Improving radiomics reproducibility using deep learning-based image conversion of CT reconstruction algorithms in hepatocellular carcinoma patients.

OBJECTIVES: CT reconstruction algorithms affect radiomics reproducibility. In this study, we evaluate the effect of deep learning-based image conversion on CT reconstruction algorithms. METHODS: This study included 78 hepatocellular carcinoma (HCC) patients who underwent four-phase liver CTs comprising non-contrast, late arterial (LAP), portal venous (PVP), and delayed phase (DP), reconstructed using both filtered back projection (FBP) and advanced modeled iterative reconstruction (ADMIRE). PVP images were used to train a convolutional neural network (CNN) model to convert images from FBP to ADMIRE and vice versa. LAP, PVP, and DP images were used for validation and testing. Radiomic features were extracted for each patient with a semi-automatic segmentation tool. We used concordance correlation coefficients (CCCs) to evaluate the radiomics reproducibility for original FBP (oFBP) vs. original ADMIRE (oADMIRE), oFBP vs. converted FBP (cFBP), and oADMIRE vs. converted ADMIRE (cADMIRE). RESULTS: In the test group including 30 patients, the CCC and proportion of reproducible features (CCC ≥ 0.85) for oFBP vs. oADMIRE were 0.65 and 32.9% (524/1595) for LAP, 0.65 and 35.9% (573/1595) for PVP, and 0.69 and 43.8% (699/1595) for DP. For oFBP vs. cFBP, the values increased to 0.92 and 83.9% (1339/1595) for LAP, 0.89 and 71.0% (1133/1595) for PVP, and 0.90 and 79.7% (1271/1595) for DP. Similarly, for oADMIRE vs. cADMIRE, the values increased to 0.87 and 68.1% (1086/1595) for LAP, 0.91 and 82.1% (1309/1595) for PVP, and 0.89 and 76.2% (1216/1595) for DP. CONCLUSIONS: CNN-based image conversion between CT reconstruction algorithms improved the radiomics reproducibility of HCCs. CLINICAL RELEVANCE STATEMENT: This study demonstrates that using a CNN-based image conversion technique significantly improves the reproducibility of radiomic features in HCCs, highlighting its potential for enhancing radiomics research in HCC patients. KEY POINTS: Radiomics reproducibility of HCC was improved via CNN-based image conversion between two different CT reconstruction algorithms. This is the first clinical study to demonstrate improvements across a range of radiomic features in HCC patients. This study promotes the reproducibility and generalizability of different CT reconstruction algorithms in radiomics research.

Ibulocydine Inhibits Migration and Invasion of TNBC Cells via MMP-9 Regulation.

Triple-negative breast cancer (TNBC) accounts for approximately 15-20% of all breast cancer types, indicating a poor survival prognosis with a more aggressive biology of metastasis to the lung and a short response duration to available therapies. Ibulocydine (IB) is a novel (cyclin-dependent kinase) CDK7/9 inhibitor prodrug displaying potent anti-cancer effects against various cancer cell types. We performed in vitro and in vivo experiments to determine whether IB inhibits metastasis and eventually overcomes the poor drug response in TNBC. The result showed that IB inhibited the growth of TNBC cells by inducing caspase-mediated apoptosis and blocking metastasis by reducing MMP-9 expression in vitro. Concurrently, in vivo experiments using the metastasis model showed that IB inhibited metastasis of MDA-MB-231-Luc cells to the lung. Collectively, these results demonstrate that IB inhibited the growth of TNBC cells and blocked metastasis by regulating MMP-9 expression, suggesting a novel therapeutic agent for metastatic TNBC.

Dietary intakes of branched-chain amino acids and plasma lipid profiles among filipino women in Korea: the Filipino Women's Diet and Health Study (FiLWHEL).

