Detailed mechanism study of volatile organic compound decomposition and oxidation removal based on a ReaxFF MD method.

Volatile organic compounds (VOCs) are typical air pollutants as well as gaseous wastes that contain energy. Utilization and disposition of VOCs is currently an important research hotspot in the field of atmospheric environment. In this paper, the thermal cracking and oxidation reaction processes of typical VOCs components were modelled and analyzed by combining molecular dynamics and detailed reaction mechanisms, focusing on the effects of temperature, oxygen and other conditions on the conversion of VOCs. The results of molecular dynamics studies show that improving temperature and reaction time benefit the decomposition of VOCs. High temperatures under an inert atmosphere can sufficiently crack the VOCs themselves, but other by-products are generated, which in turn cause secondary pollution. The activation energies derived by ReaxFF-MD calculation are 328 kJ mol-1, 147 kJ mol-1 and 121 kJ mol-1 for toluene, styrene and benzaldehyde respectively, which is consistent with experimental results. Under the oxygen atmosphere, the conversion rate of VOCs is greatly increased and the reaction temperature is significantly reduced. Meanwhile, the oxidation reaction fully converts VOCs into non-polluting products such as CO2 and H2O. Detailed kinetic studies show that initial oxidation of toluene molecules raised by hydrogen abstraction reaction is the dominant step during toluene oxidation, which significantly improved the decomposition efficiency of toluene.

Serine/Threonine Kinase (STK) 33 promotes the proliferation and metastasis of human esophageal squamous cell carcinoma via inflammation-related pathway.

The serine/threonine kinase (STK) 33 plays a key role in cancer cell proliferation and metastasis. Abnormal STK33 expression is closely related to malignancy of numerous cancers. This study suggests the important role of STK33 in the pathogenesis and metastatic progression of esophageal squamous cell carcinoma (ESCC). STK33 expression in human ESCC tissues was detected by immunohistochemical technique. Further, we analyzed the relationship between STK33 and clinical and pathological factors as well as the prognosis of patients. ECa109 cell line was cultured and transfected with STK33-RNAi lentiviral vector to perform Hochest33342 & PI and metastasis experiments. The TCGA database was used to analyze the STK33 expression level in ESCC. All statistical analyses were performed in SPSS 23.0 software. Differences with P < 0.05 were considered statistically significant. In human ESCC specimens, STK33 was overexpressed and associated with poor prognosis. Silencing STK33 expression suppressed ESCC proliferation, migration, invasion, and tumor growth. STK33 also mediated angiogenesis, TGFß, and inflammatory response in ESCC. Mechanistic investigations revealed that STK33 regulates ESCC through multiple complex pathways. Dysregulated STK33 signaling promotes ESCC growth and progression. Thus, our findings identified STK33 as a candidate treatment target that improves ESCC therapy.

CCDC66 mutations are associated with high myopia through affected cell mitosis.

BACKGROUND: High myopia (HM) refers to an eye refractive error exceeding -5.00 D, significantly elevating blindness risk. The underlying mechanism of HM remains elusive. Given the extensive genetic heterogeneity and vast genetic base opacity, it is imperative to identify more causative genes and explore their pathogenic roles in HM. METHODS: We employed exome sequencing to pinpoint the causal gene in an HM family. Sanger sequencing was used to confirm and analyse the gene mutations in this family and 200 sporadic HM cases. Single-cell RNA sequencing was conducted to evaluate the gene's expression patterns in developing human and mouse retinas. The CRISPR/Cas9 system facilitated the gene knockout cells, aiding in the exploration of the gene's function and its mutations. Immunofluorescent staining and immunoblot techniques were applied to monitor the functional shifts of the gene mutations at the cellular level. RESULTS: A suspected nonsense mutation (c.C172T, p.Q58X) in CCDC66 was found to be co-segregated with the HM phenotype in the family. Additionally, six other rare variants were identified among the 200 sporadic patients. CCDC66 was consistently expressed in the embryonic retinas of both humans and mice. Notably, in CCDC66-deficient HEK293 cells, there was a decline in cell proliferation, microtube polymerisation rate and ace-tubulin level. Furthermore, the mutated CCDC66 failed to synchronise with the tubulin system during Hela cell mitosis, unlike its wild type counterpart. CONCLUSIONS: Our research indicates that the CCDC66 variant c.C172T is associated with HM. A deficiency in CCDC66 might disrupt cell proliferation by influencing the mitotic process during retinal growth, leading to HM.

