The efficacy and safety of chemotherapy with or without anti-PD-1 for the first-line treatment of advanced urothelial carcinoma.

OBJECTIVE: To compare the efficacy and safety of first-line anti-PD-1 combined with chemotherapy versus chemotherapy alone in patients with advanced urothelial carcinoma (UC). METHOD: Patients with advanced UC who received first-line treatment of chemotherapy (n = 51, gemcitabine/paclitaxel [albumin-bound] combined with platinum) or immunochemotherapy (n = 50, PD-1 inhibitors plus chemotherapy) were enrolled. The efficacy and safety were analyzed between the two groups. RESULTS: This study included data from 101 patients, including 51 patients in the chemotherapy group and 50 patients in the immunochemotherapy group. The median progression-free survival of the immunochemotherapy group was significantly longer than that of the chemotherapy group (11.5 vs. 7.17 m, HR = 0.56, p = 0.009). The two groups' overall survival showed no significant difference (20.3 vs. 17.8 m, p = 0.204). The objective response rates and the disease control rates of the two groups were 38.0% versus 49.0% (p = 0.26) and 88.0% versus 80.4% (p = 0.29). The incidence of adverse reactions (AEs) in the immunochemotherapy group and chemotherapy group were 90.0% and 84.3% (p = 0.394), respectively, and the incidence of Grade III-IV AEs were 32.0% and 35.3% (p = 0.726), respectively. CONCLUSION: In the first-line treatment of patients with advanced UC, anti-PD-1 therapy combined with chemotherapy might have better efficacy than chemotherapy alone, and AEs are similar between the two groups.

The gut microbiota modulates responses to anti-PD-1 and chemotherapy combination therapy and related adverse events in patients with advanced solid tumors.

Background: Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1) have been widely used in treating different malignancies. Several studies have reported that the gut microbiota modulates the response and adverse events (AEs) to ICIs in melanoma, non-small cell lung cancer (NSCLC), renal cell cancer and hepatocellular carcinoma, but data on other cancer types and ICI combination therapy are limited. Methods: Stool samples were collected from patients with cancer who received anti-PD-1 and chemotherapy combination treatment and were analyzed by fecal metagenomic sequencing. The microbiota diversity and composition were compared between the responder (R) and non-responder (NR) groups and the AE vs. the non-AE (NAE) groups. In addition, associated functional genes and metabolic pathways were identified. Results: At baseline, the microbiota diversity of the groups was similar, but the genera Parabacteroides, Clostridia bacterium UC5.1_2F7, and Bifidobacterium dentium were enriched in the R group, whereas Bacteroides dorei and 11 species of Nocardia were enriched in the NR group. At 6 weeks, the beta diversity was significantly different between the R and NR groups. Further analysis found that 35 genera, such as Alipes, Parabacteroides, Phascolarctobacterium, Collinsella, Ruminiclostridium, Porphyromonas, and Butyricimonas and several genera of the Fibrobacteraceae family, were frequently distributed in the R group, whereas 17 genera, including Enterococcus, Lachnoclostridium, Hungatella, and Bilophila and several genera of the Pseudonocardiaceae and Beijerinckiaceae families, were more abundant in the NR group. A total of 66 and 52 Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs (KOs) were significantly enriched in the R and NR groups, respectively. In addition, pathway analysis revealed functional differences in the gut microbacteria in the R group, including the enrichment of anabolic pathways and DNA damage repair (DDR) pathways. Dynamic comparisons of the bacterial composition at baseline, 6 weeks, and 12 weeks showed that the abundance of Weissella significantly increased in the R group at 6 weeks and the abundance of Fusobacterium and Anaerotruncus significantly increased in the NR group at 12 weeks. Linear discriminant analysis effect size analysis indicated that bacteria of Bacteroidetes, especially Bacteroides, were enriched in the NAE group, whereas flora of Firmcutes, such as Faecalibacterium prausnitzii, Bacteroides fragilis, and Ruminococcus lactaris, were enriched in the AE group. Conclusion: Beta diversity and differences in the gut microbiota modulated AEs and the response to anti-PD-1 blockade combined with chemotherapy, by regulating related anabolic and DDR pathways. Dynamic changes in the intestinal microbiome may predict the efficacy of PD-1 inhibitor-based therapy.

Response Efficacy of PD-1 and PD-L1 Inhibitors in Clinical Trials: A Systematic Review and Meta-Analysis.