BACKGROUND: The potential role of dietary branched-chain amino acids (BCAA) in metabolic health, including cardiovascular disease and diabetes, is evolving, and it is yet to be understood if dietary BCAA intakes are associated with plasma lipid profiles or dyslipidaemia. This study tested the association of dietary BCAA intakes with plasma lipid profiles and dyslipidaemia among Filipino women in Korea. METHODS: Energy-adjusted dietary BCAA intakes (isoleucine, leucine, valine, and total BCAA) and fasting blood profiles of triglycerides (TG), total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C) were determined in a sample of 423 women enrolled in the Filipino Women's Diet and Health Study (FiLWHEL). The generalized linear model was applied to estimate least-square (LS) means and 95% confidence intervals (CIs) and compare plasma TG, TC, HDL-C, and LDL-C across tertile distribution of energy-adjusted dietary BCAA intakes at P < 0.05. RESULTS: Mean of energy-adjusted dietary total BCAA intake was 8.3 ± 3.9 g/d. Average plasma lipid profiles were 88.5 ± 47.4 mg/dl for TG, 179.7 ± 34.5 mg/dl for TC, 58.0 ± 13.7 mg/dl for HDL-C, and 104.0 ± 30.5 mg/dl for LDL-C. LS means, and 95% CIs across tertiles of energy-adjusted total BCAA intakes were 89.9 mg/dl, 88.8 mg/dl and 85.8 mg/dl (P-trend = 0.45) for TG, 179.1 mg/dl, 183.6 mg/dl and 176.5 mg/dl (P-trend = 0.48) for TC, 57.5 mg/dl, 59.6 mg/dl and 57.1 mg/dl (P-trend = 0.75) for HDL-C and 103.6 mg/dl, 106.2 mg/dl and 102.3 mg/dl (P-trend = 0.68) for LDL-C. Furthermore, the multivariable-adjusted prevalence ratios and 95% confidence intervals for dyslipidaemia across increasing tertile distribution of energy-adjusted total BCAA intake were; 1.00, 0.67 (0.40, 1.13) and 0.45 (0.16, 1.27; P-trend = 0.03) for the first, second and third tertile, respectively. CONCLUSIONS: Higher dietary intakes of BCAA presented a statistically significant inverse trend with the prevalence of dyslipidaemia among Filipino women in this study and testing these associations in longitudinal studies may be necessary to confirm these findings.

Comparison of cardiovascular disease risk factors among FiLWHEL (2014-2016), NNS (2013) and KNHANES (2013-2015) women.

OBJECTIVES: This study assessed the CVD risk factors among Filipino women (FW) in Korea and compared them with FW in the Philippines and women in Korea (KW). METHODS: A cohort of 504 women from the Filipino Women's Health and Diet Study (FiLWHEL) aged 20-57 years old were age-matched (1:1 ratio) with women from the 2013 National Nutrition Survey in the Philippines and the 2013-2015 Korean National Health and Nutrition Examination Survey. Anthropometric data, blood pressure (BP), lipid and glucose levels were compared across the four populations by calculating the odds ratio (OR)s and 95% confidence interval (CI)s using conditional logistic regression models. RESULTS: Compared to KW, FW in Korea and FW in the Philippines were more than 2 and 3 times higher odds of having obesity for BMI ≥ 30 kg/m2 and waist circumference ≥ 88 cm, respectively. However, FW in Korea had the highest odds (OR 5.51, 95% CI 3.18-9.56) of having hypertension compared to KW. FW in the Philippines had the highest odds of having dyslipidemia (compared to KW, total cholesterol ≥ 200 mg/dL: OR 8.83, 95% CI 5.30-14.71; LDL-C ≥ 130 mg/dL: OR 3.25, 95% CI 2.13-4.98; and triglyceride ≥ 150 mg/dL: OR 2.59, 95% CI 1.59-4.22), but FW in Korea and KW had similar prevalence of dyslipidemia. CONCLUSIONS: FW in Korea had higher prevalence of obesity and hypertension, with similar prevalence of dyslipidemia compared to KW in this sample. FW in the Philippines had higher prevalence of dyslipidemia compared to FW in Korea. Further prospective studies are warranted to examine the CVD risk factors among continental and native-born Filipino women.

Dose reduction potential of vendor-agnostic deep learning model in comparison with deep learning-based image reconstruction algorithm on CT: a phantom study.