Responses of a common tropical epiphyte, Asplenium nidus, to changes in water and nutrient availability.

Epiphytes are highly dependent on atmospheric inputs of water and nutrients. Reductions in water availability associated with warming and climate change and continual atmospheric nitrogen (N) deposition can affect plant growth but few studies have evaluated the effects of changes in both water and nutrient availabilities on epiphytes. We experimentally tested whether epiphyte growth is more water- or nutrient-limited, if nutrient limitation was stronger for nitrogen or phosphorus, and whether nutrient limitation interacts with water availability. We applied watering (high and low) and nutrient addition (control, +N, +P, +N+P) treatments to greenhouse-grown Asplenium nidus, a common epiphytic fern found in many tropical and subtropical wet forests. We measured leaf area production and leaf elemental concentrations to assess how A. nidus growth and physiology respond to changes in water and nutrient availabilities. We found that leaf growth of A. nidus was more affected by water availability than nutrient addition and the effect of adding nutrients was not fully realized under low-water availability. Among the different nutrient treatments, +N+P had the greatest effects on A. nidus growth and physiology in both watering treatments. Watering treatment changed leaf elemental concentrations but not their ratios (i.e. C:N and N:P). Nutrient addition altered C:N and N:P ratios and increased the concentration of the added elements in leaves, with more pronounced increases in the high-watering treatment. We conclude that the growth of A. nidus is more water- than nutrient-limited. When nutrient limitation occurs (i.e. under high-water availability), nutrient co-limitation is stronger than limitation by N or P alone. This result taken together with studies of other epiphytes suggests greater water than nutrient limitation is likely widespread among epiphytic plants. The limited effects of nutrient addition in the low-water treatment suggest that the effect of atmospheric N deposition on epiphyte growth will be limited when water availability is low.

The use of D-dimer in the diagnosis and risk assessment of intracardiac thrombus among patients with dilated cardiomyopathy.

D-dimer is a biomarker of coagulation and fibrinolytic system activation in response to the body's hypercoagulable state. The study aims to investigate the usefulness of D-dimer in diagnosing and assessing the risk of intracardiac thrombus in patients with dilated cardiomyopathy (DCM). Consecutively enrolled in this study were patients with DCM who were admitted to our center for the first time. The diagnostic value was evaluated using the receiver operating characteristic (ROC) curve. Additionally, we used univariate and multivariate logistic regression to investigate the association between D-dimer and intracardiac thrombus. We also performed smooth curve fitting, threshold saturation effect analysis, and subgroup analysis. In total, 534 patients were enrolled in the study, and among them, 65 patients had intracardiac thrombus. Mural thrombus was the predominant type of thrombus, which was mainly located in the left ventricular apex. The optimal cut-off value of D-dimer for the diagnosis of intracardiac thrombus was 484 ng/mL, with a sensitivity and specificity of 0.769 and 0.646, respectively. In both unadjusted and adjusted logistic regression models, a positive association was found between D-dimer and intracardiac thrombus. Curve fitting and threshold effect analysis revealed two inflection points in the relationship between D-dimer and intracardiac thrombus (non-linear test: P = 0.032). When D-dimer was equal to 362 ng/mL, the odds ratio (OR) was 1, and the risk of thrombus gradually increased until it reached 4096 ng/mL, after which the trend no longer increased. Within this range, a twofold increase in D-dimer was associated with a 103.2% increased risk (OR = 2.032; 95% CI 1.293-3.193; P < 0.01). In the subgroup analysis, there was a significant interaction between D-dimer and BMI on intracardiac thrombus (P value for interaction was 0.013), and the risk was higher in patients with a BMI ≥ 25 kg/m2 (OR = 3.44; 95% CI 1.86-6.36; P < 0.01).

ALKBH5 promotes hypopharyngeal squamous cell carcinoma apoptosis by targeting TLR2 in a YTHDF1/IGF2BP2-mediated manner.

Hypopharyngeal squamous cell carcinoma (HPSCC) is one of the most aggressive cancers and is notorious for its extremely poor prognosis. However, very few molecular biological studies have been performed. As a novel method of epigenetic gene modulation, N6-methyladenosine (m6A) RNA modification occurs in HPSCC. The expression of the m6A demethylase AlkB homolog 5 (ALKBH5) is frequently downregulated in human HPSCC. Furthermore, we found that ALKBH5 impaired cell proliferation by regulating human Toll-like receptor 2 (TLR2) in an m6A-dependent manner in HPSCC cells. ALKBH5 decreased TLR2 m6A modification, which could be recognized by the m6A readers IGF2BP2 and YTHDF1. IGF2BP2 facilitates TLR2 mRNA stability, whereas YTHDF1 promotes TLR2 mRNA translation. The current work uncovered a critical function of ALKBH5 in TLR2 regulation and provides a novel role for m6A demethylation of mRNA in HPSCC. The inhibition of m6A modification of ALKBH5 in HPSCC deserves further clinical investigation.

