyocytes. Quantitative real-time polymerase chain reaction and Western blot were carried out to analyze TGF-ß1, Smad2, Smad3 and CTGF expression at both gene and protein levels. Flow cytometry and electron microscope were used to examine cell apoptosis. RESULTS: ES had a dose-dependent inhibitory effect on the proliferation of primary rat cardiomyocytes. ES combined with radiotherapy significantly inhibited cardiomyocyte proliferation and promoted cell apoptosis (P < 0.01). The gene and protein expression of TGF-ß1, Smad2, Smad3 and CTGF were significantly up-regulated in primary cardiomyocytes transfected with TGF-ß1 gene (P < 0.05). CONCLUSION: The combination therapy with rh-ES and radiation can promote cardiomyocyte apoptosis and aggravate myocardial cell damage via TGF-ß1/Smad3/CTGF signaling pathway.

Reovirus enhances cytotoxicity of natural killer cells against colorectal cancer via TLR3 pathway.

BACKGROUND: Cetuximab has been approved for use for first-line treatment of patients with wild-type KRAS metastatic colorectal cancer (CRC). However, treatment with cetuximab has shown limited efficacy as a CRC monotherapy. In addition, natural killer (NK) cell function is known to be severely attenuated in cancer patients. The goal of this study was to develop a new strategy to enhance antibody-dependent cell-mediated cytotoxicity (ADCC) mediated by NK cells, in combination with cetuximab against CRC cells. METHODS: Ex vivo expanded NK cells were stimulated with reovirus, and reovirus-activated NK cells mediated ADCC assay were performed on CRC cells in combination with cetuximab. The synergistic antitumor effects of reovirus-activated NK cells and cetuximab were tested on DLD-1 tumor-bearing mice. Finally, Toll-like receptor 3 (TLR3) knockdown in NK cells, along with chemical blockade of TLR3/dsRNA complex, and inhibition of the TLR3 downstream signaling pathway, were performed to explore the mechanisms by which reovirus enhances NK cell cytotoxicity. RESULTS: We first confirmed that exposure of NK cells to reovirus enhanced their cytotoxicity in a dose-dependent manner.We then investigated whether reovirus-activated NK cells exposed to cetuximab-bound CRC cells exhibited greater anti-tumor efficacy than either monotherapy. Co-culture of CRC cell lines with reovirus-activated NK cells indicated that NK cytotoxicity was significantly higher in combination with cetuximab, regardless of KRAS mutation status or EGFR expression level. We also found that reovirus activation of NK cells, in conjunction with cetuximab, resulted in significantly stronger anti-tumor efficacy.Finally, TLR3 knockdown, inhibition of TLR3/dsRNA complex or TBK1/IKKε demonstrated that activation of NK cells by reovirus was dependent on TLR3 and its downstream signaling pathway. CONCLUSIONS: This study demonstrated that combination treatment of reovirus-activated NK cells with cetuximab synergistically enhances their anti-tumor cytotoxicity, suggesting a strong candidate strategy for clinical treatment of CRC.

Pemetrexed plus cisplatin versus docetaxel plus cisplatin for stage IV lung adenocarcinoma based on propensity score matching.

The aim of this study was to compare the clinical efficacy of pemetrexed+cisplatin (PP) versus docetaxel+cisplatin (DP) for the treatment of stage IV lung adenocarcinoma. We retrospectively analyzed the clinical data of 147 patients with stage IV lung adenocarcinoma treated between January 2011 and December 2015, 100 of which were in the DP group whereas 47 were in the DP group. Main inclusion criteria were treatment-naive patients, first-line treatment with PP or DP with no molecular targeted therapy during treatment, 2-6 cycles of first-line chemotherapy with unknown status of epidermal growth factor receptor (EGFR) mutation, 18-75 years of age, and Karnofsky performance status score of at least 70. Prognostic factors for survival were identified by using univariate and multivariate analyses. Propensity score matching was performed to further adjust for confounding. A total of 47 pairs were successfully matched between the two groups. The median overall survival was 9.0 months in the DP group and 17.0 months in the PP group; the 1-year survival rate was 29.8 and 59.6%, respectively; the 2-year survival rate was 12.8 and 21.1%, respectively (χ=4.128, P=0.042); and median progression-free survival was 6.0 and 8.0 months, respectively (χ=4.839, P=0.028). Cox multivariate analysis showed that chemotherapy regimen and number of metastatic organs were independent factors for OS. The effect of the radiotherapy dose on the primary tumor on OS was close to statistically significant. The incidence of grade 3-4 neutropenia was more significantly reduced in the DP group than in the PP group after matching (61.7 vs. 27.7%, P=0.002), with no between-group difference for adverse effects on platelets or hemoglobin. For patients with stage IV lung adenocarcinoma and unknown EGFR mutation status, PP was more effective than DP in prolonging survival and had a less adverse effect on neutrophils.