DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Inhibition of Notch and HIF enhances the antitumor effect of radiation in Notch expressing lung cancer

Background: The Notch receptor plays an important role in various cell fate decisions during development and in cancer. We have previously reported that Notch3 is upregulated by radiation in non-small cell lung cancer (NSCLC) cell lines and that the Notch pathway inhibitor γ secretase inhibitor GSI (gamma-secretase inhibitor), when combined with radiation therapy, significantly suppressed the growth of lung cancer cells. However, little is known about the mechanism of Notch upregulation induced by radiation. Based on reports of Notch expression being activated through the hypoxia inducible factor 1 (HIF-1) under hypoxic conditions, we hypothesized that HIF-1 would be involved in radiation-induced Notch activation in NSCLC. Methods: Changes in HIF-1 and Notch expression in two Notch expressing NSCLC cells line after radiation treatment were examined using Western blotting. Notch expression was evaluated after the suppression of HIF-1α by small interfering RNA. The cytotoxic effect of YC-1, a HIF inhibitor, GSI and radiation was examined using the MTT assay in vitro and the xenograft model. Result: We found radiation-induced expression of HIF-1α protein at 2-6 h after treatment and upregulated expression of Notch3 protein at 24 h after treatment under hypoxic conditions. Specific suppression of HIF-1α expression downregulated the radiation-induced Notch3 activation, suggesting that the Notch pathway is activated though HIF-1α after radiation. An antitumor effect of YC-1 was evident under hypoxic conditions only when there was simultaneous radiation treatment. GSI and YC-1 had a synergistic antitumor effect in vitro, and the combination of GSI and YC-1 showed the greatest radiosensitivity in vivo. Conclusion: Radiation-induced upregulation of the Notch pathway and HIF-1α protein may be potential therapeutic targets for more effective radiation therapy

Spontaneous regression of small cell lung cancer combined with cancer associated retinopathy

Spontaneous regression (SR) is defined as the complete or partial disappearance of disease without anticancer treatments. We report a case of SR of small cell lung cancer (SCLC) combined with cancer associated retinopathy (CAR). A 65-year-old woman was admitted to our hospital to examine abnormal shadows of the lung with visual loss. She was diagnosed with SCLC associated with CAR. Subsequent chest X-ray and CT scan showed partial regression of both primary tumor and lymph node metastasis without anticancer treatment. Recoverin antigen was present on the tumor cells and anti-recoverin antibody was observed in the patient's serum. Activation of recoverin-specific antitumor cytotoxic T lymphocyte (CTL) was observed in this patient. SCLC was considered to reduce spontaneously by the activation of recoverin-specific antitumor CTL. To the best of our knowledge, this is the first report of SR in SCLC combined with CAR. (C) 2014 Elsevier Ireland Ltd. All rights reserved

Combined inhibition of EZH2 and histone deacetylases as a potential epigenetic therapy for non-small-cell lung cancer cells

Recent discoveries have revealed that human cancer involves aberrant epigenetic alterations. We and others have previously shown that the histone methyltransferase EZH2, the catalytic subunit of polycomb repressive complex 2 (PRC2), is frequently overexpressed in non-small-cell lung cancer (NSCLC) and that an EZH2 inhibitor, 3-deazaneplanocin A, inhibits the proliferation of NSCLC cells. Transcriptional silencing by EZH2 was recently shown to be required for the activity of histone deacetylases (HDACs) that interact with another PRC2 protein, EED. To develop a more effective epigenetic therapy for NSCLC, we determined the effects of co-treatment with 3-deazaneplanocin A and the HDAC inhibitor vorinostat (SAHA) in NSCLC cells. The co-treatment synergistically suppressed the proliferation of all tested NSCLC cell lines, regardless of their epidermal growth factor receptor (EGFR) status. The synergistic effect was associated with slightly decreased histone H3 lysine 27 trimethylation, modestly increased histone acetylation, and the depletion of EZH2 and other PRC2 proteins. The co-treatment resulted in an accumulation of p27Kip1, decrease in cyclin A, and increased apoptotic fraction in an additive/synergistic manner. Interestingly, the co-treatment strongly suppressed EGFR signaling, not only in EGFR-wild-type NSCLC cells, but also in EGFR-mutant cells, mainly through dephosphorylation of EGFR. Furthermore, the co-treatment suppressed the in vivo tumor growth of EGFR-mutant, EGFR-tyrosine kinase-resistant H1975 cells more effectively than did each agent alone, without visible toxicity. These results suggest that the combined pharmacological targeting of EZH2 and HDACs may provide more effective epigenetic therapeutics for NSCLC

