Relationship between METS-IR and thyroid cancer incidence in Korea: a nationwide population-based study.

Background: Several previous studies found a positive relationship between metabolic syndrome (MetS) and thyroid cancer (TC) risk. However, there is no research that has studied the relationship between the metabolic score for insulin resistance (METS-IR), a novel surrogate marker for IR, and TC incidence. Thus, we designed this retrospective cohort study to evaluate the relationship between the incidence of TC and METS-IR. Method: We analyzed a cohort of 314,321 Korean adults aged over 40 years who participated in the National Health Screening Program from 2009 to 2010. The individuals were divided into four groups based on METS-IR quartiles. Follow-up was until the diagnosis of TC or death, or until December 31, 2019, if neither. The relationship between METS-IR and TC incidence was analyzed using the Cox proportional-hazards model with multi-variable adjustments. Results: A total of 4,137 participants (1.3%) were diagnosed with TC during a mean follow-up of 9.5 ± 1.5 years. The population with Q1 METS-IR scores showed higher disease-free probabilities than those with Q4 METS-IR scores (p <0.001). The hazard ratio (95% confidential interval) for TC incidence in Q2, Q3, and Q4 METS-IR value were 1.14 (1.05 to 1.25), 1.21 (1.11 to 1.33), and 1.30 (1.18 to 1.42) compared with Q1 of METS-IR, respectively. The incidence of TC tended to increase with increasing METS-IR values in the total population, especially the male population in the restricted cubic spline. In subgroup analysis, the TC risk was more pronounced in the subgroups under 65 and with a BMI < 25 kg/m2. Conclusion: METS-IR was positively correlated with TC incidence in Korea.

Alcohol consumption and the risk of liver disease: a nationwide, population-based study.

Introduction: Although most patients with alcohol-related liver disease (ALD) have a history of prolonged and heavy drinking, there is no clear threshold defining the level of alcohol consumption that leads to ALD. We aimed to evaluate the correlation between average alcohol consumption and the risk of liver disease and to determine the threshold for clinically significant alcohol consumption. Materials and methods: Using the Korean National Health Insurance database, we identified participants who underwent a health-screening program in 2010 and 2011 and retrospectively analyzed their data until 2019. To diagnose and categorize the extracted participants, we used the International Classification of Diseases version 10 and Fatty Liver Index. The primary outcome was to determine the incidence of newly diagnosed liver-related diseases during the observation period and compare the incidence of liver-related diseases among non-drinkers and drinkers based on the amount of alcohol consumption. Results: A total of 53,006 patients were enrolled and followed-up for a median of 8.4 years, during which 1,509 cases of liver-related diseases occurred. The participants were divided into five groups: no alcohol consumption (n = 31,359), 1st quartile (n = 5,242), 2nd quartile (n = 5,704), 3rd quartile (n = 5,337), and 4th quartile (n = 5,364). The corresponding number of glasses of alcohol consumed per week for each quantile (Q1, Q2, Q3, and Q4) was labeled 2.5 ± 1.1 standard units (1 standard unit = 8 g alcohol), 5.4 ± 1.9 standard units, 11.5 ± 3.3 standard units, and 27.9 ± 18.2 standard units, respectively. Compared with non-drinkers, the risk of liver-related disease was found to be higher in Q1 drinkers (adjusted hazard ratio [aHR], 1.09; 95% CI, 0.90-1.33), Q2 drinkers (aHR, 1. 10; 95% CI, 0.91-1.32), Q3 drinkers (aHR, 1.33; 95% CI, 1.11-1.59), and Q4 drinkers (aHR, 1.47; 95% CI, 1.24-1.75). Conclusion: We report that our study has shown that drinking more than 11.5 ± 3.3 standard units/week (92 ± 26.4 g/week) significantly increases the risk of developing liver-related diseases. Therefore, as a preventive measure to reduce the risk of developing liver disease, alcohol consumption should be limited beyond traditionally recommended levels.

The Utility of Narrow-Band Imaging International Colorectal Endoscopic Classification in Predicting the Histologies of Diminutive Colorectal Polyps Using I-Scan Optical Enhancement: A Prospective Study.