BACKGROUND: Immune checkpoint inhibitors targeting the PD-1/PD-L1 pathway have demonstrated promise in treating a variety of advanced cancers; however, little is known regarding their efficacy under various clinical situations, including different cancer types, treatment lines, drug combinations, and therapeutic regimens. METHODS: Published articles and conference abstracts (in English) in PubMed, Embase, the Cochrane Central Register, and Web of Science were searched up to February 10, 2020. The data were analyzed by the meta-analysis program in Stata. RESULTS: A total of 16,400 patients from 91 clinical trials were included in this meta-analysis. PD-1/PD-L1 inhibitors had a mean ORR of 19.56% (95% CI: 15.09-24.03), a median TTR of 2.05 months (m) (95%CI: 1.85-2.26), and a median DOR of 10.65 m (95%CI: 7.78-13.52). First-line treatment had a higher ORR (36.57% vs. 13.18%) but a shorter DOR (9.00 m vs. 13.42 m) compared to the second-line or subsequent treatment. Immunotherapy combined with chemotherapy (I+C) (46.81% [95%CI: 36.02-57.60]) had a statistically significant higher ORR compared to immunotherapy (I) (17.75% [95%CI: 14.47-21.03]) or immunotherapy combined with immunotherapy (I+O) (12.25% [95%CI: 1.56-22.94]), while I+C (8.09 m [95%CI: 6.86-9.32]) appeared to reduce the DOR compared to I (12.39 m [95%CI: 7.60-17.18]). PD-1 inhibitors were associated with better ORR (21.65% vs. 17.60%) and DOR (11.26 m vs. 10.03 m) compared to PD-L1 inhibitors. There were no significant differences in TTR under different situations. CONCLUSIONS: PD-1/PD-L1 inhibitors were promising immunotherapeutic agents to achieve satisfactory response efficacies with different cancer types, treatment lines, drug combinations, and therapeutic regimens. This comprehensive summary of the response efficacy of PD-1/PD-L1 inhibitors serves as a reference for clinicians to make evidence-based decisions.

The Synergistic Effect of PARP Inhibitors and Immune Checkpoint Inhibitors.

Poly (ADP-ribose) polymerase (PARP) inhibitors have demonstrated great promise for treating cancers with homologous recombination (HR) defects, such as germline BRCA1/2 mutation. Further studies suggest that PARP inhibitors (PARPi) can also exhibit efficacy in HR-competent cancers, by amplifying the DNA damage and inducing immunogenic cell death, and PARPi lead to increasing tumor neoantigen, upregulation of interferons and PD-L1, and modulation of the tumor microenvironment, which may facilitate a more profound antitumor immune response. Immune checkpoint inhibitors (ICIs) targeting PD-1/PD-L1 or CTLA-4 have achieved impressive success in the treatment of different malignancies. However, only a subset of populations derive clinical benefit, and the biomarkers and resistance mechanisms are not fully understood. Therefore, given that PARPi could potentiate the therapeutic effect of ICIs, PARPi combined with ICIs are becoming an alternative for patients who cannot benefit from ICI monotherapy. In this review, we focus on the mechanisms and immune role of PARPi and discuss the rationale and clinical studies of this combined regimen.

Efficacy and safety of anti-PD-1-based therapy in combination with PARP inhibitors for patients with advanced solid tumors in a real-world setting.

BACKGROUND: Rationale exists for combining immune checkpoint inhibitors and PARP inhibitors (PARPi), and results of clinical trials in ovarian cancer are promising, but data in other cancers are limited. METHOD: Efficacy and safety of PARPi/anti-PD-1 in advanced solid tumors were retrospectively analyzed. The efficacy measures included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS). RESULTS: This retrospective study included data from 40 patients. The ORR was 27.5% (95% CI, 13.0-42.0%), with a DCR of 85.0% (95% CI, 73.4-96.6%). Except four patients in first-line treatment (three with PR and one with SD), the ORR of ≥second-line treatment, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) was 22.2%, 23.1% and 28.6%, and the DCR was 83.3%, 84.6% and 71.4%, separately. The median PFS of all patients, ≥second-line treatment, NSCLC and SCLC was 4.6 m, 4.2 m, 4.5 m and 3.7 m. The median OS was 9.4 m, 11.4 m, 12.7 m and 5.4 m, respectively. Multivariable analysis revealed that BRCA1/2 mutation was positively correlated with ORR (P = 0.008), and LDH≥250U/L was negatively correlated with lowered DCR (P = 0.018), while lymphocyte number, ECOG and LDH significantly influenced both PFS and OS. We found that the possible resistant mechanisms were sarcomatous degeneration and secondary mutation, including BRCA2 truncation mutation, A2M, JAK1,T790M, KEAP1 and mTOR mutation. 37.5% patients had ≥grade 3 adverse events. CONCLUSION: PARPi/anti-PD-1 is an effective and tolerable method for patients with advanced solid tumors, and BRCA1/2 is a potential biomarker.

