Tumor immune microenvironment of NSCLC with EGFR exon 20 insertions may predict efficacy of first-line ICI-combined regimen.

OBJECTIVES: Non-small cell lung cancer (NSCLC) patients with exon 20 insertion mutations (ex20ins) of the epidermal growth factor receptor (EGFR) were resistant to monotherapy of immune checkpoint inhibitor (ICI). However, recent reports have shown that the combination of ICI and chemotherapy (ICI-combined regimen) exhibited certain efficacy for NSCLC with EGFR ex20ins. The mechanisms behind this phenomenon have not been thoroughly clarified. Hence, we conducted this study tofind correlations between the tumor immune microenvironment of EGFR ex20ins and the efficacy of ICI-combined regimen. METHODS: We performed single-cell transcriptome sequencing and multiplex immunofluorescence staining (mIF) to investigate the immune microenvironment of NSCLC patients with EGFR ex20ins, L858R, and EGFR wild-type. We analyzed 15 treatment-naïve NSCLC samples utilizing single-cell RNA sequencing (scRNA-seq). Another 30 cases of EGFR L858R and 4 cases of wild-type were recruited to compare the immune microenvironment with that of EGFR ex20ins (28 cases) by mIF. RESULTS: We observed that cell components, function and interactions varied between EGFR ex20ins, L858R, and wild-type NSCLC.We discovered similar T cell and CD8+ T cell distributions among groups but found noninferior or even better T cell activation in ex20ins patients. Infiltrating CD8+ FOXP3- T cells were significantly lower in the tumor region of EGFR ex20ins compared to wild-type. T cells from the ex20ins group had a greater tendency to promote cancer cell inflammation and epithelial-mesenchymal transition (EMT) compared to wild-type group. For macrophages, there were more M2-like macrophages in ex20ins patients. M1-like macrophages in ex20ins group produced fewer antitumor cytokines than in other groups. CONCLUSIONS: The immune microenvironment of EGFR ex20ins is more suppressive than that of L858R and wild-type, suggesting that ICI monotherapy may not be sufficient for these patients. ICI-combined regimen might be a treatment option for EGFR ex20ins due to tumor-promoting inflammation and noninferior T cell functions in the immune microenvironment.

LILRB2/PirB mediates macrophage recruitment in fibrogenesis of nonalcoholic steatohepatitis.

Inhibition of immunocyte infiltration and activation has been suggested to effectively ameliorate nonalcoholic steatohepatitis (NASH). Paired immunoglobulin-like receptor B (PirB) and its human ortholog receptor, leukocyte immunoglobulin-like receptor B (LILRB2), are immune-inhibitory receptors. However, their role in NASH pathogenesis is still unclear. Here, we demonstrate that PirB/LILRB2 regulates the migration of macrophages during NASH by binding with its ligand angiopoietin-like protein 8 (ANGPTL8). Hepatocyte-specific ANGPTL8 knockout reduces MDM infiltration and resolves lipid accumulation and fibrosis progression in the livers of NASH mice. In addition, PirB-/- bone marrow (BM) chimeras abrogate ANGPTL8-induced MDM migration to the liver. And yet, PirB ectodomain protein could ameliorate NASH by sequestering ANGPTL8. Furthermore, LILRB2-ANGPTL8 binding-promoted MDM migration and inflammatory activation are also observed in human peripheral blood monocytes. Taken together, our findings reveal the role of PirB/LILRB2 in NASH pathogenesis and identify PirB/LILRB2-ANGPTL8 signaling as a potential target for the management or treatment of NASH.

Mutational landscape of DNA damage response deficiency-related genes and its association with immune biomarkers in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) has limited effective treatment strategies. DNA damage response (DDR) genes are of therapeutic interest in multiple cancer types. This study aimed to depict the landscape of DDR mutations in ESCC and evaluate the association between DDR mutations and known immunotherapy biomarkers. We recruited 250 Chinese patients with ESCC and performed next-generation sequencing. A total of 107 patients underwent a PD-L1 examination. Among the 250 patients, 73 (29.2%) harbored at least one DDR gene mutation and were defined as DDR-mut. Among the six functional DDR pathways, homologous recombination (HR) accounted for 12.4% (31/250). DDR-mut patients were significantly associated with higher tumor mutational burden than those in the DDR-wt group (p=7.4e-07). Patients with PDL1-H accounted for 21.2% (36/107) of the patients. PDL1-H was more prevalent in DDR-mut than DDR-wt, although the p-value did not reach a significant level (40.5% vs. 30%, p=0.29). Further analysis revealed that BRCA1, one of the most frequently mutated genes in the HR pathway, was significantly associated with PDL1-H (p=0.01). Our data revealed a subset of patients with ESCC harbored DDR gene mutations. Patients with these DDR gene mutations are significantly associated with immune biomarkers, implying the potential feasibility of combining DDR agents with immunotherapy in patients with DDR deficiency.

