Localized fine-tuning and clinical evaluation of deep-learning based auto-segmentation (DLAS) model for clinical target volume (CTV) and organs-at-risk (OAR) in rectal cancer radiotherapy.

BACKGROUND AND PURPOSE: Various deep learning auto-segmentation (DLAS) models have been proposed, some of which have been commercialized. However, the issue of performance degradation is notable when pretrained models are deployed in the clinic. This study aims to enhance precision of a popular commercial DLAS product in rectal cancer radiotherapy by localized fine-tuning, addressing challenges in practicality and generalizability in real-world clinical settings. MATERIALS AND METHODS: A total of 120 Stage II/III mid-low rectal cancer patients were retrospectively enrolled and divided into three datasets: training (n = 60), external validation (ExVal, n = 30), and generalizability evaluation (GenEva, n = 30) datasets respectively. The patients in the training and ExVal dataset were acquired on the same CT simulator, while those in GenEva were on a different CT simulator. The commercial DLAS software was first localized fine-tuned (LFT) for clinical target volume (CTV) and organs-at-risk (OAR) using the training data, and then validated on ExVal and GenEva respectively. Performance evaluation involved comparing the LFT model with the vendor-provided pretrained model (VPM) against ground truth contours, using metrics like Dice similarity coefficient (DSC), 95th Hausdorff distance (95HD), sensitivity and specificity. RESULTS: LFT significantly improved CTV delineation accuracy (p < 0.05) with LFT outperforming VPM in target volume, DSC, 95HD and specificity. Both models exhibited adequate accuracy for bladder and femoral heads, and LFT demonstrated significant enhancement in segmenting the more complex small intestine. We did not identify performance degradation when LFT and VPM models were applied in the GenEva dataset. CONCLUSIONS: The necessity and potential benefits of LFT DLAS towards institution-specific model adaption is underscored. The commercial DLAS software exhibits superior accuracy once localized fine-tuned, and is highly robust to imaging equipment changes.

Integrative analysis of single-cell and bulk RNA sequencing unveils a machine learning-based pan-cancer major histocompatibility complex-related signature for predicting immunotherapy efficacy.

Major histocompatibility complex (MHC) could serve as a potential biomarker for tumor immunotherapy, however, it is not yet known whether MHC could distinguish potential beneficiaries. Single-cell RNA sequencing datasets derived from patients with immunotherapy were collected to elucidate the association between MHC and immunotherapy response. A novel MHCsig was developed and validated using large-scale pan-cancer data, including The Cancer Genome Atlas and immunotherapy cohorts. The therapeutic value of MHCsig was further explored using 17 CRISPR/Cas9 datasets. MHC-related genes were associated with drug resistance and MHCsig was significantly and positively associated with immunotherapy response and total mutational burden. Remarkably, MHCsig significantly enriched 6% top-ranked genes, which were potential therapeutic targets. Moreover, we generated Hub-MHCsig, which was associated with survival and disease-special survival of pan-cancer, especially low-grade glioma. This result was also confirmed in cell lines and in our own clinical cohort. Later low-grade glioma-related Hub-MHCsig was established and the regulatory network was constructed. We provided conclusive clinical evidence regarding the association between MHCsig and immunotherapy response. We developed MHCsig, which could effectively predict the benefits of immunotherapy for multiple tumors. Further exploration of MHCsig revealed some potential therapeutic targets and regulatory networks.

Surgery of enlarging lesions after stereotactic radiosurgery for brain metastases in patients with non-small cell lung cancer with oncogenic driver mutations frequently reveals radiation necrosis: case series and review.

In brain metastases, radiation necrosis (RN) is a complication that arises after single or multiple fractionated stereotactic radiosurgery (SRS/FSRS), which is challenging to distinguish from local recurrence (LR). Studies have shown increased RN incidence rates in non-small cell lung cancer (NSCLC) patients with oncogenic driver mutations (ODMs) or receiving tyrosine kinase inhibitors (TKIs). This study investigated enlarging brain lesions following SRS/FSRS, for which additional surgeries were performed to distinguish between RN and LR. We investigated seven NSCLC patients with ODMs undergoing SRS/FSRS for BM and undergoing surgery for suspicion of LR on MRI imaging. Descriptive statistics were performed. Among the seven patients, six were EGFR+, while one was ALK+. The median irradiation dose was 30 Gy (range, 20-35 Gy). The median time to develop RN after SRS/FSRS was 11.1 months (range: 6.3-31.2 months). Moreover, gradually enlarging lesions were found in all patients after 6 months post-SRS/FSR. Brain radiation necrosis was pathologically confirmed in all the patients. RN should be suspected in NSCLC patients when lesions keep enlarging after 6 months post-SRS/FSRS, especially for patients with ODMs and receiving TKIs. Further, this case series indicates that further dose reduction might be necessary to avoid RN for such patients.