OBJECTIVES: To compare the dose reduction potential (DRP) of a vendor-agnostic deep learning model (DLM, ClariCT.AI) with that of a vendor-specific deep learning-based image reconstruction algorithm (DLR, TrueFidelity™). METHODS: Computed tomography (CT) images of a multi-sized image quality phantom (Mercury v4.0) were acquired under six radiation dose levels (0.48/0.97/1.93/3.87/7.74/15.47 mGy) and were reconstructed using filtered back projection (FBP) and three strength levels of the DLR (low/medium/high). The FBP images were denoised using the DLM. For all DLM and DLR images, the detectability index (d') (a task-based detection performance metric) was obtained, under various combinations of three target sizes (10/5/1 mm), five inlets (CT value difference with the background; -895/50/90/335/1000 HU), five phantom diameters (36/31/26/21/16 cm), and six radiation dose levels. Dose reduction potential (DRP) measures the dose reduction made by using DLM or DLR, while yielding d' equivalent to that of FBP at full dose. RESULTS: The DRPs of the DLM, DLR-low, DLR-medium, and DLR-high were 86% (81-88%), 60% (46-67%), 76% (60-81%), and 87% (78-92%), respectively. For 10-mm targets, the DRP of the DLM (87%) was higher than that of all DLR algorithms (58-86%). However, for smaller targets (5 mm/1 mm), the DRPs of the DLR-high (89/88%) were greater than those of the DLM (87/84%). CONCLUSION: The dose reduction potential of the vendor-agnostic DLM was shown to be comparable to that of the vendor-specific DLR at high strength and superior to those of the DLRs at medium and low strengths. KEY POINTS: • DRP of the vendor-agnostic model was comparable to that of high-strength vendor-specific model and superior to those of medium- and low-strength models. • Under various radiation dose levels, the deep learning model shows higher detectability indexes compared to FBP.

Identification of bilge oil with lubricant: Recent oil spill case studies.

Oil spills have many adverse effects on the marine environment. Bilge oil spills occur frequently in the sea as a result of maritime accidents or illegal discharge. It is difficult to unambiguously identify the specific sources of such spills because bilge oil contains a mixture of fuel oil and lubricant. In this study, bilge oils with different fuel oil/lubricant ratios were prepared and analyzed using a modified version of the CEN/TR methodology (European Committee for Standardization, 2012). As the lubricant content of bilge oil increased, the intensity of the C20-C24 group, which is the commonly-used normalization compound group for fuel oil in the percentage weathering (PW) plot, also changed. Therefore, the mean area of the C15-C18 group, which was affected by the lubricant content, was used instead. Although heavy fuel oil is usually normalized to a hopane, bilge oil with a high lubricant content cannot be analyzed based on a mass spectrometry (MS)-PW plot; thus, heavy fuel oil-based bilge oil was normalized to a phytane in this study. Although hopanes and styrenes are unsuitable comparison compounds for heavy fuel oil-based bilge oil analysis, for light fuel oil-based bilge oil, hopanes and steranes could be applied as diagnostic ratio comparisons when the lubricant peak was clearly detected in the chromatograms of the spilled and suspected oil samples. By applying the CEN/TR methodology according to this approach, the similarities between spilled and suspected oil samples were more easily revealed. In addition, the field applicability of the proposed method was tested for four actual oil spills.

Dietary branched-chain amino acids and odds of obesity among immigrant Filipino women: the Filipino women's diet and health study (FiLWHEL).