Retinol dehydrogenase 10 promotes metastasis of glioma cells via the transforming growth factor-ß/SMAD signaling pathway.

BACKGROUND: Glioma is the most common primary malignant tumor in the central nervous system. Because of the resistance of glioma to chemoradiotherapy and its aggressive growth, the survival rate of patients with glioma has not improved. This study aimed to disclose the effect of retinol dehydrogenase 10 (RDH10) on the migration and invasion of glioma cells, and to explore the potential mechanism. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the expression levels of RDH10 in healthy glial cells and glioma cells. Human glioma cell strains, U87 and U251, were infected with negative control or RDH10-interfering lentiviruses. RT-PCR and Western blotting were performed to determine the knockdown efficiency. Scratch and transwell assays were used to assess cell migration and invasion after RDH10 knockdown. Finally, changes in transforming growth factor-ß (TGF-ß)/SMAD signaling pathway-related expression were examined by Western blotting. Differences between groups were analyzed by one-way analysis of variance. RESULTS: RDH10 was highly expressed in glioma cells. Compared with the control group, RDH10 knockdown significantly reduced RDH10 messenger RNA and protein expression levels in U87 and U251 glioma cells (U87: 1.00 ±â€Š0.08 vs. 0.22 ±â€Š0.02, t = 16.55, P < 0.001; U251: 1.00 ±â€Š0.17 vs. 0.39 ±â€Š0.01, t = 6.30, P < 0.001). The scratch assay indicated that compared with the control group, RDH10 knockdown significantly inhibited the migration of glioma cells (U87: 1.00% ±â€Š0.04% vs. 2.00% ±â€Š0.25%, t = 6.08, P < 0.01; U251: 1.00% ±â€Š0.11% vs. 2.48% ±â€Š0.31%, t = 5.79, P < 0.01). Furthermore, RDH10 knockdown significantly inhibited the invasive capacity of glioma cells (U87: 97.30 ±â€Š7.01 vs. 13.70 ±â€Š0.58, t = 20.36, P < 0.001; U251: 96.20 ±â€Š7.10 vs. 18.30 ±â€Š2.08, t = 18.51, P < 0.001). Finally, Western blotting demonstrated that compared with the control group, downregulation of RDH10 significantly inhibited TGF-ß expression, phosphorylated SMAD2, and phosphorylated SMAD3 (TGF-ß: 1.00 ±â€Š0.10 vs. 0.53 ±â€Š0.06, t = 7.05, P < 0.01; phosphorylated SMAD2: 1.00 ±â€Š0.20 vs. 0.42 ±â€Š0.17, t = 4.01, P < 0.01; phosphorylated SMAD3: 1.00 ±â€Š0.18 vs. 0.41 ±â€Š0.12, t = 4.12, P < 0.01). CONCLUSION: RDH10 knockdown might inhibit metastasis of glioma cells via the TGF-ß/SMAD signaling pathway.

Application of neuroendoscopic surgical techniques in the assessment and treatment of cerebral ventricular infection.