(1) Background: This study aimed to evaluate the accuracy of predicting the histology of diminutive colonic polyps (DCPs) (≤5 mm) using i-scan optical enhancement (OE) based on the narrow-band imaging international colorectal endoscopic (NICE) classification. The study compared the diagnostic accuracy between experts who were already familiar with the NICE classification and trainees who were not, both before and after receiving brief training on the NICE classification. (2) Method: This prospective, single-center clinical trial was conducted at the Dong-A University Hospital from March 2020 to August 2020 and involved two groups of participants. The first group comprised two experienced endoscopists who were proficient in using i-scan OE and had received formal training in optical diagnosis and dye-less chromoendoscopy (DLC) techniques. The second group consisted of three endoscopists in the process of training in internal medicine at the Dong-A University Hospital. Each endoscopist examined the polyps and evaluated them using the NICE classification through i-scan OE. The results were not among the participants. Trained endoscopists were divided into pre- and post-training groups. (3) Results: During the study, a total of 259 DCPs were assessed using i-scan OE by the two expert endoscopists. They made real-time histological predictions according to the NICE classification criteria. For the trainee group, before training, the area under the receiver operating characteristic curves (AUROCs) for predicting histopathological results using i-scan OE were 0.791, 0.775, and 0.818. However, after receiving training, the AUROCs improved to 0.935, 0.949, and 0.963, which were not significantly different from the results achieved by the expert endoscopists. (4) Conclusions: This study highlights the potential of i-scan OE, along with the NICE classification, in predicting the histopathological results of DCPs during colonoscopy. In addition, this study suggests that even an endoscopist without experience in DLC can effectively use i-scan OE to improve diagnostic performance with only brief training.

Optimization of Nutrient-Rich Ice Plant (Mesembryanthemum crystallinum L.) Paste Fresh Noodle Pasta Using Response Surface Methodology.

The ice plant is a species that is grown mainly in the dry regions of the American West and contains various minerals and ingredients beneficial for human health, such as inositol and beta-carotene. With the growing trend towards healthy foods, pasta consumption has also increased. Pasta is a convenient and low-glycemic-index food that is composed mainly of carbohydrates, proteins, lipids, dietary fiber, and trace amounts of minerals. The optimal mixing ratio was evaluated to produce pasta of the highest quality in terms of blood sugar elevation and antioxidant efficacy. The components and minerals of the ice plant, including D-pinitol and inositol, were analyzed, and 20 essential amino acids were identified. In this study, we also investigated the quality and characteristics of ice plant paste and eggs, as well as the quality, antioxidant activity, and formulation of raw materials mixed with ice plant at different ratios. Optimal conditions were found to be 46.73 g of ice plant paste in 100 g of durum wheat flour, 20.23 g of egg, and 2 g of salt, providing a way to develop fresh pasta that enhances the health benefits of ice plant paste without excessive moisture and other ingredients.

A Case of Transverse Myelitis Following Treatment with Atezolizumab for Advanced Hepatocellular Carcinoma.

The results of the IMbrave150 study have led to widespread use of the combination therapy of atezolizumab and bevacizumab as a first-line treatment for unresectable or metastatic hepatocellular carcinoma (HCC). Compared to traditional cytotoxic chemotherapy agents, immune checkpoint inhibitors show a spectrum of side effects ranging from mild side effects such as skin rash to potentially severe systemic effects such as myocarditis. We present a case of transverse myelitis diagnosed during the treatment of HCC with atezolizumab and bevacizumab combination therapy.