BACKGROUND: The dietary environment promoting adiposity keeps evolving and of interest is the significance of dietary branched-chain amino acids (BCAA). This study assessed the association between dietary BCAA intakes and odds of obesity among immigrant Filipino women in Korea. METHOD: We included 423 immigrant Filipino women enrolled in the Filipino Women's diet and health study in the Republic of Korea. Dietary BCAA intakes were estimated from 24 hour recalls and adjusted for energy intake using the residual method. General obesity was derived from direct anthropometric measurements (height, weight and waist circumference - WC) and defined as body mass index (BMI) ≥25 kg/m2 and abdominal obesity as WC ≥80 cm. Odds ratios (OR) and 95% confidence intervals (CI) by tertile distribution of energy-adjusted BCAA intakes were estimated using multivariable logistic regression with a two-sided P < 0.05. RESULTS: Median (interquartile range) for BCAA intakes in g/day were; 7.9 (5.8, 10.3) g/day for total BCAA; 2.0 (1.5, 2.6) g/day for isoleucine, 3.5(2.5, 4.6) g/day for leucine and 2.4 (1.8, 3.1) g/day for valine. Mean BMI and WC were 23.6 ± 3.8 kg/m2 and 79.8 ± 9.3 cm, respectively. Also, 30.2% (128) had BMI ≥25 kg/m2 and 42.0% (178) had WC ≥80 cm. ORs (95%CIs) of general obesity across tertile distribution of energy-adjusted total BCAA intakes were 1.00, 0.81 (0.47, 1.37) and 0.62 (0.36, 1.07; P for trend = 0.08). A similar trend was observed across tertile distribution of energy-adjusted isoleucine, leucine and valine intakes. However, there was a statistically significant inverse association between total BCAA intake and odds of general obesity in a subset of non-smokers; 1.00, 0.68 (0.39, 1.20) and 0.55 (0.31, 0.98; P for trend = 0.04). CONCLUSION: We found a suggestive inverse association between higher dietary BCAA intake and odds of obesity in this sample of immigrant Filipino women, particularly among non-smokers. Prospective cohort studies among the immigrant population will be necessary to verity these findings.

Echinochrome A Inhibits Melanogenesis in B16F10 Cells by Downregulating CREB Signaling.

Excessive increase in melanin pigment in the skin can be caused by a variety of environmental factors, including UV radiation, and can result in spots, freckles, and skin cancer. Therefore, it is important to develop functional whitening cosmetic reagents that regulate melanogenesis. In this study, we investigated the effects of echinochrome A (Ech A) on melanogenesis in the B16F10 murine melanoma cell line. We triggered B16F10 cells using α-MSH under Ech A treatment to observe melanin synthesis and analyze expression changes in melanogenesis-related enzymes (tyrosinase, tyrosinase-related protein 1 (TYRP1), and tyrosinase-related protein 2 (TYRP2)) at the mRNA and protein levels. Furthermore, we measured expression changes in the microphthalmia-associated transcription factor (MITF), CREB, and pCREB proteins. Melanin synthesis in the cells stimulated by α-MSH was significantly reduced by Ech A. The expression of the tyrosinase, TYRP1, and TYRP2 mRNA and proteins was significantly decreased by Ech A, as was that of the MITF, CREB, and pCREB proteins. These results show that Ech A suppresses melanin synthesis by regulating melanogenesis-related enzymes through the CREB signaling pathway and suggest the potential of Ech A as a functional agent to prevent pigmentation and promote skin whitening.

Multitask Siamese Network for Remote Photoplethysmography and Respiration Estimation.

Heart and respiration rates represent important vital signs for the assessment of a person's health condition. To estimate these vital signs accurately, we propose a multitask Siamese network model (MTS) that combines the advantages of the Siamese network and the multitask learning architecture. The MTS model was trained by the images of the cheek including nose and mouth and forehead areas while sharing the same parameters between the Siamese networks, in order to extract the features about the heart and respiratory information. The proposed model was constructed with a small number of parameters and was able to yield a high vital-sign-prediction accuracy, comparable to that obtained from the single-task learning model; furthermore, the proposed model outperformed the conventional multitask learning model. As a result, we can simultaneously predict the heart and respiratory signals with the MTS model, while the number of parameters was reduced by 16 times with the mean average errors of heart and respiration rates being 2.84 and 4.21. Owing to its light weight, it would be advantageous to implement the vital-sign-monitoring model in an edge device such as a mobile phone or small-sized portable devices.

Correction: Chang et al. Decursinol Angelate Arrest Melanoma Cell Proliferation by Initiating Cell Death and Tumor Shrinkage via Induction of Apoptosis. Int. J. Mol. Sci. 2021, 22, 4096.