Expression of Bim, Noxa, and Puma in non-small cell lung cancer

Background: The BH3-only members of the Bcl-2 protein family have been proposed to play a key role in the control of apoptosis and in the initiation of the apoptotic pathways. In this study, we evaluated the expression of Bim, Noxa, and Puma in non-small cell lung cancer (NSCLC). Methods: A total of 135 surgically resected NSCLCs were immunohistochemically assessed for Bim, Noxa, and Puma expression. The immunoscores were determined, and then its correlation with either the clinicopathological variables or the survival outcomes were analyzed. Results: Immunohistochemical reactivity for Bim, Noxa, and Puma was detected in the cytoplasm of the tumor cells. Bim expression was associated with several clinicopathological factors, including sex (p < 0.001), smoking habit (p = 0.03), pathological histology (p = 0.001), pathological T stage (p = 0.03), pathological disease stage (p = 0.02), and differentiation of tumor (p < 0.001). Multivariate logistic regression analysis showed a significant correlation between low Bim expression and squamous cell carcinoma (p = 0.04), in addition to a correlation between high Bim expression and well differentiated tumors (p = 0.02). Analysis of cellular biological expression demonstrated a link between low Bim expression and high Ki67. While Noxa expression was also shown to be correlated with both smoking habit (p = 0.02) and the pathological histology (p = 0.03), there was no strong association observed between the expression and the clinical features when they were examined by a multivariate logistic regression analysis. No correlations were noted between Puma expression and any of the variables. Our analyses also indicated that the expression levels of the BH3-only proteins were not pertinent to the survival outcome. Conclusions: The current analyses demonstrated that Bim expression in the NSCLCs was associated with both squamous cell carcinoma histology and tumor proliferation

Stereotactic body radiotherapy using gated radiotherapy with real-time tumor-tracking for stage I non-small cell lung cancer

Background: To clarify the clinical outcomes of two dose schedule of stereotactic body radiotherapy (SBRT) for stage I non-small cell lung cancer (NSCLC) using a real-time tumor-tracking radiation therapy (RTRT) system in single institution. Methods: Using a superposition algorithm, we administered 48 Gy in 4 fractions at the isocenter in 2005-2006 and 40 Gy in 4 fractions to the 95% volume of PTV in 2007-2010 with a treatment period of 4 to 7 days. Target volume margins were fixed irrespective of the tumor amplitude. Results: In total, 109 patients (79 T1N0M0 and 30 T2N0M0). With a median follow-up period of 25 months (range, 4 to 72 months), the 5-year local control rate (LC) was 78% and the 5-year overall survival rate (OS) was 64%. Grade 2, 3, 4, and 5 radiation pneumonitis (RP) was experienced by 15 (13.8%), 3 (2.8%), 0, and 0 patients, respectively. The mean lung dose (MLD) and the volume of lung receiving 20 Gy (V20) were significantly higher in patients with RP Grade 2/3 than in those with RP Grade 0/1 (MLD p = 0.002, V20 p = 0.003). There was no correlation between larger maximum amplitude of marker movement and larger PTV (r = 0.137), MLD (r = 0.046), or V20 (r = 0.158). Conclusions: SBRT using the RTRT system achieved LC and OS comparable to other SBRT studies with very low incidence of RP, which was consistent with the small MLD and V20 irrespective of tumor amplitude. For stage I NSCLC, SBRT using RTRT was suggested to be reliable and effective, especially for patients with large amplitude of tumor movement

Improvements of visual function and outer retinal morphology following spontaneous regression of cancer in anti-recoverin cancer-associated retinopathy