Anti-PD-1/L1 plus anti-angiogenesis therapy as second-line or later treatment in advanced lung adenocarcinoma.

PURPOSE: Anti-programmed cell death protein 1 or its ligand (anti-PD-1/L1) monotherapy has become the standard second-line treatment in advanced lung adenocarcinoma. However, the strategy treatment of anti-PD-1/L1 plus anti-angiogenesis therapy has not been evaluated. We conducted this retrospective study to assess the efficacy and safety of anti-PD-1/L1 plus anti-angiogenesis therapy in patients with advanced lung adenocarcinoma in the second-line or later setting. METHODS: Patients with advanced lung adenocarcinoma who received anti-PD-1/L1 plus anti-angiogenesis therapy or anti-PD-1/L1 monotherapy in the second-line or later treatment from March 2015 to May 2019 in PLA General Hospital were retrospectively analyzed. The progression-free survival (PFS), overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety were assessed. Multivariate analyses of PFS and OS were performed with Cox proportional hazard regression models. RESULTS: Seventy-four patients were included in our study. Twenty-five patients were treated with anti-PD-1/L1 plus anti-angiogenesis therapy, and forty-nine patients were treated with anti-PD-1/L1 monotherapy. The disease control rate (DCR) was higher in the anti-PD-1/L1 plus anti-angiogenesis group than in the anti-PD-1/L1 monotherapy group (92.0% vs. 46.9%, P = 0.0004). The median progression-free survival (PFS) was 5.1 months vs. 2.0 months (HR 0.551 [95% confidence interval 0.337-0.902], P = 0.002) and median overall survival (OS) was 14.3 months vs. 8.4 months (HR 0.549 [95% CI 0.305-0.990], P = 0.046), respectively. Multivariate Cox proportional hazard regression models showed that anti-PD-1/L1 plus anti-angiogenesis group had prolonged PFS (HR 0.541 [95% CI 0.298-0.981], P = 0.033). The incidences of grade 3/4 adverse events were 12% (3/25) in anti-PD-1/L1 plus anti-angiogenesis group and 6% (3/49) in anti-PD-1/L1 monotherapy group. CONCLUSION: Compared with anti-PD-1/L1 monotherapy, anti-PD-1/L1 plus anti-angiogenesis therapy could significantly improve the clinical response and bring longer PFS and OS in patients with advanced lung adenocarcinoma who had failed first-line or later treatment. Further prospective studies are needed to validate our findings.

Association of the Pretreatment Lung Immune Prognostic Index with Survival Outcomes in Advanced Hepatocellular Carcinoma Patients Treated with PD-1 Inhibitors.

PURPOSE: At present, there are no validated biomarkers that can predict whether patients with advanced hepatocellular carcinoma (aHCC) are likely to benefit from anti-PD-1 therapy. We aimed to determine whether lung immune prognostic index (LIPI) is associated with outcomes in patients with aHCC treated with PD-1 inhibitors. PATIENTS AND METHODS: Patients undergoing initial treatment with PD-1 inhibitors for aHCC at a single center from January 1, 2015 to August 31, 2019 were included. The patients were stratified according to pretreatment LIPI based on a derived neutrophils/(leukocytes minus neutrophils) ratio (dNLR) ≥ 3 and a lactate dehydrogenase (LDH) level ≥ the upper limit of normal (ULN). Kaplan-Meier analysis and the Log rank test were used to calculate and compare survival between good LIPI and intermediate/poor LIPI scores. The prognostic values of LIPI for survival and disease control rate were evaluated using Cox proportional hazard and logistic regression models, respectively. RESULTS: Of the 108 study patients, 53 (49%) had a good LIPI (dNLR < 3 and LDH normal) and 55 (51%) had intermediate/poor LIPI (dNLR ≥ 3 or/and LDH ≥ ULN). With a median follow-up of 12.4 months, intermediate/poor LIPI was independently associated with shorter overall survival (OS) (hazard ratio [HR] 4.00; 95% CI, 2.00-8.03) and progression-free survival (PFS) (HR 2.65; 95% CI, 1.61-4.37). The median OS for good and intermediate/poor LIPI was not reached and was 13.7 (95% CI, 8.2-19.1) months, respectively, and the median PFS was 10.9 (95% CI, 8.9-12.9) and 4.0 (95% CI, 2.2-5.8) months (both P < 0.001), respectively. CONCLUSION: Pretreatment LIPI combined with a dNLR ≥ 3 and/or LDH ≥ ULN is associated with poor outcomes in patients with aHCC treated with PD-1 inhibitors. Further validation in large, prospective studies are warranted.