Exposure to particulate matter may affect semen quality via trace metals: Evidence from a retrospective cohort study on fertile males.

Particulate matter (PM) exposure may be associated with male semen quality. Besides, PM exposure induces up and down levels of trace metals in tissues or organs. The levels of trace metals in semen are critical for adverse male semen quality. This study aims to evaluate the concentrations of seminal-level trace metals in fertile men and assess its associations with PM exposure and to explore the mediation role of trace metals in seminal plasma plays in the relationship between PM exposure and semen quality. Total 1225 fertile men who participated in a cohort study from 2014 to 2016 were finally recruited. Multivariate linear regression was applied to explore associations between each two of PM exposure, trace metals and semen parameters. 1-year PM2.5 and PM10 exposure levels were positively associated with arsenic (As), mercury (Hg), lanthanum (La), praseodymium (Pr), neodymium (Nd) but negatively associated with vanadium (V), magnesium (Mg), strontium (Sr), barium (Ba) in semen. It was also found that most of the elements were associated with total sperm number, followed by sperm concentration. Redundancy analysis (RDA) also determined several strong positive correlations or negative correlations between 1-year PM exposure and trace metals. Mediation analysis found that trace metals had a potentially compensatory or synergetic indirect effect on the total effect of the association between 1-year PM exposure and semen quality. The retrospective cohort study provides long-term PM exposure that may cause abnormal semen quality by affecting seminal plasma element levels.

Alterations in sperm DNA methylation may as a mediator of paternal air pollution exposure and offspring birth outcomes: Insight from a birth cohort study.

Paternal exposure to environmental risk factors influences the offspring health. This study aimed to evaluate the association between paternal air pollution exposure mediated by sperm DNA methylation and adverse birth outcomes in offspring. We recruited 1607 fertile men and their partners from 2014 to 2016 and collected semen samples to detect sperm DNA methylation. Multivariate linear regression and weighted quantile sum regression models were used to assess the associations between paternal air pollution exposure and offspring birth outcomes. A critical exposure window was identified. Reduced representation bisulfite sequencing was used to detect sperm DNA methylation. The results demonstrated that high paternal exposure to PM2.5 (ß = -211.31, 95% CI: (-386.37, -36.24)), PM10 (ß = -178.20, 95% CI: (-277.13, -79.27)), and NO2 (ß = -84.22, 95% CI: (-165.86, -2.57)) was negatively associated with offspring's birthweight, especially in boys. Additionally, an early exposure window of 15-69 days before fertilization was recognized to be the key exposure window, which increased the risk of low birth weight and small for gestational age. Furthermore, paternal co-exposure to six air pollutants contributed to lower birthweight (ß = -51.91, 95% CI: (-92.72, -11.10)) and shorter gestational age (ß = -1.72, 95% CI: (-3.26, -0.17)) and PM2.5 was the most weighted pollutant. Paternal air pollution exposure resulted in 10,328 differentially methylated regions and the IGF2R gene was the key gene involved in the epigenetic process. These differentially methylated genes were predominantly associated with protein binding, transcriptional regulation, and DNA templating. These findings indicate that spermatogenesis is a susceptible window during which paternal exposure to air pollution affects sperm DNA methylation and the birth outcomes of offspring.

Identification of potential LncRNAs as papillary thyroid carcinoma biomarkers based on integrated bioinformatics analysis using TCGA and RNA sequencing data.