The author wishes to make the following correction to this paper [...].

Depletion of HNRNPA1 induces peroxisomal autophagy by regulating PEX1 expression.

Peroxisomes play an essential role in cellular homeostasis by regulating lipid metabolism and the conversion of reactive oxygen species (ROS). Several peroxisomal proteins, known as peroxins (PEXs), control peroxisome biogenesis and degradation. Various mutations in the PEX genes are genetic causes for the development of inheritable peroxisomal-biogenesis disorders, such as Zellweger syndrome. Among the peroxins, PEX1 defects are the most common mutations in Zellweger syndrome. PEX1 is an AAA-ATPase that regulates the recycling of PEX5, which is essential for importing peroxisome matrix proteins. However, the post-transcriptional regulation of PEX1 is largely unknown. Here, we showed that heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) controls PEX1 expression. In addition, we found that depletion of HNRNPA1 induces autophagic degradation of peroxisome, which is blocked in ATG5-knockout cells. In addition, depletion of HNRNPA1 increased peroxisomal ROS levels. Inhibition of the generation of peroxisomal ROS by treatment with NAC significantly suppressed pexophagy in HNRNPA1-deficient cells. Taken together, our results suggest that depletion of HNRNPA1 increases peroxisomal ROS and pexophagy by downregulating PEX1 expression.

Inhibition of STAT3 enhances sensitivity to tamoxifen in tamoxifen-resistant breast cancer cells.

BACKGROUND: The mechanisms of endocrine resistance are complex, and deregulation of several oncogenic signalling pathways has been proposed. We aimed to investigate the role of the EGFR and Src-mediated STAT3 signalling pathway in tamoxifen-resistant breast cancer cells. METHODS: The ER-positive luminal breast cancer cell lines, MCF-7 and T47D, were used. We have established an MCF-7-derived tamoxifen-resistant cell line (TamR) by long-term culture of MCF-7 cells with 4-hydroxytamoxifen. Cell viability was determined using an MTT assay, and protein expression levels were determined using western blot. Cell cycle and annexin V staining were analysed using flow cytometry. RESULTS: TamR cells showed decreased expression of estrogen receptor and increased expression of EGFR. TamR cells showed an acceleration of the G1 to S phase transition. The protein expression levels of phosphorylated Src, EGFR (Y845), and STAT3 was increased in TamR cells, while phosphorylated Akt was decreased. The expression of p-STAT3 was enhanced according to exposure time of tamoxifen in T47D cells, suggesting that activation of STAT3 can cause tamoxifen resistance in ER-positive breast cancer cells. Both dasatinib (Src inhibitor) and stattic (STAT3 inhibitor) inhibited cell proliferation and induced apoptosis in TamR cells. However, stattic showed a much stronger effect than dasatinib. Knockdown of STAT3 expression by siRNA had no effect on sensitivity to tamoxifen in MCF-7 cells, while that enhanced sensitivity to tamoxifen in TamR cells. There was not a significant synergistic effect of dasatinib and stattic on cell survival. TamR cells have low nuclear p21(Cip1) expression compared to MCF-7 cells and inhibition of STAT3 increased the expression of nuclear p21(Cip1) in TamR cells. CONCLUSIONS: The EGFR and Src-mediated STAT3 signalling pathway is activated in TamR cells, and inhibition of STAT3 may be a potential target in tamoxifen-resistant breast cancer. An increase in nuclear p21(Cip1) may be a key step in STAT3 inhibitor-induced cell death in TamR cells.

Environmental and Genetic Risk Factors of Congenital Anomalies: an Umbrella Review of Systematic Reviews and Meta-Analyses.