Comparative effectiveness of pembrolizumab vs. nivolumab in patients with recurrent or advanced NSCLC.

The efficacies of pembrolizumab and nivolumab have never been directly compared in a real-world study. Therefore, we sought to retrospectively evaluate the objective response rate (ORR) and the progression-free survival (PFS) of patients with recurrent or advanced non-small cell lung cancer (NSCLC) in a real-world setting. This study included patients with recurrent or advanced NSCLC diagnosed between September 1, 2015 and August 31, 2019, who were treated with programmed cell death 1 (PD-1) inhibitors at the Cancer Center of the Chinese People's Liberation Army. PFS was estimated for each treatment group using Kaplan-Meier curves and log-rank tests. The multivariate analysis of PFS was performed with Cox proportional hazards regression models. A total of 255 patients with advanced or recurrent NSCLC treated with PD-1 inhibitors were identified. The ORR was significantly higher in the pembrolizumab group than in the nivolumab group, while PFS was not significantly different between the two groups. Subgroup analysis showed that the ORR was significantly higher for pembrolizumab than for nivolumab in patients in the first-line therapy subgroup and in those in the combination therapy as first-line therapy subgroup. Survival analysis of patients receiving combination therapy as second- or further-line therapy showed that nivolumab had better efficacy than pembrolizumab. However, the multivariate analysis revealed no significant difference in PFS between patients treated with pembrolizumab and those treated with nivolumab regardless of the subgroup. In our study, no significant difference in PFS was noted between patients treated with pembrolizumab and those treated with nivolumab in various clinical settings. This supports the current practice of choosing either pembrolizumab or nivolumab based on patient preferences.

Association of immune-related pneumonitis with the efficacy of PD-1/PD-L1 inhibitors in non-small cell lung cancer.

BACKGROUND: Cutaneous adverse events (AEs) have been positively associated with immune checkpoint inhibitor (ICI) efficacy in patients with melanoma, but little is known regarding the association between checkpoint inhibitor pneumonitis (CIP) and programmed cell death protein 1/programmed death ligand 1 (PD-1/PD-L1) inhibitor efficacy in non-small cell lung cancer (NSCLC). METHODS: A single-institution, retrospective medical record review of patients with advanced or recurrent NSCLC who were treated with PD-1/PD-L1 inhibitors between 1 September 2015 and 1 June 2019 was conducted. A total of 276 NSCLC patients with or without immune-related pneumonitis who received at least one dose of ICIs and had at least one follow-up visit were identified. Kaplan-Meier curves of the progression-free survival (PFS) of patients stratified according to immune-related pneumonitis development were evaluated with the log-rank test as a preplanned primary objective. Multivariate analysis of PFS was performed with Cox proportional hazard regression models. RESULTS: In the cohort of 276 patients, 42 patients developed CIP attributed to PD-1/PD-L1 inhibitors. Survival analysis showed that the overall response rate was significantly higher in patients with CIP than in those without CIP (61.90% versus 29.91%, respectively, p < 0.01), and that CIP development was significantly associated with increased PFS (45.80 weeks versus 21.15 weeks, respectively, p < 0.01). Additionally, 16-week landmark analysis produced the same results. Similarly, subgroup analysis of PD-1 inhibitor-treated, nivolumab-treated, and pembrolizumab-treated groups also revealed that CIP increased survival in NSCLC patients. Additionally, grade 1-2 pneumonitis showed an association with increased ICI efficacy in NSCLC; however, grade 3-4 pneumonitis did not. In addition, only two of the four pneumonitis radiological subtypes showed associations with increased ICI efficacy in NSCLC. CONCLUSION: CIP is associated with enhanced PD-1/PD-L1 inhibitor efficacy in NSCLC patients. Grade 1-2 pneumonitis and the radiological features of hypersensitivity and cryptogenic organizing pneumonia (COP) may be signs of enhanced ICI efficacy. However, further studies with larger numbers of patients and longer follow-up times are needed to validate our findings.