The roles and mechanisms of long non-coding RNAs (lncRNAs) in papillary thyroid cancer (PTC) remain elusive. We obtained RNA sequencing (RNA-seq) data of surgical PTC specimens from patients with thyroid cancer (THCA; n = 20) and identified differentially expressed genes (DEGs) between cancer and cancer-adjacent tissue samples. We identified 2309 DEGs (1372 significantly upregulated and 937 significantly downregulated). We performed Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set enrichment, and protein-protein interaction network analyses and screened for hub lncRNAs. Using the same methods, we analyzed the RNA-seq data from THCA dataset in The Cancer Genome Atlas (TCGA) database to identify differentially expressed lncRNAs. We identified 15 key differentially expressed lncRNAs and pathways that were closely related to PTC. Subsequently, by intersecting the differentially expressed lncRNAs with hub lncRNAs, we identified LINC02407 as the key lncRNA. Assessment of the associated clinical characteristics and prognostic correlations revealed a close correlation between LINC02407 expression and N stage of patients. Furthermore, receiver operating characteristic curve analysis showed that LINC02407 could better distinguish between cancerous and cancer-adjacent tissues in THCA patients. In conclusion, our findings suggest that LINC02407 is a potential biomarker for PTC diagnosis and the prediction of lymph node metastasis.

Nrf2 in TIME: The Emerging Role of Nuclear Factor Erythroid 2-Related Factor 2 in the Tumor Immune Microenvironment.

Nuclear factor erythroid 2-related factor 2 (Nrf2) mediates the cellular antioxidant response, allowing adaptation and survival under conditions of oxidative, electrophilic and inflammatory stress, and has a role in metabolism, inflammation and immunity. Activation of Nrf2 provides broad and long-lasting cytoprotection, and is often hijacked by cancer cells, allowing their survival under unfavorable conditions. Moreover, Nrf2 activation in established human tumors is associated with resistance to chemo-, radio-, and immunotherapies. In addition to cancer cells, Nrf2 activation can also occur in tumor-associated macrophages (TAMs) and facilitate an anti-inflammatory, immunosuppressive tumor immune microenvironment (TIME). Several cancer cell-derived metabolites, such as itaconate, L-kynurenine, lactic acid and hyaluronic acid, play an important role in modulating the TIME and tumor-TAMs crosstalk, and have been shown to activate Nrf2. The effects of Nrf2 in TIME are context-depended, and involve multiple mechanisms, including suppression of pro-inflammatory cytokines, increased expression of programmed cell death ligand 1 (PD-L1), macrophage colony-stimulating factor (M-CSF) and kynureninase, accelerated catabolism of cytotoxic labile heme, and facilitating the metabolic adaptation of TAMs. This understanding presents both challenges and opportunities for strategic targeting of Nrf2 in cancer.

Detection of BRAF V600E in Fine-Needle Aspiration Samples of Thyroid Nodules by Droplet Digital PCR.

Background: BRAF exon 15 p.V600E (BRAF V600E) mutation has been established as an important molecular marker for papillary thyroid carcinoma diagnosis by ultrasound-guided fine-needle aspiration biopsy (FNAB). Sanger sequencing is the gold standard for detecting BRAF V600E mutations but fails to identify low-frequency mutations. However, droplet digital PCR (ddPCR) is a popular new method for detecting low-frequency mutations. Here, we compare the efficiency of droplet digital PCR (ddPCR) and Sanger sequencing for detection of the BRAF V600E mutation in thyroid fine-needle aspiration (FNA) samples. Methods: Thyroid fine-needle aspiration samples from 278 patients with 310 thyroid nodules were collected. Sanger sequencing and ddPCR were conducted to detect the BRAF V600E mutation. Results: The BRAF V600E mutation was found in 94 nodules (30.32%) by ddPCR and 40 nodules (12.90%) by Sanger sequencing in 310 FNA samples. A total of 119 nodules were confirmed PTC by postsurgical pathology. Among which the BRAF mutation was found in 80 (67.23%) nodules by ddPCR and 31 (26.05%) by Sanger sequencing. All nodules carrying the mutation detected by Sanger sequencing (SS+) were verified by ddPCR (ddPCR+). Also, all nodules with no mutation detected by ddPCR were interpreted as wild-type by Sanger sequencing (SS-). In addition. Almost all SS+/ddPCR + nodules (95.00%; 38/40) and SS-/ddPCR + nodules (100.00%; 54/54) displayed a BRAF mutation rate of >5% and <15%, respectively, indicating easy misdetection by Sanger sequencing when the mutation rate is between 5 and 15%. Conclusion: ddPCR has higher sensitivity than Sanger sequencing and we propose ddPCR as a supplement to Sanger sequencing in molecular testing of BRAF using FNAB samples.

Band-Pass Filtering Cross-Polarization Converter Using Transmitarrays.