Two-year impact of COVID-19 pandemic on hospitalized patients with skin diseases in China.

To investigate the clinical characteristics of skin disorders among hospitalized patients before and during the coronavirus disease 2019 (COVID-19) pandemic, a retrospective study was conducted based on hospitalized patients with skin diseases from Xiangya Hospital of Central South University, the largest hospital in the south-central region of China, between January 1, 2018, and December 31, 2021. A total of 3039 hospitalized patients were enrolled in the study, including 1681 patients in the prepandemic group and 1358 patients in the pandemic group. The total number of hospitalized patients in the pandemic group decreased by 19.2%, with an increased proportion of patients over 60 years of age (39.8% vs. 35.8%). Moreover, compared with the prepandemic group, there were decreases in the occurrence of most skin diseases in the pandemic group, but the proportions of keratinolytic carcinoma (6.6% vs. 5.2%), dermatitis (24.0% vs. 18.9%), and psoriasis (18.0% vs. 14.8%) were higher in the pandemic group. In addition, longer hospital stays (ß = 0.07, SE = 0.02, P = 1.35 × 10-3 ) and higher hospital costs (ß = 0.06, SE = 0.03, p = 0.031) were found in the pandemic group through general linear models, even after the corresponding adjustment. In summary, the COVID-19 pandemic has had a lasting impact on patients with skin diseases, with fewer hospitalized patients, increased proportions of older patients, longer hospital stays, and increased hospital costs. These findings will facilitate better preparation for the most effective response to future pandemics.

DPred_3S: identifying dihydrouridine (D) modification on three species epitranscriptome based on multiple sequence-derived features.

Introduction: Dihydrouridine (D) is a conserved modification of tRNA among all three life domains. D modification enhances the flexibility of a single nucleotide base in the spatial structure and is disease- and evolution-associated. Recent studies have also suggested the presence of dihydrouridine on mRNA. Methods: To identify D in epitranscriptome, we provided a prediction framework named "DPred_3S" based on the machine learning approach for three species D epitranscriptome, which used epitranscriptome sequencing data as training data for the first time. Results: The optimal features were evaluated by the F-score and integration of different features; our model achieved area under the receiver operating characteristic curve (AUROC) scores 0.955, 0.946, and 0.905 for Saccharomyces cerevisiae, Escherichia coli, and Schizosaccharomyces pombe, respectively. The performances of different machine learning algorithms were also compared in this study. Discussion: The high performances of our model suggest the D sites can be distinguished based on their surrounding sequence, but the lower performance of cross-species prediction may be limited by technique preferences.

Prognostic potential of liver injury in patients with dilated cardiomyopathy: a retrospective study.

BACKGROUND: Liver injury (LI) has been frequently observed in patients with dilated cardiomyopathy (DCM), whereas its prognostic value remains blurry. We attempted to appraise the prognostic effect of LI in patients with DCM. METHODS: This retrospective study included 523 patients with DCM. LI was defined as a threefold increase in aspartate transaminase (≥ 135 U/L) or alanine transaminase (≥ 180 U/L) or a twofold increase in total bilirubin (≥ 41 umol/L) during hospitalization. The population was segmented into non-liver injury (NLI) group and LI group based on liver function test data. To balance differences in covariates at baseline, 1:1 propensity score matching (PSM) was performed. RESULTS: Patients with LI had lower survival rate, compared with those with NLI (44.6% vs. 73.8%, P < 0.001). Similar results were also found in age (age > 50, 39.6% vs. 70.9%, P < 0.001; age ≤ 50, 51.3% vs. 79.5%, P < 0.001) and gender stratified analysis (male, 46.2% vs. 74.4%, P < 0.001; female 35.7% vs. 72.0%, P = 0.001). After PSM, the survival rate of patients with LI remained lower than those with NLI (44.6% vs. 64.1%, P = 0.019). Multivariable Cox regression analysis manifested that LI (hazard ratio [HR]: 1.692, 95% confidence interval [CI] 1.194-2.398, P = 0.003; HR: 1.675, 95% CI 1.078-2.604, P = 0.022, respectively) showed potent predictive effect on all-cause mortality in patients with DCM, both before and after PSM. CONCLUSIONS: The occurrence of LI herald adverse outcomes in patients with DCM and attention to LI may be conducive to risk stratification and management.