Tumor Mutation Burden as a Potential Biomarker for PD-1/PD-L1 Inhibition in Advanced Non-small Cell Lung Cancer.

BACKGROUND: Immunotherapy based on programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors has revolutionized the treatment of non-small cell lung cancer (NSCLC). Patients with high PD-L1 expression or DNA mismatch repair deficiency (dMMR)/microsatellite instability-high (MSI-H) cancer are reported to benefit from PD-1/PD-L1 inhibitors. However, additional biomarkers are needed, and whether tumor mutation burden (TMB) can be a robust biomarker or not is still controversial. OBJECTIVE: We conducted this study to assess TMB as a biomarker for PD-1/PD-L1 inhibitor treatment in advanced NSCLC patients in a real-world setting. PATIENTS AND METHODS: Chinese NSCLC patients who received a PD-1/PD-L1 inhibitor at the People's Liberation Army General Hospital and who had pathological tissues available for TMB were retrospectively analyzed. Demographic and clinical information were evaluated. Targeted next-generation sequencing (NGS) of the tumor tissue was performed. The relationship between TMB and clinical benefit was assessed. RESULTS: Thirty-four patients treated with PD-1/PD-L1 inhibitors between March 2015 and January 2019 were analyzed. The TMB was greater in patients with complete response (CR)/partial response (PR) versus stable disease (SD) versus progressive disease (PD) (median 11 vs. 9.7 vs. 4.2 mutations/megabase [Mb]; p = 0.049). The median progression-free survival was 10.6 months in the TMB-high group versus 3.9 months in the TMB-low group (cut-off value = 10 mutations/Mb) (hazard ratio [HR] 0.26 [95% confidence interval 0.12-0.57], p = 0.0007). The median overall survival was 21.0 months and 11.6 months (HR 0.37 [0.17-0.81], p = 0.0126) in the TMB-high group and the TMB-low group, respectively. The disease control rate was higher in the TMB-high group than in the TMB-low group (100% vs. 70%, p = 0.024). CONCLUSIONS: High TMB was associated with a better outcome in advanced NSCLC patients who received PD-1/PD-L1 inhibitors in China. Further studies are needed to confirm our findings.

Immune checkpoint inhibitors combined with chemotherapy for the treatment of advanced pancreatic cancer patients.

Immune checkpoint inhibitors (ICIs) represent a major breakthrough for cancer treatment. However, evidence regarding the use of ICIs in pancreatic cancer (PC) remained scarce. To assess the efficacy and safety of ICIs plus chemotherapy, patients with advanced PC were retrospectively recruited and were treated with either chemotherapy alone or chemotherapy plus ICIs. Patients previously treated with any agents targeting T-cell co-stimulation or checkpoint pathways were excluded. The primary outcome was overall survival (OS). The secondary outcomes were progression-free survival (PFS), overall response rate (ORR) and safety. In total, 58 patients were included (combination, n = 22; chemotherapy, n = 36). The combination group showed a significantly longer OS than the chemotherapy group [median, 18.1 vs 6.1 months, hazard ratio (HR) 0.46 (0.23-0.90), P = 0.021]. The median PFSs were 3.2 months in the combination group and 2.0 months in the chemotherapy group [HR 0.57 (0.32-0.99), P = 0.041]. The combination group and the chemotherapy group had similar ORRs (18.2% vs 19.4%, P = 0.906). All patients who achieved a partial response received a doublet chemotherapy regimen regardless of co-treatment with ICIs. Grade 3 or higher adverse events occurred in 31.8% of the patients in the combination group and in 16.9% of those receiving chemotherapy. Although the incidence of serious treatment-related adverse events was higher in the combination group than in the chemotherapy group, the difference was not significant (P = 0.183). Our findings suggest that the combination of ICIs with chemotherapy is both effective and tolerable for advanced PC. ICIs combined with a doublet chemotherapy regimen might be a preferable choice.

PLEKHM2-ALK: A novel fusion in small-cell lung cancer and durable response to ALK inhibitors.