Microwave devices with polarization conversion and band-pass filtering response have great application prospects on radomes. Here, the concepts of band-pass filters and cross-polarization converters are combined to realize a band-pass filtering cross-polarization converter with an extremely high polarization-conversion ratio. Most importantly, the device has an excellent out-of-band rejection level, above 30 and 40 dB for the lower and upper edges, respectively. In addition, the transmission zeros of the passband can be flexibly tuned independently. The band-pass filtering polarization converter was simulated, fabricated, and measured, and the measured results were found to be in good agreement with the simulation results.

Ultrasound-visualized, site-specific vascular embolization using magnetic protein microcapsules.

Imaging-guided vascular embolization is frequently performed on patients with advanced hepatocellular carcinoma (HCC) to alleviate symptoms and extend their survival time. Current operation procedures are not only painful for patients, but are also inaccurate in tumor targeting after the release of embolic agents from the catheter, leading to injury to healthy tissues simultaneously. In this study, we developed an ultrasound-visualized, site-specific vascular embolization strategy with magnetic protein microcapsules (MPMs). MPMs were fabricated using a rapid emulsification method, giving it a smooth surface and a core-shell structure. Their diameters could be controlled within 10 µm, allowing them to pass through capillaries. The core-shell structure and loading of magnetic Fe3O4 endowed MPMs with good contrast under ultrasound imaging and magnetically inducible targeting properties, as well as aggregation response even under flowing conditions. In vitro cytotoxicity and hemolysis evaluation demonstrated good biocompatibility of the MPMs. Furthermore, mock embolization showed that cell death could be induced by aggregation of the MPMs. Such a combination of real-time monitoring using ultrasound and control on targeted vascular embolization might be a breakthrough in the treatment of advanced HCC.

Intraoperative 99mTc-MIBI-Guided Parathyroidectomy Improves Curative Effect of Parathyroidectomy, Bone Metabolism, and Bone Mineral Density.

This study aimed to compare the postoperative effects of total parathyroidectomy plus forearm transplantation and radioguided parathyroidectomy on bone metabolism and bone mineral density (BMD). From June 2013 to October 2017, 67 patients with renal secondary hyperparathyroidism (SHPT) received surgical treatment. The control group included 30 cases of classical total parathyroidectomy plus forearm transplantation for SHPT. In the experimental group, 37 patients underwent 99mTc-MIBI-guided parathyroidectomy. Demographics, parathyroid hormone (PTH) level, blood calcium level, and pathological results were compared between the 2 groups. The curative effect of parathyroidectomy and its effect on BMD were also compared. The BMDs in the L1-L4 segments and femoral neck in both groups were significantly improved after operation (all P < .05). The T scores of the L1-L4 segments and femoral neck in both groups were significantly improved after operation (all P < .05). The improvement in the T score of the L4 in the experimental group was significantly higher than that in the control group (P < .05). No significant differences in the improvement in the L1-L3 segments and femoral neck were found between the 2 groups. Both traditional total parathyroidectomy plus forearm transplantation and 99mTc-MIBI-guided parathyroidectomy can improve PTH level, blood calcium level, phosphorus level, bone metabolism, and BMD to varying degrees in patients with SHPT. Compared with the traditional surgery, 99mTc-MIBI-guided parathyroidectomy can improve blood calcium and phosphorus metabolisms, reduce PTH level, and improve the T scores of L4 to a greater extent.

Long non­coding RNA MEG3 suppresses epithelial­to­mesenchymal transition by inhibiting the PSAT1­dependent GSK­3ß/Snail signaling pathway in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is the main subtype of esophageal cancer in China, and the prognosis of patients remains poor mainly due to the occurrence of lymph node and distant metastasis. The long non­coding RNA (lncRNA) maternally expressed gene 3 (MEG3) has been shown to have tumor­suppressive properties and to play an important role in epithelial­to­mesenchymal transition (EMT) in some solid tumors. However, whether MEG3 is involved in EMT in ESCC remains unclear. In the present study, the MEG3 expression level and its association with tumorigenesis were determined in 43 tumor tissues of patients with ESCC and in ESCC cells using reverse transcription­quantitative PCR analysis. Gene microarray analysis was performed to detect differentially expressed genes (DEGs). Based on the functional annotation results, the effects of ectopic expression of MEG3 on cell growth, migration, invasion and EMT were assessed. MEG3 expression level was found to be markedly lower in tumor tissues and cells. Statistical analysis revealed that MEG3 expression was significantly negatively associated with lymph node metastasis and TNM stage in ESCC. Fluorescence in situ hybridization assay demonstrated that MEG3 was expressed mainly in the nucleus. Ectopic expression of MEG3 inhibited cell proliferation, migration, invasion and cell cycle progression in EC109 cells. Gene microarray results demonstrated that 177 genes were differentially expressed ≥2.0 fold in MEG3­overexpressing cells, including 23 upregulated and 154 downregulated genes. Functional annotation revealed that the DEGs were mainly involved in amino acid biosynthetic process, mitogen­activated protein kinase signaling, and serine and glycine metabolism. Further experiments indicated that the ectopic expression of MEG3 significantly suppressed cell proliferation, migration, invasion and EMT by downregulating phosphoserine aminotransferase 1 (PSAT1). In pathological tissues, PSAT1 and MEG3 were significantly negatively correlated, and high expression of PSAT1 predicted poor survival. Taken together, these results suggest that MEG3 may be a useful prognostic biomarker and may suppress EMT by inhibiting the PSAT1­dependent glycogen synthase kinase­3ß/Snail signaling pathway in ESCC.