Purpose: To report an anti-recoverin antibody-positive cancer-associated retinopathy (anti-recoverin CAR) patient with remarkable improvements of visual function and outer retinal morphology following spontaneous regression of cancer. Observations: A 65-year-old woman with small cell lung carcinoma developed progressive, bilateral vision loss with diffuse loss of the ellipsoid zone at the macula on optical coherence tomography and marked reduced responses of a- and b-waves on electroretinography. Western blot analysis led to a diagnosis of anti-recoverin CAR. The visual function and outer retinal morphology gradually improved following spontaneous regression of the cancer and the initiation of systemic corticosteroid. Subsequent intermittent chemotherapy and continuation of corticosteroid maintained reduction of the cancer and prevented the recurrence of CAR, with preservation of improvements of the visual function and macular outer retinal morphology. Conclusions and importance: These results suggest that requirement for obtaining good visual prognosis in CAR patients is to make the cancer regress prior to falling into photoreceptor apotosis

The Peptide Nucleic Acid-Locked Nucleic Acid Polymerase Chain Reaction Clamp-Based Test for Epidermal Growth Factor Receptor Mutations in Bronchoscopic Cytological Specimens of Non-Small Cell Lung Cancer

Objectives: Cytological examination of samples obtained by bronchoscopy is a useful method for establishing the diagnosis of non-small cell lung cancer (NSCLC). However, the utility of a highly sensitive method for the detection of epidermal growth factor receptor (EGFR) mutation in the cytological specimens has not been fully evaluated. Methods: We retrospectively examined the efficacy of the peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp (PNA-LNA PCR clamp) method for detecting EGFR mutations in 122 bronchoscopic cytological specimens from NSCLC patients. Results: Overall, 41 specimens (33.6%) were positive for EGFR mutation. Twenty-nine (39.7%) of 73 specimens obtained by using endobronchial ultrasonography with a guide sheath, 7 (33.3%) of 21 specimens obtained under direct vision by using a conventional bronchoscope, 4 (36.4%) of 11 specimens obtained by using an ultrathin bronchoscope, and 1 (5.9%) of 17 specimens obtained by endobronchial ultrasound-guided transbronchial needle aspiration were positive for EGFR mutation. Furthermore, among 22 resected NSCLC cases, the EGFR mutation status obtained from bronchoscopic materials was consistent with the status obtained from surgical samples, with the exception of one case. Conclusion: The detection of EGFR mutation by subjecting bronchoscopic cytological specimens to a PNA-LNA PCR clamp assay proves useful

CD8+ tumor-infiltrating lymphocytes predict favorable prognosis in malignant pleural mesothelioma after resection

Defects in human leukocyte antigen (HLA) class I expression may allow tumor cells to escape immune recognition. T-cell infiltration is associated with a good prognosis in many cancers. However, the role of HLA class I expression and tumor-infiltrating lymphocytes (TILs) in malignant pleural mesothelioma (MPM) has not been fully analyzed. In the present study, we investigated the immune profiles and conducted outcome analyses of MPM patients. HLA class I expression and TILs (CD4+, CD8+, and NK cells) were detected by immunohistochemistry in a series of 44 MPM cases. To detect HLA class I expression, specimens were stained with the anti-pan HLA class I monoclonal antibody EMR8-5. The expression of HLA class I was positive in all patients. There was no case that showed negative HLA class I expression. The density of CD4+ and CD8+ TILs were strongly correlated (R = 0.76, p < 0.001). A high density of CD8+ TILs was a significantly better prognostic factor for the survival of patients with extrapleural pneumonectomy (p < 0.05). Multivariate analysis revealed that a high density of CD8+ TILs is an independent prognostic factor for patients who underwent extrapleural pneumonectomy. The presence of intratumoral CD8+ T cells was correlated with an improved clinical outcome, raising the possibility that CD8+ T cells might play a pivotal role in the anti-tumor immune response against MPMs. Thus, the stimulation of CD8+ lymphocytes might be an efficacious immunotherapy for MPM patients