BACKGROUND: The prevalence of congenital anomalies in newborns in South Korea was 272.9 per 100,000 in 2005, and 314.7 per 100,000 in 2006. In other studies, the prevalence of congenital anomalies in South Korea was equivalent to 286.9 per 10,000 livebirths in 2006, while it was estimated 446.3 per 10,000 births during the period from 2008 to 2014. Several systematic reviews and meta-analyses analyzing the factors contributing to congenital anomalies have been reported, but comprehensive umbrella reviews are lacking. METHODS: We searched PubMed, Google Scholar, Cochrane, and EMBASE databases up to July 1, 2019, for systematic reviews and meta-analyses that investigated the effects of environmental and genetic factors on any type of congenital anomalies. We categorized 8 subgroups of congenital anomalies classified according to the 10th revision of the International Statistical Classification of Diseases (ICD-10). Two researchers independently searched the literature, retrieved the data, and evaluated the quality of each study. RESULTS: We reviewed 66 systematic reviews and meta-analyses that investigated the association between non-genetic or genetic risk factors and congenital anomalies. Overall, 269 associations and 128 associations were considered for environmental and genetic risk factors, respectively. Congenital anomalies based on congenital heart diseases, cleft lip and palate, and others were associated with environmental risk factors based on maternal exposure to environmental exposures (air pollution, toxic chemicals), parental smoking, maternal history (infectious diseases during pregnancy, pregestational and gestational diabetes mellitus, and gestational diabetes mellitus), maternal obesity, maternal drug intake, pregnancy through artificial reproductive technologies, and socioeconomic factors. The association of maternal alcohol or coffee consumption with congenital anomalies was not significant, and maternal folic acid supplementation had a preventive effect on congenital heart defects. Genes or genetic loci associated with congenital anomalies included MTHFR, MTRR and MTR, GATA4, NKX2-5, SRD5A2, CFTR, and 1p22 and 20q12 anomalies. CONCLUSION: This study provides a wide perspective on the distribution of environmental and genetic risk factors of congenital anomalies, thus suggesting future studies and providing health policy implications.

Decursinol Angelate Arrest Melanoma Cell Proliferation by Initiating Cell Death and Tumor Shrinkage via Induction of Apoptosis.

Melanoma is known to aggressively metastasize and is one of the prominent causes of skin cancer mortality. This study was designed to assess the molecular mechanism of decursinol angelate (DA) against murine melanoma cell line (B16F10 cells). Treatment of DA resulted in growth inhibition and cell cycle arrest at G0/G1 (p < 0.001) phase, evaluated through immunoblotting. Moreover, autophagy-related proteins such as ATG-5 (p < 0.0001), ATG-7 (p < 0.0001), beclin-1 (p < 0.0001) and transition of LC3-I to LC3-II (p < 0.0001) were markedly decreased, indicating autophagosome inhibition. Additionally, DA treatment triggered apoptotic events which were corroborated by the occurrence of distorted nuclei, elevated reactive oxygen species (ROS) levels and reduction in the mitochondrial membrane potential. Subsequently, there was an increase in the expression of pro-apoptotic protein Bax in a dose-dependent manner, with the corresponding downregulation of Bcl-2 expression and cytochrome C expression following 24 h DA treatment in A375.SM and B16F10 cells. We substantiated our results for apoptotic occurrence through flow cytometry in B16F10 cells. Furthermore, we treated B16F10 cells with N-acetyl-L-cysteine (NAC). NAC treatment upregulated ATG-5 (p < 0.0001), beclin-1 (p < 0.0001) and LC3-I to LC3-II (p < 0.0001) conversion, which was inhibited in the DA treatment group. We also noticed a systematic upregulation of important markers for progression of G1 cell phase such as CDK-2 (p < 0.029), CDK-4 (p < 0.036), cyclin D1 (p < 0.0003) and cyclin E (p < 0.020) upon NAC treatment. In addition, we also observed a significant fold reduction (p < 0.05) in ROS fluorescent intensity and the expression of Bax (p < 0.0001), cytochrome C (p < 0.0001), cleaved caspase-9 (p > 0.010) and cleaved caspase-3 (p < 0.0001). NAC treatment was able to ameliorate DA-induced apoptosis and cell cycle arrest to support our finding. Our in vivo xenograft model also revealed similar findings, such as downregulation of CDK-2 (p < 0.0001) and CDK-4 (p < 0.0142) and upregulation of Bax (p < 0.0001), cytochrome C (p < 0.0001), cleaved caspase 3 (p < 0.0001) and cleaved caspase 9 (p < 0.0001). In summary, our study revealed that DA is an effective treatment against B16F10 melanoma cells and xenograft mice model.