Effect of CXCR5-Positive Cell Infiltration on the Immune Contexture and Patient Prognosis in Head and Neck Squamous Cell Carcinoma.

PURPOSE: CXCR5-positive (CXCR5+) tumor cell infiltration has different prognostic values in different types of cancer. The objective was to evaluate the effect of CXCR5+ cell infiltration in head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: The study included two patient cohorts: The Cancer Genome Atlas cohort (TCGA, n = 472) and the Renji Hospital cohort (RJHC, n = 201). The TCGA and RJHC cohorts were analyzed for CXCR5-related mRNAs and CXCR5+ cell infiltration, respectively. We then evaluated the correlation between CXCR5 mRNA and CXCR5+ cell infiltration in terms of overall survival and the immune contexture. RESULTS: The 5-year overall survival rate was significantly correlated with high CXCR5 mRNA expression and CXCR5+ cell infiltration in the TCGA and RJHC cohorts, respectively (p < 0.01), even after adjusting for confounders. Moreover, high CXCR5 mRNA expression was associated with more CD4+ T cells, CD8+ T cells, plasma cells, and less dendritic cells. A high CXCR5 mRNA expression was also correlated with increased expression of cytotoxic IFNG, TNFSF11 (RANKL), GZMA, GZMB, GZMK, GZMM, and PRF1 and increased expression of the immunosuppressive gene PDCD1 (PD-1), CD274 (PD-L1), CTLA4, LAG3, HAVCR2 (TIM-3), BTLA, and TIGIT. CONCLUSION: HNSCC patients with a high intratumoral CXCR5 expression had a better prognosis than those with low intratumoral CXCR5 expression. Moreover, CXCR5+ cell infiltration could be used as an independent prognostic biomarker or as a potential therapeutic target. The presence of CXCR5+ cells affects the infiltration of immunocytes in head and neck cancer, differently from what was reported in other cancer types. Further randomized controlled trials or studies with more patients are needed to validate our results.

Activation of AMPK promotes thyroid cancer cell migration through its interaction with PKM2 and ß-catenin.

AMP-activated protein kinase (AMPK) is induced by the exhaustion of cellular energy and activates adaptive alterations in cellular metabolism, which is the basis for cell survival during different environmental stresses. We aimed to investigate the biological functions of AMPK and its molecular mechanism in regulating thyroid cancer (TC) progression. In current study, we found that activation of AMPK by multiple agonists suppresses TC cell proliferation. However, AMPK activation also led to TC cell migration at the same time. Depletion of AMPK abolished the effect of its agonist on cell multiplication and migration. Mechanistic investigations revealed that the impact of AMPK in terms of cell migration is dependent on its nuclear translocation, since site mutation of AMPK in its nuclear translocation domain (K244A) abolished TC cell migration but did not affect the inhibition of cell proliferation by AMPK agonist. Moreover, the nuclear AMPK recruits PKM2 and ß-catenin by their interaction, which promotes the transcription of cell migration related genes, including MMP7 and c-Myc. Furthermore, depletion of PKM2/ß-catenin abolished the migration effect of AMPK agonists, but did not affect their effects on suppression of cell proliferation. Our results provided a novel function of AMPK in cancer migration, and suggested that a combination of AMPK activation and PKM2 depletion or inhibition can be a new strategy to achieve better therapeutic effects for TC patients.