Sonidegib Suppresses Production of Inflammatory Mediators and Cell Migration in BV2 Microglial Cells and Mice Treated with Lipopolysaccharide via JNK and NF-κB Inhibition.

Our structure-based virtual screening of the FDA-approved drug library has revealed that sonidegib, a smoothened antagonist clinically used to treat basal cell carcinoma, is a potential c-Jun N-terminal kinase 3 (JNK3) inhibitor. This study investigated the binding of sonidegib to JNK3 via 19F NMR and its inhibitory effect on JNK phosphorylation in BV2 cells. Pharmacological properties of sonidegib to exert anti-inflammatory and anti-migratory effects were also characterized. We found that sonidegib bound to the ATP binding site of JNK3 and inhibited JNK phosphorylation in BV2 cells, confirming our virtual screening results. Sonidegib also inhibited the phosphorylation of MKK4 and c-Jun, the upstream and downstream signals of JNK, respectively. It reduced the lipopolysaccharide (LPS)-induced production of pro-inflammatory factors, including interleukin-1ß (IL-1ß), IL-6, tumor necrosis factor-α (TNF-α), and nitric oxide (NO), and the expression of inducible NO synthase and cyclooxygenase-2. The LPS-induced cell migration was suppressed by sonidegib. Sonidegib inhibited the LPS-induced IκBα phosphorylation, thereby blocking NF-κB nuclear translocation. Consistent with these findings, orally administered sonidegib attenuated IL-6 and TNF-α levels in the brains of LPS-treated mice. Collectively, our results indicate that sonidegib suppresses inflammation and cell migration in LPS-treated BV2 cells and mice by inhibiting JNK and NF-κB signaling. Therefore, sonidegib may be implicated for drug repurposing to alleviate neuroinflammation associated with microglial activation.

Identification of a prognostic model using cuproptosis-related genes in uveal melanoma.

The most common intraocular malignancy in adults remains uveal melanoma (UVM), and those with metastatic disease have a poor outlook. Proliferation, angiogenesis, and metastasis of tumor cells can be triggered by cuproptosis, affecting the survival of cancer patients. Nonetheless, cuproptosis-related genes (CRGs) have not been identified in UVM. In this study, we analyzed 10 CRGs in 80 patients with UVM in the Cancer Genome Atlas (TCGA) database regarding the alterations of the genes including copy number variation and methylation. We further constructed a prognostic gene model using these CRGs and built the risk score formula. Univariate and multivariate Cox regression was applied to validate the risk score as an independent prognostic factor. The prognostic model was validated using 63 UVM samples from the GSE22138 cohort, an independent validation data set. Based on the risk scores for 80 patients with UVM from TCGA, we categorized the patients into high- and low-risk groups. Differentially expressed genes (DEGs) between groups were enriched in allograft rejection, hypoxia, glycolysis, TNFα signaling via NF-κB, and interferon-γ responses via Gene set enrichment analysis (GSEA). CD8 T cells and exhausted T cells were notably enriched in the high-risk group. In conclusion, the alteration of CRGs is related to patients with UVM, and the constructed CRG-related model may be helpful to predict the prognosis of such patients.

Chemotherapy reinforces anti-tumor immune response and enhances clinical efficacy of immune checkpoint inhibitors.

New evidence suggests that the clinical success of chemotherapy is not merely due to tumor cell toxicity but also arises from the restoration of immunosurveillance, which has been immensely neglected in previous preclinical and clinical researches. There is an urgent need for novel insights into molecular mechanisms and regimens that uplift the efficacy of immunotherapy since only a minority of cancer patients are responsive to immune checkpoint inhibitors (ICIs). Recent findings on combination therapy of chemotherapy and ICIs have shown promising results. This strategy increases tumor recognition and elimination by the host immune system while reducing immunosuppression by the tumor microenvironment. Currently, several preclinical studies are investigating molecular mechanisms that give rise to the immunomodulation by chemotherapeutic agents and exploit them in combination therapy with ICIs in order to achieve a synergistic clinical activity. In this review, we summarize studies that exhibit the capacity of conventional chemotherapeutics to elicit anti-tumor immune responses, thereby facilitating anti-tumor activities of the ICIs. In conclusion, combining chemotherapeutics with ICIs appears to be a promising approach for improving cancer treatment outcomes.