Cerebral ventricular infection (CVI) is one of the most dangerous complications in neurosurgery because of its high mortality and disability rates. Few studies have examined the application of neuroendoscopic surgical techniques (NESTs) to assess and treat CVI. This multicenter, retrospective study was conducted using clinical data of 32 patients with CVI who were assessed and treated by NESTs in China. The patients included 20 men and 12 women with a mean age of 42.97 years. NESTs were used to obliterate intraventricular debris and pus, fenestrate or incise the intraventricular compartment and reconstruct cerebrospinal fluid circulation, and remove artificial material. Intraventricular irrigation with antibiotic saline was applied after neuroendoscopic surgery (NES). Secondary hydrocephalus was treated by endoscopic third ventriculostomy or a ventriculoperitoneal shunt. Neuroendoscopic findings of CVI were used to classify patients into Grade I (n = 3), Grade II (n = 13), Grade III (n = 10), and Grade IV (n = 6) CVI. The three patients with grade I CVI underwent one NES, the 23 patients with grade II/III CVI underwent two NESs, and patients with grade IV CVI underwent two (n = 3) or three (n = 3) NESs. The imaging features and grades of neuroendoscopy results were positively related to the number of neurosurgical endoscopic procedures. Two patients died of multiple organ failure and the other 30 patients fully recovered. Among the 26 patients with secondary hydrocephalus, 18 received ventriculoperitoneal shunt and 8 underwent endoscopic third ventriculostomy. There were no recurrences of CVI during the 6- to 76-month follow-up after NES. Application of NESTs is an innovative method to assess and treat CVI, and its neuroendoscopic classification provides an objective, comprehensive assessment of CVI. The study trial was approved by the Institutional Review Board of Beijing Shijitan Hospital, Capital Medical University, China.

KLF7 promotes polyamine biosynthesis and glioma development through transcriptionally activating ASL.

Krüppel-like factors (KLFs) are zinc-finger transcriptional factors that regulate target gene expression. Recent studies have shown that KLFs play essential roles in cancer development, whereas the function of KLF7 in glioma remains unclear. In this study, we showed that KLF7 was up-regulated in glioma tissues and its expression was inversely correlated with the patients' survival. Functional experiments demonstrated that KLF7 promoted the proliferation, migration and tumorigenesis of glioma cells. Mechanistically, KLF7 transcriptionally activated argininosuccinate lyase (ASL), which was observed highly expressed in glioma tissues. The biosynthesis of polyamine, a urea cycle metabolite, was enhanced by KLF7 in glioma cells. In addition, ASL contributed to the growth of glioma cells triggered by KLF7. Our findings demonstrate KLF7 as an oncogene and link KLF7 to ASL-mediated polyamine metabolism in glioma.

Hippo/YAP signaling pathway is involved in osteosarcoma chemoresistance.

BACKGROUND: Osteosarcoma is the most common bone malignancy in children and adolescents, and 20%-30% of the patients suffer from poor prognosis because of individual chemoresistance. The Hippo/yes-associated protein (YAP) signaling pathway has been shown to play a role in tumor chemoresistance, but no previous report has focused on its involvement in osteosarcoma chemoresistance. This study aimed to investigate the role of the Hippo/YAP signaling pathway in osteosarcoma chemoresistance and to determine potential treatment targets. METHODS: Using the Cell Titer-Glo Luminescent cell viability assay and flow cytometry analysis, we determined the proliferation and chemosensitivity of YAP-overexpressing and YAP-knockdown osteosarcoma cells. In addition, using western blotting and the real-time polymerase chain reaction technique, we investigated the alteration of the Hippo/YAP signaling pathway in osteosarcoma cells treated with chemotherapeutic agents. RESULTS: Mammalian sterile 20-like kinase 1 (MST1) degradation was increased, and large tumor suppressor kinase 1/2 (LATS1/2) total protein levels were decreased by methotrexate and doxorubicin, which increased activation and nuclear translocation of YAP. Moreover, YAP increased the proliferation and chemoresistance of MG63 cells. CONCLUSIONS: The Hippo/YAP signaling pathway plays a role in osteosarcoma chemoresistance, and YAP is a potential target for reducing chemoresistance.

Synthesis and biological evaluation of quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at C2-position as potential antitumor agents.

A series of quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at the C2-position were synthesized and evaluated for their antiproliferative activities against A549, MCF-7, HeLa, HT29 and HCT-116 cell lines. Most of the synthesized compounds exhibited broad spectrum antitproliferative activity against five cell lines, of which 5c was the most potent against HT29 cell line with an IC50 value of 5.53 µM, inducing a G2/M phase arrest in HT29 cells. Treatment of HT29 cells with 5c resulted in BubR1 phosphorylation and an increase of mitotic index in a time-dependent manner. Furthermore, 5c promoted tubulin polymerization in vitro. These results demonstrate that quinazolin-4(3H)-one derivatives bearing dithiocarbamate side chain at C2-position may be potentially novel antitumor agents targeting tubulin to activate the spindle assembly checkpoint.