The impact of face shields on the quality of gastrointestinal endoscopy during the COVID-19 pandemic.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has become a global pandemic, with healthcare workers at a high risk of exposure. During this pandemic, endoscopists must wear personal protective equipment (PPE), including face shields, to prevent COVID-19 transmission; however, few studies have reported the impact of face shields on the quality of gastrointestinal (GI) endoscopy. We aimed to determine whether the use of PPE, including face shields, affected the quality of GI endoscopy during the COVID-19 pandemic. METHODS: The medical records of patients who had undergone screening or surveillance colonoscopy and gastric endoscopic submucosal dissection (ESD) at Dong-A University Hospital between June 2020 and March 2021 were retrospectively reviewed. Endoscopists wore isolation gowns, disposable gloves, and KF94 masks from June 2020 to October 2020. From November 2020, endoscopists also wore face shields. We compared GI endoscopy quality indicators between the first five months (no face shields) and the second five months (with face shields). In the non-face shield and face shield groups, we calculated the overall adenoma detection rates (ADRs), polyp detection rate (PDR), sessile serrated lesion detection rate (SSLDR), advanced neoplasia detection rate (ANDR), complete resection rate (CRR), number of polyps and/or adenomas per colonoscopy, and gastric ESD procedure time. RESULTS: In total, 1359 study patients had undergone screening or surveillance colonoscopy (face shield group, n = 679; non-face shield group, n = 680). No statistically significant between-group differences were observed (PDR, 49.04 vs. 52.50%, p = 0.202; ADR, 38.59 vs. 38.97%, p = 0.884; SSPDR, 1.91 vs. 1.32%, p = 0.388; ANDR, 3.98 vs. 3.97%, p = 0.991, respectively). No difference was found in colonoscopy quality indicators between patients examined by experienced and trainee endoscopists with and without face shields. Of 144 study patients who had undergone gastric ESD for gastric neoplasms, there were 72 patients in each group. No statistically significant differences were found in the CRR (94.44 vs 93.05%, p = 1.000) and procedure times (19.22 ± 9.33 vs. 19.03 ± 11.49, p = 0.911). CONCLUSIONS: Wearing face shields during the COVID-19 pandemic did not affect the quality indicators for GI endoscopy.

Combination Therapy of the Active KRAS-Targeting Antibody inRas37 and a PI3K Inhibitor in Pancreatic Cancer.

KRAS activating mutations, which are present in more than 90% of pancreatic cancers, drive tumor dependency on the RAS/mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT signaling pathways. Therefore, combined targeting of RAS/MAPK and PI3K/AKT signaling pathways may be required for optimal therapeutic effect in pancreatic cancer. However, the therapeutic efficacy of combined MAPK and PI3K/AKT signaling target inhibitors is unsatisfactory in pancreatic cancer treatment, because it is often accompanied by MAPK pathway reactivation by PI3K/AKT inhibitor. Therefore, we developed an inRas37 antibody, which directly targets the intra-cellularly activated GTP-bound form of oncogenic RAS mutation and investigated its synergistic effect in the presence of the PI3K inhibitor BEZ-235 in pancreatic cancer. In this study, inRas37 remarkably increased the drug response of BEZ-235 to pancreatic cancer cells by inhibiting MAPK reactivation. Moreover, the co-treatment synergistically inhibited cell proliferation, migration, and invasion and exhibited synergistic anticancer activity by inhibiting the MAPK and PI3K pathways. The combined administration of inRas37and BEZ-235 significantly inhibited tumor growth in mouse models. Our results demonstrated that inRas37 synergistically increased the antitumor activity of BEZ-235 by inhibiting MAPK reactivation, suggesting that inRas37 and BEZ-235 co-treatment could be a potential treatment approach for pancreatic cancer patients with KRAS mutations.

Endoscopic Removal Through a Gastrostomy of Swallowed Acupuncture Needles.

Acupuncture is a representative treatment field in oriental medicine that is used widely in various medical conditions. Although acupuncture is considered a safe procedure, it can cause complications. This paper reports the case of a 44-year-old quadriplegic woman who received a percutaneous gastrostomy (PEG) tube and was referred for the endoscopic removal of swallowed acupuncture needles. The needles were removed successfully by endoscopy through the PEG tube using the rendezvous technique without significant complications.

Real-world Effectiveness and Safety of Direct-acting Antiviral Agents in Patients with Chronic Hepatitis C Genotype 2 Infection: Korean Multicenter Study.

BACKGROUND: The advancement of treatment with direct-acting antiviral (DAA) agents has improved the cure rate of hepatitis C virus (HCV) infection close to 100%. The aim of our study was to assess the real-world effectiveness and safety of DAA regimens for the treatment of patients with chronic HCV genotype 2. METHODS: We retrospectively analyzed the clinical data of patients treated with sofosbuvir plus ribavirin (SOF + RBV) or glecaprevir/pibrentasvir (G/P) for chronic HCV genotype 2 infection at seven university hospitals in the Korean southeast region. RESULTS: SOF + RBV therapy produced an 89% and 98.3% sustained virologic response 12 week (SVR12) after treatment completion in the full analysis set and per-protocol set, respectively, and the corresponding values for G/P therapy were 89.5% and 99.2%, respectively. The difference between the treatments was probably because 6.2% (59/953) of patients in the SOF + RBV group did not complete the treatment and 9.8% (14/143) in the G/P group did not test HCV RNA after treatment completion. Adverse events (A/Es) were reported in 59.7% (569/953) and 25.9% (37/143) of the SOF + RBV and G/P groups, respectively. In the SOF + RBV group, 12 (1.26%) patients discontinued treatment owing to A/Es, whereas no patients discontinued treatment because of A/Es in the G/P group. CONCLUSION: In both treatment groups, SVR was high when treatment was completed. However, there was a high dropout rate in the SOF + RBV group, and the dropout analysis showed that these were patients with liver cirrhosis (LC; 43/285, 15.1%), especially those with decompensated LC (12/32, 37.5%). Therefore, an early initiation of antiviral therapy is recommended for a successful outcome before liver function declines. Furthermore, patients with decompensated LC who are considered candidates for SOF + RBV treatment should be carefully monitored to ensure that their treatment is completed, especially those with low hemoglobin and high alanine transaminase.