Dual-Band Transmissive Cross-Polarization Converter with Extremely High Polarization Conversion Ratio Using Transmitarray.

In this paper, a dual-band cross-polarization converter is proposed. The proposed device can convert linearly polarized incident waves to their cross-polarized transmitted waves. Inspired by the aperture coupled transmitarray, a transmissive multi-layered unit cell structure was designed, which can operate in two frequency bands. The designed structure can manipulate the polarization of the transmitted wave into the cross-polarization of the incident waves at 10.36 GHz and 11.62 GHz. The cross-polarized transmittance of the proposed cross-polarization converter is higher than 0.93. In addition, the transmitted wave has an extremely low co-polarized component, which results in a nearly 100% polarization conversion ratio. The two working frequencies can be tuned independently. The proposed cross-polarization converter was simulated, fabricated and measured. The simulation results confirm with the measurement results.

Inhibition of autophagy enhances adenosine­induced apoptosis in human hepatoblastoma HepG2 cells.

In cancer research, autophagy acts as a double­edged sword: it increases cell viability or induces cell apoptosis depending upon the cell context and functional status. Recent studies have shown that adenosine (Ado) has cytotoxic effects in many tumors. However, the role of autophagy in Ado­induced apoptosis is still poorly understood. In the present study, Ado­induced apoptotic death and autophagy in hepatoblastoma HepG2 cells was investigated and the relationship between autophagy and apoptosis was identified. In the present study, it was demonstrated that Ado inhibited HepG2 cell growth in a time­ and concentration­dependent manner and activated endoplasmic reticulum (ER) stress, as indicated by G0/G1 cell cycle arrest, the increased mRNA and protein levels of GRP78/BiP, PERK, ATF4, CHOP, cleaved caspase­3, cytochrome c and the loss of mitochon-drial membrane potential (ΔΨm). Ado also induced autophagic flux, revealed by the increased expression of the autophagy marker microtubule­associated protein 1 light chain 3­II (LC3­II), Beclin­1, autophagosomes, and the degradation of p62, as revealed by western blot analysis and macrophage­derived chemokine (MDC) staining. Blocking autophagy using LY294002 notably entrenched Ado­induced growth inhibition and cell apoptosis, as demonstrated with the increased expression of cytochrome c and p62, and the decreased expression of LC3­II. Conversely, the autophagy inducer rapamycin alleviated Ado­induced apoptosis and markedly increased the ΔΨm. Moreover, knockdown of AMPK with si­AMPK partially abolished Ado­induced ULK1 activation and mTOR inhibition, and thus reinforced CHOP expression and Ado­induced apoptosis. These results indicated that Ado­induced ER stress resulted in apoptosis and autophagy concurrently. The AMPK/mTOR/ULK1 signaling pathway played a protective role in the apoptotic procession. Inhibition of autophagy may effectively enhance the anticancer effect of Ado in human hepatoblastoma HepG2 cells.

E4BP4 promotes thyroid cancer proliferation by modulating iron homeostasis through repression of hepcidin.

Iron homeostasis is critical to mammals, and dysregulation in iron homeostasis usually leads to severe disorders including various cancers. Massive hepcidin secretion is an indicator of thyroid cancer, but the molecular mechanisms responsible for this dysregulation are unknown. Hepcidin secretion from thyroid cancer cells also leads to decreased expression of the iron exporter, ferroportin (FPN), and increased intracellular iron retention, which promote cancer proliferation. In this study, we examined the role of hepcidin in thyroid cancer (TC) and the molecular bases of its signaling. Synthesis of hepcidin is regulated by the BMP4/7 agonist SOSTDC1, which was downregulated in TC; SOSTDC1 downregulation was correlated with G9a-mediated hypermethylation in its promoter. The binding of G9a to the SOSTDC1 promoter requires E4BP4, which interacts with G9a to form a multi-molecular complex that contributes to SOSTDC1 silencing. Silencing of E4BP4 or G9a has similar effects to SOSTDC1 overexpression, which suppresses secretion of hepcidin and inhibits TC cell proliferation. Furthermore, our in vivo xenograft data indicated that depletion of E4BP4 also inhibits cancer growth, reduces hepcidin secretion, and reduces G9a nuclear transportation. Iron homeostasis and tumor growth in TC may be regulated by an E4BP4-dependent epigenetic mechanism. These findings suggest a new mechanism of cellular iron dysfunction through the E4BP4/G9a/SOSTDC1/hepcidin pathway, which is an essential link in TC.