OBJECTIVES: In non-small cell lung cancer (NSCLC), anaplastic lymphoma kinase (ALK) rearrangement identifies a subgroup of patients who are sensitive to ALK tyrosine kinase inhibitors (TKIs). ALK fusion is extremely rare in small-cell lung cancer (SCLC). To the best of our knowledge, only two cases of SCLC harboring ALK fusion mutation has been reported previously, both of whom carrying EML4-ALK fusion. There are no standard treatment options for SCLC patients with ALK fusion mutations. Herein, we described a rare case of ALK-rearranged SCLC responding to ALK inhibitors. MATERIALS AND METHODS: Immunohistochemistry (IHC) assay and next-generation sequencing (NGS) were performed on the biopsied tumor tissue. RESULTS: NGS detected a novel pleckstrin homology and RUN domain containing M2 (PLEKHM2)-ALK fusion, while the IHC analysis revealed an ALK-positive tumor. For extensive SCLC patients, median OS was about 8-13 months. The patient in this case had durable clinical benefit upon the treatment with ALK inhibitors, achieving an overall survival (OS) of more than 27 months. CONCLUSION: This case provides a meaningful reference for the treatment of SCLC patients with ALK fusion mutations. This case also provides valuable information on the response to ALK inhibitors of patients with PLEKHM2-ALK fusion and better understanding of ALK-TKI applications in the future. NGS may be used as a routine test to explore more treatment opportunities for tumor SCLC patients.

Anti-PD-1 therapy combined with chemotherapy in patients with advanced biliary tract cancer.

BACKGROUND: Evidence for the efficacy of immunotherapy in biliary tract cancer (BTC) is limited and unsatisfactory. METHODS: Chinese BTC patients receiving a PD-1 inhibitor with chemotherapy, PD-1 inhibitor monotherapy or chemotherapy alone were retrospectively analyzed. The primary outcome was overall survival (OS). The key secondary outcomes were progression-free survival (PFS) and safety. Patients previously treated with any agent targeting T cell costimulation or immune checkpoints were excluded. RESULTS: The study included 77 patients (a PD-1 inhibitor plus chemotherapy, n = 38; PD-1 inhibitor monotherapy, n = 20; chemotherapy alone, n = 19). The median OS was 14.9 months with a PD-1 inhibitor plus chemotherapy, significantly longer than the 4.1 months with PD-1 inhibitor monotherapy (HR 0.37, 95% CI 0.17-0.80, P = 0.001) and the 6.0 months with chemotherapy alone (HR 0.63, 95% CI 0.42-0.94, P = 0.011). The median PFS was 5.1 months with a PD-1 inhibitor plus chemotherapy, significantly longer than the 2.2 months with PD-1 inhibitor monotherapy (HR 0.59, 95% CI 0.31-1.10, P = 0.014) and the 2.4 months with chemotherapy alone (HR 0.61, 95% CI 0.45-0.83, P = 0.003). Grade 3 or 4 treatment-related adverse events were similar between the anti-PD-1 combination group and the chemotherapy alone group (34.2% and 36.8%, respectively). CONCLUSIONS: Anti-PD-1 therapy plus chemotherapy is an effective and tolerable approach for advanced BTC.

The PI3K/Akt/GSK-3ß/ROS/eIF2B pathway promotes breast cancer growth and metastasis via suppression of NK cell cytotoxicity and tumor cell susceptibility.

OBJECTIVE: To examine the effect of pSer9-GSK-3ß on breast cancer and to determine whether the underlying metabolic and immunological mechanism is associated with ROS/eIF2B and natural killer (NK) cells. METHODS: We employed TWS119 to inactivate GSK-3ß by phosphorylating Ser9 and explored its effect on breast cancer and NK cells. The expression of GSK-3ß, natural killer group 2 member D (NKG2D) ligands, eIF2B was quantified by PCR and Western blot. We measured intracellular reactive oxygen species (ROS) and mitochondrial ROS using DCFH-DA and MitoSOXTM probe, respectively, and conducted quantitative analysis of cellular respiration on 4T1 cells with mitochondrial respiratory chain complex I/III kits. RESULTS: Our investigation revealed that TWS119 downregulated NKG2D ligands (H60a and Rae1), suppressed the cytotoxicity of NK cells, and promoted the migration of 4T1 murine breast cancer cells. Nevertheless, LY290042, which attenuates p-GSK-3ß formation by inhibiting the PI3K/Akt pathway, reversed these effects. We also found that higher expression of pSer9-GSK-3ß induced higher levels of ROS, and observed that abnormality of mitochondrial respiratory chain complex I/III function induced the dysfunction of GSK-3ß-induced electron transport chain, naturally disturbing the ROS level. In addition, the expression of NOX3 and NOX4 was significantly up-regulated, which affected the generation of ROS and associated with the metastasis of breast cancer. Furthermore, we found that the expression of pSer535-eIF2B promoted the expression of NKG2D ligands (Mult-1 and Rae1) following by expression of pSer9-GSK-3ß and generation of ROS. CONCLUSIONS: The PI3K/Akt/GSK-3ß/ROS/eIF2B pathway could regulate NK cell activity and sensitivity of tumor cells to NK cells, which resulted in breast cancer growth and lung metastasis. Thus, GSK-3ß is a promising target of anti-tumor therapy.