Intracellular KRAS-specific antibody enhances the anti-tumor efficacy of gemcitabine in pancreatic cancer by inducing endosomal escape.

KRAS mutation is associated with the progression and growth of pancreatic cancer and contributes to chemo-resistance, which poses a significant clinical challenge in pancreatic cancer. Here, we developed a RT22-ep59 antibody (Ab) that directly targets the intracellularly activated GTP-bound form of oncogenic KRAS mutants after it is internalized into cytosol by endocytosis through tumor-associated receptor of extracellular epithelial cell adhesion molecule (EpCAM) and investigated its synergistic anticancer effects in the presence of gemcitabine in pancreatic cancer. We first observed that RT22-ep59 specifically recognized tumor-associated EpCAM and reached the cytosol by endosomal escape. In addition, the anticancer effect of RT22-ep59 was observed in the high-EpCAM-expressing pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells, but it had little effect on the low-EpCAM-expressing pancreatic cancer cells. Additionally, co-treatment with RT22-ep59 and gemcitabine synergistically inhibited cell viability, migration, and invasion in 3D-cultures and exhibited synergistic anticancer activity by inhibiting the RAF/ERK or PI3K/AKT pathways in cells with high-EpCAM expression. In an orthotopic mouse model, combined administration of RT22-ep59 and gemcitabine significantly inhibited tumor growth. Furthermore, the co-treatment suppressed cancer metastasis by blocking EMT signaling in vitro and in vivo. Our results demonstrated that RT22-ep59 synergistically increased the antitumor activity of gemcitabine by inhibiting RAS signaling by specifically targeting KRAS. This indicates that co-treatment with RT22-ep59 and gemcitabine might be considered a potential therapeutic strategy for pancreatic cancer patients harboring KRAS mutation.

Hemoperitoneum with Splenic Artery Rupture Following Diagnostic Colonoscopy.

Colonoscopy is a safe and extremely popular diagnostic and therapeutic procedure. The most common complications are bleeding and perforation. Hemoperitoneum is a rare complication after a colonoscopy and is usually associated with splenic injury or solid organ pathology. This is potentially serious and can be life threatening. With the increasing number of colonoscopies performed, there has also been an increasing trend in reports of rare complications, such as pneumothorax, pneumomediastinum, appendicitis, small bowel perforation, septicemia, mesenteric tear, retroperitoneal abscess, and hemoperitoneum. This paper reports a unique case of hemoperitoneum after a recent colonoscopy without a splenic rupture or intra-abdominal abnormality, or external trauma. Most hemoperitoneum occurs within 48 hours after the inciting colonoscopy. In the present case, however, hemoperitoneum appeared 10 days after the colonoscopy. This case emphasizes that physicians should consider hemoperitoneum in a differential diagnosis of abdominal pain in patients after colonoscopy.

Hypoxia-induced apoptosis of astrocytes is mediated by reduction of Dicer and activation of caspase-1.

