Exploring thyroxine binding globulin structural changes and its release from human hepatoblastoma cells upon interaction with silica particles: A prelude to unrevealing the mechanism of thyroid hormone dysregulation.

Endocrine dysregulation in the presence of environmental chemical risk factors is a global adverse health concern. The aim of this investigation was to explore the structural changes and binding affinity of thyroxine (T4) binding protein (TBG) upon interaction with SiO2 particles as the second largest mineral in the Earth's crust and one of the most important constituents of rock, soil, and dust. Therefore, the interaction of TBG with SiO2 particles was assessed by fluorescence quenching, molecular docking, ANS and synchronous fluorescence, and far-UV CD analyses. Also, the release of TBG from human hepatoblastoma cell line, Hep G2, was assessed by ELISA assay. The results displayed that the value of stoichiometry of binding site (n) of TBG for T4 was approximately equal to one, which was reduced to 0.36 in the presence of SiO2 particles. Also, the binding affinity (Kb) values revealed that the binding affinity between T4 and TBG was strong (97.90 × 105 L/mol), while the presence of SiO2 particles resulted in the calculation of a Kb around 0.00159 × 105 L/mol, which was significantly lower than that of the absence of SiO2 particles. This data was also verified by molecular docking analyses which indicated that SiO2 particles interacted with the T4 binding pocket of TBG. Moreover, further studies exhibited that although the equimolar concentration of T4 to TBG resulted in the superior stability of TBG-T4 complex relative to free TBG, the presence of SiO2 particles with the same concentration led to denaturation of the secondary structure of TBG. Furthermore, it was seen that the amount of released TBG in the cell culture medium of Hep G2 was about 2.21 ng/mL protein, whereas this amount in SiO2 particles-treated cell group was significantly reduced to 1.71 ng/mL protein (*P < 0.05). In conclusion, this study implies that SiO2 particles show the potential to result in inhibition of TBG release, TBG denaturation, and interfere with TBG binding affinity which may lead to dysregulation of the thyroid hormone transport and associated signaling pathways.

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.

FTO regulates the chemo-radiotherapy resistance of cervical squamous cell carcinoma (CSCC) by targeting ß-catenin through mRNA demethylation.

The role of N6 -methyladenosine (m6 A) demethylase fat mass and obesity-associated protein (FTO) in the regulation of chemo-radiotherapy resistance remains largely unknown. Here, we show that the mRNA level of FTO is elevated in cervical squamous cell carcinoma (CSCC) tissues when compared with respective adjacent normal tissues. FTO enhances the chemo-radiotherapy resistance both in vitro and in vivo through regulating expression of ß-catenin by reducing m6 A levels in its mRNA transcripts and in turn increases excision repair cross-complementation group 1 (ERCC1) activity. Clinically, the prognostic value of FTO for overall survival is found to be dependent on ß-catenin expression in human CSCC samples. Taken together, these findings uncover a critical function for FTO and its substrate m6 A in the regulation of chemo-radiotherapy resistance, which may bear potential clinical implications for CSCC treatment.

Prognostic Value of Neutrophil-Related Factors in Locally Advanced Cervical Squamous Cell Carcinoma Patients Treated with Cisplatin-Based Concurrent Chemoradiotherapy.

The aim of this study was to explore the relationship between neutrophil-related factors, including neutrophil-lymphocyte ratio (NLR) and the responses of neutrophil to granulocyte colony-stimulating factors (RNG), and the prognosis of patients with locally advanced cervical squamous cell carcinoma (LACSCC) undergoing cisplatin-based concurrent chemoradiotherapy (CCCRT). A total of sixty LACSCC patients were enrolled in this study. We analyzed the association of NLR or RNG with clinicopathologic characteristics of these patients. The prognostic factors were evaluated by univariate and multivariate survival analysis. The optimal cut-off value of the NLR was determined to be 2.0 for the overall survival (OS). A higher level of the NLR was associated with younger age (P = 0.017) and higher baseline platelet count (P = 0.040). NLR was identified to be the only independent prognostic factor for OS by multivariate analysis (P = 0.037). The median RNG was 3.01, with a range of 1.19-16.84. RNG level was significantly associated with lymph node metastasis of these patients (P = 0.023). And higher RNG was identified as being a closely independent poor prognostic factor for OS (P = 0.055). This study showed that NLR and RNG may be used as potential biomarkers for survival prediction in patients with LACSCC receiving CCCRT.

ERCC1 mRNA levels can predict the response to cisplatin-based concurrent chemoradiotherapy of locally advanced cervical squamous cell carcinoma.

BACKGROUND: The purpose of this study was to investigate whether the excision repair cross-complementation group 1 (ERCC1) mRNA expression could predict treatment response of patients with locally advanced cervical squamous cell carcinoma (LACSCC) who underwent cisplatin-based concurrent chemoradiotherapy (CCCRT). METHODS: A total of sixty LACSCC patients, treated with radical CCCRT from a single institution were evaluated. ERCC1 mRNA expression was determined by quantitative real-time RT-PCR in pre-treatment tumor tissues. The association of ERCC1 status with clinicopathological characteristics (age, histological grade, tumor size, parametrial invasion, lymph node metastasis and FIGO stage) and treatment response were analyzed. RESULTS: No significant association between ERCC1 mRNA expression and clinicopathological characteristics were observed. Patients with low ERCC1 mRNA level had a significantly higher rate of complete response (86.21%) than patients with high level of ERCC1 expression (19.36%; p < 0.001). In the logistic regression analysis, low ERCC1 mRNA level retained an independent role in predicting complete response to CCCRT (P < 0.001). An ERCC1 expression level of 0.0901 was determined as an optimal cutoff value to identify complete response patients to CCCRT treatment. The sensitivity for detection of a complete response was 81.48% with a specificity of 96.97% (area under the curve, 0.893; 95% confidence interval, 0.804-0.983). CONCLUSIONS: This is the first analysis of the association between ERCC1 mRNA levels and treatment response in patients with LACSCC. Low ERCC1 mRNA level appears to be a highly specific predictor of response to CCCRT in LACSCC.