Methylglyoxal: A newly detected and potentially harmful metabolite in the blood of ketotic dairy cows.

Ketosis causes serious economic losses for the modern dairy industry because it is a highly prevalent metabolic disease among cows in high-producing herds during the transition period. Due to some striking similarities between diabetes in humans and ketosis in dairy cows, there is potential for the use of methylglyoxal (MGO)-commonly used in human diabetics-as a biomarker in dairy cattle. However, currently no data are available about the presence of MGO in the serum of dairy cattle or about the characteristics of its production or its potential contribution in the pathogenesis of ketosis. To determine the potential origin and pathway of formation of MGO, cows in different metabolic conditions [i.e., non-subclinically ketotic dairy cows in early lactation (n = 7), subclinically ketotic dairy cows in early lactation (n = 8), overconditioned dry cows (BCS >4.25, n = 6), and nonlactating heifers (n = 6)] were selected. Serum MGO concentrations were determined and correlated with indicators of the glucose and lipid metabolism and with haptoglobin (Hp) as an inflammatory marker. The serum MGO concentrations in subclinically ketotic cows (712.60 ± 278.77 nmol/L) were significantly greater than in nonlactating heifers (113.35 ± 38.90 nmol/L), overconditioned dry cows (259.71 ± 117.97 nmol/L), and non-subclinically ketotic cows (347.83 ± 63.56 nmol/L). In serum of lactating cows, concentrations of glucose and fructosamine were lower than in heifers and were negatively correlated with MGO concentrations. Even so, concentrations of metabolic and inflammatory markers such as dihydroxyacetone phosphate, nonesterified fatty acids, ß-hydroxybutyrate, acetone, and Hp were remarkably higher in subclinically ketotic cows compared with nonlactating heifers; these metabolites were also positively correlated with MGO. In human diabetics elevated MGO concentrations are stated to originate from both hyperglycemia and the enhanced lipid metabolism, whereas higher MGO concentrations in subclinically ketotic cows were not associated with hyperglycemia. Therefore, our data suggest MGO in dairy cows to be a metabolite produced from the metabolization of acetone within the lipid metabolization pathway and from the metabolization of dihydroxyacetone phosphate. Furthermore, the highly positive correlation between MGO and Hp suggests that this reactive compound might be involved in the proinflammatory state of subclinical ketosis in dairy cows. However, more research is needed to determine the potential use of MGO as a biomarker for metabolic failure in dairy cows.

Downregulation of MCT4 for lactate exchange promotes the cytotoxicity of NK cells in breast carcinoma.

Monocarboxylate transporter-4 (MCT4), a monocarboxylic acid transporter, demonstrates significantly increased expression in the majority of malignancies. We performed an experiment using BALB/C mice, and our results showed that ShMCT4 transfection or the pharmaceutic inhibition of MCT4 with 7acc1 strengthens the activity of NK cells. The results of a calcein assay revealed that the cytotoxicity of NK cells was strengthened via inhibition of MCT4. In addition, ELISA testing showed that the content of perforin and CD107a was increased, and PCR amplification and immunoblotting revealed that the expression of NKG2D and H60 was upregulated after the inhibition of MCT4. Further, we observed an elevated pH value, decreased extracellular lactate flow, and attenuated tumor growth. Therefore, we concluded that the inhibition of MCT4 enhanced the cytotoxicity of NK cells by blocking lactate flux and reversing the acidified tumor microenvironment. In addition to these findings, we also discovered that MCT4 depletion may have a pronounced impact on autophagy, which was surmised by observing that the inhibition of autophagy (3MA) pulled the enhanced cytotoxicity of NK cells downwards. Together, these data suggest that the key effect of MCT4 depletion on NK cells probably utilizes inductive autophagy as a compensatory metabolic mechanism to minimize the acidic extracellular microenvironment associated with lactate export in tumors.

Inhibition of Methylglyoxal-Induced Histone H1 Nε-Carboxymethyllysine Formation by (+)-Catechin.