Hypoxia is a condition in which the whole body or a region of the body is deprived of oxygen supply. The brain is very sensitive to the lack of oxygen and cerebral hypoxia can rapidly cause severe brain damage. Astrocytes are essential for the survival and function of neurons. Therefore, protecting astrocytes against cell death is one of the main therapeutic strategies for treating hypoxia. Hence, the mechanism of hypoxia-induced astrocytic cell death should be fully elucidated. In this study, astrocytes were exposed to hypoxic conditions using a hypoxia work station or the hypoxia mimetic agent cobalt chloride (CoCl2 ). Both the hypoxic gas mixture (1% O2 ) and chemical hypoxia-induced apoptotic cell death in T98G glioblastoma cells and mouse primary astrocytes. Reactive oxygen species were generated in response to the hypoxia-mediated activation of caspase-1. Active caspase-1 induced the classical caspase-dependent apoptosis of astrocytes. In addition, the microRNA processing enzyme Dicer was cleaved by caspase-3 during hypoxia. Knockdown of Dicer using antisense oligonucleotides induced apoptosis of T98G cells. Taken together, these results suggest that astrocytic cell death during hypoxia is mediated by the reactive oxygen species/caspase-1/classical caspase-dependent apoptotic pathway. In addition, the decrease in Dicer levels by active caspase-3 amplifies this apoptotic pathway via a positive feedback loop. These findings may provide a new target for therapeutic interventions in cerebral hypoxia.

KRAS targeting antibody synergizes anti-cancer activity of gemcitabine against pancreatic cancer.

Pancreatic cancer exhibits an oncogenic KRAS mutation rate of ∼90%. Despite research and drug development efforts focused on KRAS, no targeted therapy has been clinically approved for the treatment of pancreatic cancer with KRAS mutation. Also, the efficacy of gemcitabine is poor due to rapidly acquired resistance. We developed RT11-i antibody, which directly targets the intracellularly activated GTP-bound form of oncogenic RAS mutants. Here, we investigated the combined effects of RT11-i and gemcitabine in vitro and in vivo, and the mechanism involved. RT11-i significantly sensitized pancreatic cancer cells to gemcitabine. Also, the co-treatment synergistically inhibited angiogenesis, migration, and invasion, and showed synergistic anticancer activity by inhibiting the RAF/MEK/ERK or PI3K/AKT pathways. Furthermore, co-treatment inhibited endothelial barrier disruption in tumor vessels, which is a critical step in vascular leakiness of metastasis, and improved vessel structural stability. Importantly, co-treatment significantly suppressed tumor growth in an orthotopic tumor model. Taken together, our findings show that RT11-i synergistically increased the antitumor activity of gemcitabine by inhibiting RAS downstream signaling, which suggests RT11-i and gemcitabine be viewed a potential combination treatment option for pancreatic cancer patients with KRAS mutation.

Melatonin Synergizes with Sorafenib to Suppress Pancreatic Cancer via Melatonin Receptor and PDGFR-ß/STAT3 Pathway.

BACKGROUND/AIMS: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignant tumors with poor prognosis. Conventional chemotherapies including gemcitabine have failed owing to weak response and side effects. Hence novel treatment regimens are urgently needed to improve the therapeutic efficacy. In this study, we aimed to assess the anticancer activity of melatonin and sorafenib as a novel therapy against PDAC. METHODS: We used various apoptosis assay and PDAC xenograft model to assess anticancer effect in vitro and in vivo. We applied phospho-receptor tyrosine kinase (RTK) array and phospho-tyrosine kinase array to explore the mechanism of the combined therapy. Western blotting, proximity ligation assay, and immunoprecipitation assay were also performed for validation. RESULTS: Melatonin synergized with sorafenib to suppress the growth of PDAC both in vitro and in vivo. The effect was due to increased apoptosis rate of PDAC cells that was accompanied by mitochondria dysfunction. The enhanced anticancer efficacy by the co-treatment could be explained by blockade of PDGFR-ß/STAT3 signaling pathway and melatonin receptor (MT)-mediated STAT3. CONCLUSIONS: Melatonin reinforces the anticancer activity of sorafenib by downregulation of PDGFR-ß/STAT3 signaling pathway and melatonin receptor (MT)-mediated STAT3. The combination of the two agents might be a potential therapeutic strategy for treating PDAC.

A novel tropomyosin-related kinase A inhibitor, KK5101 to treat pancreatic cancer.