Poziotinib suppresses ovarian cancer stem cell growth via inhibition of HER4-mediated STAT5 pathway.

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, with an overall 5-year survival rate of only 30%. EOC is associated with drug resistance, frequent recurrence, and poor prognosis. A major contributor toward drug resistance might be cancer stem cells (CSCs), which may remain after chemotherapy. Here, we aimed to find therapeutic agents that target ovarian CSCs. We performed a high-throughput screening using the Clinical Compound Library with a sphere culture of A2780 EOCs. Poziotinib, a pan-human epidermal growth factor receptor (HER) inhibitor, decreased sphere formation, viability, and proliferation, and induced G1 cell cycle arrest and apoptosis in ovarian CSCs. In addition, poziotinib suppressed stemness and disrupted downstream signaling of Wnt/ß-catenin, Notch, and Hedgehog pathways, which contribute to many characteristics of CSCs. Interestingly, HER4 was overexpressed in ovarian CSCs and Poziotinib reduced the phosphorylation of STAT5, AKT, and ERK, which are regulated by HER4. Our results suggest that HER4 may be a promising therapeutic target for ovarian CSCs, and that poziotinib may be an effective therapeutic option for the prevention of ovarian cancer recurrence.

Combined Poziotinib with Manidipine Treatment Suppresses Ovarian Cancer Stem-Cell Proliferation and Stemness.

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy in women worldwide, with an overall 5 year survival rate below 30%. The low survival rate is associated with the persistence of cancer stem cells (CSCs) after chemotherapy. Therefore, CSC-targeting strategies are required for successful EOC treatment. Pan-human epidermal growth factor receptor 4 (HER4) and L-type calcium channels are highly expressed in ovarian CSCs, and treatment with the pan-HER inhibitor poziotinib or calcium channel blockers (CCBs) selectively inhibits the growth of ovarian CSCs via distinct molecular mechanisms. In this study, we tested the hypothesis that combination treatment with poziotinib and CCBs can synergistically inhibit the growth of ovarian CSCs. Combined treatment with poziotinib and manidipine (an L-type CCB) synergistically suppressed ovarian CSC sphere formation and viability compared with either drug alone. Moreover, combination treatment synergistically reduced the expression of stemness markers, including CD133, KLF4, and NANOG, and stemness-related signaling molecules, such as phospho-STAT5, phospho-AKT, phospho-ERK, and Wnt/ß-catenin. Moreover, poziotinib with manidipine dramatically induced apoptosis in ovarian CSCs. Our results suggest that the combinatorial use of poziotinib with a CCB can effectively inhibit ovarian CSC survival and function.

Calcium Channels as Novel Therapeutic Targets for Ovarian Cancer Stem Cells.

Drug resistance in epithelial ovarian cancer (EOC) is reportedly attributed to the existence of cancer stem cells (CSC), because in most cancers, CSCs still remain after chemotherapy. To overcome this limitation, novel therapeutic strategies are required to prevent cancer recurrence and chemotherapy-resistant cancers by targeting cancer stem cells (CSCs). We screened an FDA-approved compound library and found four voltage-gated calcium channel blockers (manidipine, lacidipine, benidipine, and lomerizine) that target ovarian CSCs. Four calcium channel blockers (CCBs) decreased sphere formation, viability, and proliferation, and induced apoptosis in ovarian CSCs. CCBs destroyed stemness and inhibited the AKT and ERK signaling pathway in ovarian CSCs. Among calcium channel subunit genes, three L- and T-type calcium channel genes were overexpressed in ovarian CSCs, and downregulation of calcium channel genes reduced the stem-cell-like properties of ovarian CSCs. Expressions of these three genes are negatively correlated with the survival rate of patient groups. In combination therapy with cisplatin, synergistic effect was shown in inhibiting the viability and proliferation of ovarian CSCs. Moreover, combinatorial usage of manidipine and paclitaxel showed enhanced effect in ovarian CSCs xenograft mouse models. Our results suggested that four CCBs may be potential therapeutic drugs for preventing ovarian cancer recurrence.