Single-cell RNA sequencing depicts the local cell landscape in thyroid-associated ophthalmopathy.

There is a specific reactivity and characteristic remodeling of the periocular tissue in thyroid-associated ophthalmopathy (TAO). However, local cell changes responsible for these pathological processes have not been sufficiently identified. Here, single-cell RNA sequencing is performed to characterize the transcriptional changes of cellular components in the orbital connective tissue in individuals with TAO. Our study shows that lipofibroblasts with RASD1 expression are highly involved in inflammation and adipogenesis during TAO. ACKR1+ endothelial cells and adipose tissue macrophages may engage in TAO pathogenesis. We find CD8+CD57+ cytotoxic T lymphocytes with the terminal differentiation phenotype to be another source of interferon-γ, a molecule actively engaging in TAO pathogenesis. Cell-cell communication analysis reveals increased activity of CXCL8/ACKR1 and TNFSF4/TNFRSF4 interactions in TAO. This study provides a comprehensive local cell landscape of TAO and may be valuable for future therapy investigation.

Use of Lactiplantibacillus plantarum ZJ316 as a starter culture for nitrite degradation, foodborne pathogens inhibition and microbial community modulation in pickled mustard fermentation.

The potential of Lactiplantibacillus plantarum ZJ316 (ZJ316) as a starter culture for quality improvement and microbial community regulation in pickled mustard fermentation was elucidated in this study. Our results show that ZJ316 can deter the occurrence of nitrite peaks and maintain the nitrite content of pickled mustard at a low level (0.34 mg/kg). The headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry results indicate that ZJ316 gives a good flavor to pickled mustard. According to the 16S rDNA results, Firmicutes were the predominant microbiota after inoculation with ZJ316, and the abundances of Citrobacter, Enterobacter, and Proteus decreased simultaneously. In addition, antibacterial activity analysis showed that the supernatant of pickled mustard inoculated with ZJ316 had a significant inhibitory effect on Staphylococcus aureus D48, Escherichia coli DH5α, and Listeria monocytogenes LM1. In conclusion, L. plantarum ZJ316 has potential for use as an ideal starter in the process of vegetable fermentation.

RNA demethylase ALKBH5 regulates hypopharyngeal squamous cell carcinoma ferroptosis by posttranscriptionally activating NFE2L2/NRF2 in an m6 A-IGF2BP2-dependent manner.

BACKGROUND: Having emerged as the most abundant posttranscriptional internal mRNA modification in eukaryotes, N6-methyladenosine (m6 A) has attracted tremendous scientific interest in recent years. However, the functional importance of the m6 A methylation machinery in ferroptosis regulation in hypopharyngeal squamous cell carcinoma (HPSCC) remains unclear. METHODS: We herein performed bioinformatic analysis, cell biological analyses, transcriptome-wide m6 A sequencing (m6 A-seq, MeRIP-seq), RNA sequencing (RNA-seq), and RNA immunoprecipitation sequencing (RIP-seq), followed by m6 A dot blot, MeRIP-qPCR, RIP-qPCR, and dual-luciferase reporter assays. RESULTS: The results revealed that ALKBH5-mediated m6 A demethylation led to the posttranscriptional inhibition of NFE2L2/NRF2, which is crucial for the regulation of antioxidant molecules in cells, at two m6 A residues in the 3'-UTR. Knocking down ALKBH5 subsequently increased the expression of NFE2L2/NRF2 and increased the resistance of HPSCC cells to ferroptosis. In addition, m6 A-mediated NFE2L2/NRF2 stabilization was dependent on the m6 A reader IGF2BP2. We suggest that ALKBH5 dysregulates NFE2L2/NRF2 expression in HPSCC through an m6 A-IGF2BP2-dependent mechanism. CONCLUSION: Together, these results have revealed an association between the ALKBH5-NFE2L2/NRF2 axis and ferroptosis, providing insight into the functional importance of reversible mRNA m6 A methylation and its modulators in HPSCC.

Role of anti-angiogenic factors in the pathogenesis of breast cancer: A review of therapeutic potential.