Tropomyosin-related kinase A (TrkA) plays important roles in tumor cell growth and survival signaling and contributes to chemo-resistance in pancreatic cancer. Therefore, we developed KK5101, a novel TrkA target inhibitor and assessed its anti-cancer effects and investigated underlying mechanism of action in pancreatic cancer. KK5101 was characterized to inhibit TrkA selectively and potently by protein binding assay. It effectively inhibited the growth and proliferation of pancreatic cancer cells. Also, KK5101 increased apoptosis with loss of mitochondrial membrane potential, as evidenced by increases of cytochrome c releases. It increased numbers of TUNEL-positive apoptotic cells, and cell death including early and late apoptosis by Annexin V assay. In addition, activation of the TrkA signaling cascades including p-AKT, p-MEK, and p-STAT3 were inhibited by KK5101 treatment in vitro, as well as ex vivo tumor spheroid models, resulting in potent induction of apoptosis. Importantly, KK5101 also significantly attenuated tumor growth of in vivo pancreatic cancer models. These findings indicate that KK5101 may exert antitumor effects by directly affecting cancer cell growth or survival via inhibition of TrkA signaling pathway. We therefore suggest that KK5101 is a novel therapeutic candidate for treating pancreatic cancer.

Tumor vessel normalization by the PI3K inhibitor HS-173 enhances drug delivery.

Tumor vessels are leaky and immature, which causes poor oxygen and nutrient supply to tumor vessels and results in cancer cell metastasis to distant organs. This instability of tumor blood vessels also makes it difficult for anticancer drugs to penetrate and reach tumors. Numerous tumor vessel normalization approaches have been investigated for improving drug delivery into tumors. In this study, we investigated whether phosphoinositide 3-kinase (PI3K) inhibitors are able to improve vascular structure and function over the prolonged period necessary to achieve effective vessel normalization. The PI3K inhibitors, HS-173 and BEZ235 potently suppressed tumor growth and hypoxia, and increased tumor apoptosis in animal models. PI3K inhibitors also induced a regular, flat monolayer of endothelial cells (ECs) in vessels, improving stability of vessel structure, and normalized tumor vessels by increasing vascular maturity, pericyte coverage, basement membrane thickness, and tight-junctions. These effects resulted in a decrease in tumor vessel tortuosity and vessel thinning, and improved vessel function and blood flow. The tumor vessel stabilization effect of the PI3K inhibitor HS-173 also decreased the number of metastatic lung nodules in vivo metastasis model. Furthermore, HS-173 improved the delivery of doxorubicin into the tumor region, enhancing its anticancer effects. Mechanistic studies suggested that PI3K inhibitor HS-173-induced vessel normalization reflected changes in endothelial Notch signaling. Taken together, our findings indicate that vessel normalization by PI3K inhibitors restrained tumor growth and metastasis while improving chemotherapy by enhancing drug delivery into the tumor, suggesting that HS-173 may have a therapeutic value as an enhancer or an anticancer drug.

CCL11 promotes angiogenic activity by activating the PI3K/Akt pathway in HUVECs.

CCR3, the receptor for CCL11, is expressed on the surface of immune cells and even on non-immune cells. CCL11-CCR3 interactions can promote cell migration and proliferation. In this study, we investigated the effect of CCL11 on angiogenesis in HUVECs and also examined the molecular mechanisms of this process. We found that CCL11 induced mRNA transcription and protein expression of CCR3 in HUVECs. Moreover, the scratch wound healing assay and MTS proliferation assay both demonstrated that CCL11 promotes endothelial cell migration and induces weak proliferation. CCL11 directly induced microvessel sprouting from the rat aortic ring; these effects occurred earlier and to a greater extent than with VEGF stimulation. Furthermore, CCL11-induced phosphorylation of Akt was abolished by PI3K inhibitors. siRNA-mediated knockdown of CCR3 led to a significant reduction of PI3K phosphorylation. However, the phosphorylation levels of ERK1/2 were not changed, even after CCL11 treatment. Cumulatively, our data suggest that the CCL11-CCR3 interaction mainly activates PI3K/Akt signal transduction pathway in HUVECs.

Radiosensitization of the PI3K inhibitor HS-173 through reduction of DNA damage repair in pancreatic cancer.