QKI, a miR-200 target gene, suppresses epithelial-to-mesenchymal transition and tumor growth.

The microRNA-200 (miR-200) family plays a major role in specifying epithelial phenotype by preventing expression of the transcription repressors ZEB1 and ZEB2, which are well-known regulators of the epithelial-to-mesenchymal transition (EMT) in epithelial tumors including oral squamous cell carcinoma (OSCC). Here, we elucidated whether miR-200 family members control RNA-binding protein quaking (QKI), a newly identified tumor suppressor that is regulated during EMT. We predicted that miR-200a and miR-200b could recognize QKI 3'-UTR by analyzing TargetScan and The Cancer Genome Atlas head and neck squamous cell carcinoma (HNSCC) dataset. Forced expression of miR-200b/a/429 inhibited expression of ZEB1/2 and decreased cell migration in OSCC cell lines CAL27 and HSC3. QKI expression was also suppressed by miR-200 overexpression, and the 3'-UTR of QKI mRNA was directly targeted by miR-200 in luciferase reporter assays. Interestingly, shRNA-mediated knockdown of QKI led to pronounced EMT and protumor effects in both in vitro and in vivo studies of OSCC. Furthermore, high expression of QKI protein is associated with favorable prognosis in surgically resected HNSCC and lung adenocarcinoma. In conclusion, QKI increases during EMT and is targeted by miR-200; while, it suppresses EMT and tumorigenesis. We suggest that QKI and miR-200 form a negative feedback loop to maintain homeostatic responses to EMT-inducing signals.

Heterogeneous nuclear ribonucleoprotein A1 promotes the expression of autophagy-related protein 6 in human colorectal cancer.

Autophagy, a lysosomal self-degradative process of cellular components, is essential for cellular homeostasis to response cellular stress and is tightly controlled by autophagy-related genes (ATGs). Autophagy-related gene 6 (ATG6, also known as Beclin-1 in human) is an essential factor regulating autophagy and apoptosis. RNA binding proteins (RBPs) regulate gene expression at the post-transcriptional level and their differential expression is linked to the pathogenesis of several human diseases. Here, we demonstrate the role of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) as a novel factor regulating ATG6 expression. hnRNPA1 associates with the 3' untranslated region (3'UTR) of ATG6 mRNA and promotes its expression without significant changes at the mRNA level. Knockdown of hnRNPA1 decreases ATG6 expression, which is enhanced by the overexpression of hnRNPA1. Also, we show augmented expression of both hnRNPA1 and ATG6 in the colorectal cancer (CRC) tissues obtained from patients and demonstrate a positive correlation of their expression in CRC tissues. Our results suggest the potential role of hnRNPA1-mediated ATG6 regulation in the pathogenesis of CRC.

Loss of RNA binding protein, human antigen R enhances mitochondrial elongation by regulating Drp1 expression in SH-SY5Y cells.

Mitochondria are essential for providing the energy necessary for neuronal function. Dysregulation of mitochondrial dynamics has been linked with the pathogenesis of many neurodegenerative diseases. Dynamin related protein 1 (Drp1) participates in fission activity in the mitochondria, and post-translational modifications to Drp1 modulate complex mitochondrial dynamics. However, the regulation of Drp1 at the post-transcriptional level remains poorly understood. In this study, we found that the RNA-binding protein Hu antigen R (HuR) post-transcriptionally regulates Drp1 expression. HuR interacts with Drp1 mRNA at its 3' untranslated region. Depletion of HuR reduces Drp1 expression, which leads to mitochondrial elongation in SH-SY5Y neuroblastoma cells. In contrast, ectopic expression of HuR enhances Drp1 expression, which promotes mitochondrial fragmentation in response to treatment with the mitochondrial complex 1 inhibitor MPP+. In addition, depletion of HuR suppressed the generation of mitochondrial ROS and cytotoxicity in MPP+ treated cells. Taken together, these findings suggest that HuR controls mitochondrial morphology via regulation of Drp1.