Combined use of a nanocarbon suspension and 99mTc-MIBI for the intra-operative localization of the parathyroid glands.

OBJECTIVE: To investigate the combined use of a nanocarbon (NC) suspension and low-dose 99mTc-MIBI for parathyroid localization during surgery in patients with secondary hyperparathyroidism (sHPT). METHODS: Between March 2010 and September 2015, 40 patients with sHPT were enrolled in this study and were randomized to receive either low-dose 99mTc-MIBI+NC (group I) or low-dose 99mTc-MIBI (group II). Pre- and post-operative serum levels of intact PTH (iPTH), calcium and phosphorus between groups were compared and the intra-operative radioactive counts of the parathyroid glands were measured. RESULTS: The post-operative iPTH level was significantly lower in patients of group I (24.2±31ng/L) than in those of group II (106±155ng/L) (P=0.03) while there were no significant differences in intra-operative parathyroid gland radioactive counts between the groups. The duration of the surgical procedure was shorter for patients of group I than patients of group II. There were no serious intra-operative or post-operative complications. CONCLUSION: The combined use of an NC suspension and 99mTc-MIBI for patients with sHPT is strongly recommended for the localization of parathyroid glands during surgery and is likely to improve clinical outcomes for patients.

SOSTDC1 inhibits follicular thyroid cancer cell proliferation, migration, and EMT via suppressing PI3K/Akt and MAPK/Erk signaling pathways.

The sclerostin domain containing protein 1 (SOSTDC1) is a cell signaling regulator involved in cell physiology and pathology. SOSTDC1 is known to have a suppressive effect on certain kinds of cancer. However, the role of SOSTDC1 in follicular thyroid cancer (FTC) remains unknown. We aimed to investigate if the expression of SOSTDC1 plays any roles in carcinogenesis and metastasis of FTC. We found a significantly down-regulated SOSTDC1 expression in follicular thyroid cancer samples. In addition, our data showed that ectopic expression of SOSTDC1 dramatically inhibited thyroid cancer cell proliferation in vitro and in nude mice. SOSTDC1 also compromised the migratory, invasive property, and epithelial-mesenchymal transition (EMT) activity of FTC cell. Mechanically, SOSTDC1 exerted its tumor suppressor function by inhibiting the activity of major signaling pathways including the phosphatidylinositol-3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK)/Erk pathways. Altogether, our findings provide insight into the role of SOSTDC1 as a novel functional tumor suppressor in follicular thyroid cancer through modulating the activities of PI3K/Akt and MAPK/Erk signaling pathways.

Involvement of endoplasmic reticulum stress and p53 in lncRNA MEG3-induced human hepatoma HepG2 cell apoptosis.

Long non-coding RNAs (lncRNAs) play important roles in diverse biological processes. Although downregulation of lncRNA maternally expressed gene 3 (MEG3) has been identified in several types of cancers, little is known concerning its biological role and regulatory mechanism in hepatoma. Our previous studies demonstrated that MEG3 induces apoptosis in a p53-dependent manner. The aim of the present study was to determine whether endoplasmic reticulum (ER) stress is involved in MEG3­induced apoptosis. Recombinant lentiviral vectors containing MEG3 (Lv­MEG3) were constructed and transfected into HepG2 cells. A 3­(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, RT­PCR, flow cytometry, western blot analysis, immunofluorescence and immunohistochemistry were applied. Transfected HepG2 cells were also transplanted into nude mice, and the tumor growth curves were determined. The results showed that the recombinant lentivirus of MEG3 was transfected successfully into the HepG2 cells and the expression level of MEG3 was significantly increased. Ectopic expression of MEG3 inhibited HepG2 cell proliferation in vitro and in vivo, and also induced apoptosis. Ectopic expression of MEG3 increased ER stress­related proteins 78­kDa glucose­regulated protein (GRP78), inositol­requiring enzyme 1 (IRE1), RNA­dependent protein kinase­like ER kinase (PERK), activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), caspase­3, as well as p53 and NF­κB expression accompanied by NF­κB translocation from the cytoplasm to the nucleus. Furthermore, inhibition of NF­κB with Bay11­7082 decreased p53 expression in the MEG3­transfected cells. These results indicate that MEG3 inhibits cell proliferation and induces apoptosis, partially via the activation of the ER stress and p53 pathway, in which NF­κB signaling is required for p53 activation in ER stress.