Activation of PI3K/AKT pathway occurs frequently in tumors and is correlated with radioresistance. The PI3K/AKT pathway can be an important target for improvement of radiotherapy. Although adding of chemotherapy to radiation therapy regimen enhances survival in patients with locally advanced pancreatic cancer, more effective therapies for increasing radiosensitivity are urgently needed. In this study, we investigated whether the novel PI3K inhibitor HS-173 could attenuate radiation-induced up-regulation of DNA damage repair processes and assessed its efficacy as a radio- and chemo-sensitizer. Radiosensitizing effects of HS-173 were tested in human pancreatic cells using clonogenic survival and growth assays. Mechanisms underlying the effects of HS-173 and radiation were determined by assessing cell cycle and DNA damage- repair pathway components, including ataxia-telangiectasia mutated (ATM) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs). The in vivo efficacy of HS-173 in cancer radiotherapy was evaluated using a human tumor xenograft model. HS-173 significantly increased the sensitivity of pancreatic cancer cells to radiation, an effect that was associated with G2/M cell cycle arrest. HS-173 also significantly attenuated DNA damage repair by potently inhibiting ATM and DNA-PKcs, the two major kinases that respond to radiation-induced DNA double-strand breaks (DSBs), resulting in sustained DNA damage. Moreover, the combination of HS-173 and radiation delayed tumor growth and impaired DNA repair in a pancreatic cancer xenograft model, reflecting enhanced radiosensitization. These results showed that HS-173 significantly improved radiotherapy by inhibiting the DNA damage-repair pathway in pancreatic cancer. We therefore suggest that HS-173 may be an effective radiosensitizer for pancreatic cancer.

Relationship between dopamine deficit and the expression of depressive behavior resulted from alteration of serotonin system.

Depression frequently accompanies in Parkinson's disease (PD). Previous research suggested that dopamine (DA) and serotonin systems are closely linked with depression in PD. However, comprehensive studies about the relationship between these two neurotransmitter systems are limited. Therefore, the purpose of this study is to evaluate the effect of dopaminergic destruction on the serotonin system. The interconnection between motor and depression was also examined. Two PET scans were performed in the 6-hydroxydopamine (6-OHDA) lesioned and sham operated rats: [(18) F]FP-CIT for DA transporters and [(18) F]Mefway for serotonin 1A (5-HT(1A)) receptors. Here, 6-OHDA is a neurotoxin for dopaminergic neurons. Behavioral tests were used to evaluate the severity of symptoms: rotational number for motor impairment and immobility time, acquired from the forced swim test for depression. Region-of-interests were drawn in the striatum and cerebellum for the DA system and hippocampus and cerebellum for the 5-HT system. The cerebellum was chosen as a reference region. Nondisplaceable binding potential in the striatum and hippocampus were compared between 6-OHDA and sham groups. As a result, the degree of DA depletion was negatively correlated with rotational behavior (R(2) = 0.79, P = 0.003). In 6-OHDA lesioned rats, binding values for 5-HT(1A) receptors was 22% lower than the sham operated group. This decrement of 5-HT(1A) receptor binding was also correlated with the severity of depression (R(2) = 0.81, P = 0.006). Taken together, this research demonstrated that the destruction of dopaminergic system causes the reduction of the serotonergic system resulting in the expression of depressive behavior. The degree of dopaminergic dysfunction was positively correlated with the impairment of the serotonin system. Severity of motor symptoms was also closely related to depressive behavior.

Parkin induces G2/M cell cycle arrest in TNF-α-treated HeLa cells.

Parkin is a known tumor suppressor. However, the mechanism by which parkin acts as a tumor suppressor remains to be fully elucidated. Previously, we reported that parkin expression induces caspase-dependent apoptotic cell death in TNF-α-treated HeLa cells. However, at that time, we did not consider the involvement of parkin in cell cycle control. In the current study, we investigated whether parkin is involved in cell cycle regulation and suppression of cancer cell growth. In our cell cycle analyses, parkin expression induced G2/M cell cycle arrest in TNF-α-treated HeLa cells. To elucidate the mechanism(s) by which parkin induces this G2/M arrest, we analyzed cell cycle regulatory molecules involved in the G2/M transition. Parkin expression induced CDC2 phosphorylation which is known to inhibit CDC2 activity and cause G2/M arrest. Cyclin B1, which is degraded during the mitotic transition, accumulated in response to parkin expression, thereby indicating parkin-induced G2/M arrest. Next, we established that Myt1, which is known to phosphorylate and inhibit CDC2, increased following parkin expression. In addition, we found that parkin also induces increased Myt1 expression, G2/M arrest, and reduced cell viability in TNF-α-treated HCT15 cells. Furthermore, knockdown of parkin expression by parkin-specific siRNA decreased Myt1 expression and phosphorylation of CDC2 and resulted in recovered cell viability. These results suggest that parkin acts as a crucial molecule causing cell cycle arrest in G2/M, thereby suppressing tumor cell growth.