Breast cancer is one of the most common cancers in women, which can metastasize to other organs and has a high mortality rate. Previous studies have shown that angiogenic factors can contribute to tumor growth, development, and metastasis by altering the tumor microenvironment (TME). These angiogenic factors include a wide range of molecules, and in contrast, anti-angiogenic factors also inhibit angiogenesis and inhibit tumor growth. Evidence suggests that an imbalance between angiogenic and anti-angiogenic factors leads to angiogenesis, facilitating the migration of tumor cells from the source tissue in the breast to other organs such as the lung, liver, bone, and brain. By supplying blood through these neomicrovascular vessels, the nutrients and oxygen needed to grow tumor cells are provided. Due to the significant anti-tumor role of anti-angiogenesis factors, cancer researchers have always considered these molecules, and it is believed that anti-angiogenesis factors can be employed in cancer treatment approaches. This review discusses the role of anti-angiogenesis agents in breast cancer pathogenesis and reviews therapeutic approaches based on anti-angiogenesis factors.

Hydrogels for localized chemotherapy of liver cancer: a possible strategy for improved and safe liver cancer treatment.

The systemic drug has historically been preferred for the treatment of the majority of pathological conditions, particularly liver cancer. Indeed, this mode of treatment is associated with adverse reactions, toxicity, off-target accumulation, and rapid hepatic and renal clearance. Numerous efforts have been made to design systemic therapeutic carriers to improve retention while decreasing side effects and clearance. Following systemic medication, local administration of therapeutic agents allows for higher 'effective' doses with fewer side effects, kidney accumulation, and clearance. Hydrogels are highly biocompatible and can be used for both imaging and therapy. Hydrogel-based drug delivery approach has fewer side effects than traditional chemotherapy and can deliver drugs to tumors for a longer time. The chemical and physical flexibility of hydrogels can be used to achieve disease-induced in situ accumulation as well as subsequent drug release and hydrogel-programmed degradation. Moreover, they can act as a biocompatible depot for localized chemotherapy when stimuli-responsive carriers are administrated. Herein, we summarize the design strategies of various hydrogels used for localized chemotherapy of liver cancer and their delivery routes, as well as recent research on smart hydrogels.

Clinical characteristics and patient outcomes of molecular subtypes of small cell lung cancer (SCLC).

BACKGROUND: Recent studies have shown that according to the expression levels of achaete-scute homolog 1 (ASCL1), neurogenic differentiation factor 1 (NEUROD1), and POU class 2 homeobox 3 (POU2F3), small cell lung cancer (SCLC) can be divided into four subtypes: SCLC-A (ASCL1-dominant), SCLC-N (NEUROD1-dominant), SCLC-P (POU2F3-dominant), and SCLC-I (triple negative or SCLC-inflamed). However, there are limited data on the clinical characteristics and prognosis of molecular subtypes of SCLC. METHODS: Immunohistochemistry (IHC) was used to detect the expression levels of ASCL1, NEUROD1, and POU2F3 in 53 patient samples of resectable SCLC. The subtype was defined by the differential expression of the transcription factors for ASCL1, NEUROD1, and POU2F3 or the low expression of all three factors with an inflamed gene signature (SCLC-A, SCLC-N, SCLC-P, and SCLC-I, respectively). The clinicopathological characteristics, immunological features (programmed death ligand 1 [PD-L1] expression and CD8+ tumor infiltrating lymphocyte [TIL] density), and patient outcomes of the four subtypes of SCLC were analyzed. RESULTS: Positive ASCL1, NEUROD1, and POU2F3 staining was detected in 43 (79.2%), 27 (51.0%), and 17 (32.1%) SCLC specimens by IHC. According to the results of IHC analysis, SCLC was divided into four subtypes: SCLC-A (39.6%), SCLC-N (28.3%), SCLC-P (17.0%), and SCLC-I (15.1%). The 5-year overall survival (OS) rates of these four subtypes were 61.9%, 69.3%, 41.7%, and 85.7%, respectively (P=0.251). There were significant differences in smoking status among different subtypes of SCLC (P= 0.031). However, we did not confirm the correlation between subtypes of SCLC and other clinicopathological factors or immune profiles. Cox multivariate analysis showed that N stage (P=0.025), CD8+ TILs (P=0.024), Ki-67 level (P=0.040), and SCLC-P (P=0.023) were independent prognostic factors for resectable SCLC. CONCLUSIONS: Our IHC-based study validated the proposed classification of SCLC using the expression patterns of key transcriptional regulatory factors. We found that SCLC-P was associated with smokers and was one of the poor prognostic factors of limited-stage SCLC. In addition, no correlation was found between PD-L1 expression or CD8+ TIL density and SCLC subtypes.