Reactive dicarbonyl species (RCS) such as methylglyoxal (MGO) and glyoxal (GO) are common intermediates in protein damage, leading to the formation of advanced glycation end products (AGEs) through nonenzymatic glycation. (+)-Catechin, a natural plant extract from tea, has been evaluated for its ability in trapping GO and MGO. However, (+)-catechin is also reported to have both antioxidant ability and pro-oxidant properties. Until now, whether (+)-catechin can inhibit the formation of nonenzymatic glycation and the mechanism of the inhibition in nucleoprotein nonenzymatic glycation is still unclear. In the present study, histone H1 and MGO were used to establish an in vitro (100 mM phosphate buffer solution (PBS), pH 7.4, 37 °C) protein glycation model to study the trapping ability of (+)-catechin. Our data show that MGO caused dose-dependent protein damage, and the content of MGO-induced Schiff base formation was inhibited by (+)-catechin when the molecular ratio of catechin:MGO was 1:6. The formation of Nε-carboxymethyllysine (CML) was reduced significantly when the ratio of (+)-catechin and MGO was 1:1, which was similar to the inhibition effect of aminoguanidine (AG). The formation of CML under in vitro conditions can be inhibited by low concentration (12.5-100 µM) of (+)-catechin but not with high concentration (200-800 µM) of (+)-catechin. The reason is that the high concentration of (+)-catechin did not inhibit CML formations due to H2O2 produced by (+)-catechin. In the presence of catalase, catechin can inhibit MGO-induced CML formation. In conclusion, the trapping ability of (+)-catechin may be more effective at the early stage of nonenzymatic glycation. However, a high concentration (200-800 µM) of (+)-catechin may not inhibit the formation of CML because it induced the increase of H2O2 formation.

PTEN inhibits macrophage polarization from M1 to M2 through CCL2 and VEGF-A reduction and NHERF-1 synergism.

PTEN has been studied in several tumor models as a tumor suppressor. In this study, we explored the role of PTEN in the inhibition state of polarized M2 subtype of macrophage in tumor microenvironment (TME) and the underlying mechanisms. To elucidate the potential effect in TME, RAW 264.7 macrophages and 4T1 mouse breast cancer cells were co-cultured to reconstruct tumor microenvironment. After PTEN was down-regulated with shRNA, the expression of CCL2 and VEGF-A, which are definited to promote the formation of M2 macrophages, have a dramatically increase on the level of both gene and protein in co-cultured RAW 264.7 macrophages. And at the same time, NHERF-1 (Na(+)/H(+) exchanger regulating factor-1), another tumor suppressor has a similar tendency to PTEN. Q-PCR and WB results suggested that PTEN and NHERF-1 were consistent with one another no matter at mRNA or protein level when exposed to the same stimulus. Coimmunoprecipitation and immunofluorescence techniques confirmed that PTEN and NHERF-1 were coprecipitated, and NHERF-1 protein expression was properly reduced with rCCL2 effect. In addition, cell immunofluorescence images revealed a profound transferance, in co-cultured RAW 264.7 macrophages, an up-regulation of NHERF-1 could promote the PTEN marked expression on the cell membrane, and this form for the interaction was not negligible. These observations illustrate PTEN with a certain synergy of NHERF-1, as well as down-regulation of CCL2 suppressing M2 macrophage transformation pathway. The results suggest that the activation of PTEN and NHERF-1 may impede the evolution of macrophages beyond the M1 into M2 phenotype in tumor microenvironment.

Colorimetric and luminescent bifunctional Ru(II) complex-modified gold nano probe for sensing of DNA.

A colorimetric and luminescent bifunctional Ru(II) complex-modified gold nano-probe for sensing ctDNA was developed. A new water-soluble Ru(II) complex containing an aromatic α-diimine ligand with an extended π system was found to be emissive at about 588nm in water and the emission intensity of the complex was enhanced about 3.4-fold upon addition of calf thymus DNA (ctDNA) in aqueous buffer with no color changes. The detection limit was 70nM with a 1.2% relative standard deviation (RSD, n=5). The Ru(II) complex chromophore was used to modify 8nm MHA carboxylate-functionalized gold nanoparticles to produce a colorimetric and luminescent bifunctional probe for sensing ctDNA in aqueous buffer at room temperature. The obvious change in visible color and enhancement of emission intensity of the functionalized gold-Ru(II) complex colloids upon addition of ctDNA was due to the electron or energy transfer between Ru(II) chromophore and the Au-NPs. The limit of detection was 1.0nM for ctDNA with a 4.5% RSD (n=5). With such a high sensitivity, the bifunctional Ru(II) complex-modified gold nano-probe will be potentially suitable for the DNA sensing in bioanalytical application.