Cannabidiol enhances Atezolizumab efficacy by upregulating PD-L1 expression via the cGAS-STING pathway in triple-negative breast cancer cells.

The treatment of patients with triple negative breast cancer (TNBC) relies on cytotoxic therapy. Currently, atezolizumab and chemotherapy can be combined in patients with TNBC. However, this approach is not effective for all patients with low reactivity to atezolizumab. As there is a lack of alternative treatment options, new anti-cancer drugs are urgently needed to enhance atezolizumab reactivity against TNBC. Recent strategies have focused on regulating the expression of programmed death-ligand 1 (PD-L1) or enhancing immune response activation by combining anti-cancer drugs with immune checkpoint inhibitors (ICIs). Cannabidiol (CBD), a cannabinoid component derived from the cannabis plant, has been reported to have anti-cancer therapeutic potential because of its capacity to induce apoptotic cell death in tumor cells while avoiding cytotoxicity in normal cells. Previous studies have demonstrated the effects of CBD on apoptosis in various cancer cell types. However, the potential role of CBD as an immune modulator in the regulation of PD-L1 expression and anti-cancer immune responses remains to be explored. In this study, we found that CBD stimulated PD-L1 expression in TNBC cells, which significantly induced the CBD-mediated cGAS-STING pathway activation. Taken together, we demonstrated that the combination of CBD and anti-PD-L1 antibody enhances the anti-cancer immune response in vitro and in vivo experiments. Our findings identified the mechanism of PD-L1 regulation by CBD in TNBC cells and suggested that CBD could be a potential candidate for the development of new combinatorial strategies with ICIs in TNBC patients.

The Role of IRF9 Upregulation in Modulating Sensitivity to Olaparib and Platinum-Based Chemotherapies in Breast Cancer.

Poly(ADP-ribose) polymerase (PARP) inhibitors are targeted therapies that accumulate DNA damage by interfering with DNA repair mechanisms and are approved for treating several cancers with BRCA1/2 mutations. In this study, we utilized CRISPR-dCas9 interference screening to identify genes regulating sensitivity to PARP inhibitors in breast cancer cell lines. Our findings indicated that the interferon (IFN) signaling gene IRF9 was critically involved in modulating sensitivity to these inhibitors. We revealed that the loss of IRF9 leads to increased resistance to the PARP inhibitor in MDA-MB-468 cells, and a similar desensitization was observed in another breast cancer cell line, MDA-MB-231. Further analysis indicated that while the basal expression of IRF9 did not correlate with the response to the PARP inhibitor olaparib, its transcriptional induction was significantly associated with increased sensitivity to the DNA-damaging agent cisplatin in the NCI-60 cell line panel. This finding suggests a mechanistic link between IRF9 induction and cellular responses to DNA damage. Additionally, data from the METABRIC patient tissue study revealed a complex network of IFN-responsive gene expressions postchemotherapy, with seven upregulated genes, including IRF9, and three downregulated genes. These findings underscore the intricate role of IFN signaling in the cellular response to chemotherapy. Collectively, our CRISPR screening data and subsequent bioinformatic analyses suggest that IRF9 is a novel biomarker for sensitivity to DNA-damaging agents, such as olaparib and platinum-based chemotherapeutic agents. Our findings for IRF9 not only enhance our understanding of the genetic basis of drug sensitivity, but also elucidate the role of IRF9 as a critical effector within IFN signaling pathways, potentially influencing the association between the host immune system and chemotherapeutic efficacy.

Safe and successful pregnancy following breast cancer treatment in young patients 35 years old or under without invasive fertility preservation: a retrospective study.

Purpose: Recent advances in the treatment of breast cancer have led to the improvement of breast cancer patient's survival. With the prolonged survival of these patients, pregnancy became an important issue, especially in young cancer patient aged 35 years or under. Increased hormone levels during pregnancy, however, raise concerns about elevating the risk of cancer recurrence. The aim of this study was to validate the notion of increased risk associated with pregnancy after breast cancer treatment in young patients. Methods: From January 2009 to December 2020, newly diagnosed breast cancer patients 35 years old or under who underwent optimal surgery in Korea University Guro Hospital were enrolled in this study. Patients were categorized into 3 groups: nulliparous, pregnancy prior to treatment of breast cancer, and patients with pregnancy after breast cancer treatment. Their overall survival and disease-free survival were evaluated. Results: A total of 107 patients were enrolled in this study. Thirteen patients (12.1%) conceived and successfully delivered. The mean follow-up period after surgery was 58.9 (± 33.5) months. There was no significant difference in overall survival (P = 0.608) and disease-free survival (P = 0.591) among different groups. Conclusion: In young patients, pregnancy after treatment for breast cancer did not affect their overall survival or diseasefree survival as compared to nullipara or previously delivered groups. Therefore, pregnancy counseling should not be prevented in young breast cancer patients 35 years old or under.

Efficacy of a continuous wound infiltration system for postoperative pain management in gynecologic patients who underwent single-port access laparoscopy for adnexal disease.

Introduction: Single-port access (SPA) laparoscopy requires only one incision, unlike conventional laparoscopy. However, its umbilical incision is larger than that of conventional laparoscopy and can be vulnerable to postoperative pain. This study aimed to evaluate whether simultaneous use of a continuous wound infiltration (CWI) system and intravenous patient-controlled analgesia (IV PCA) effectively decreases surgical site pain in patients who underwent SPA laparoscopy due to gynecologic adnexal disease. Methods: A total of 371 patients who underwent SPA laparoscopy and who received IV PCA or CWI was retrospectively reviewed (combined group [CWI + IV PCA, n = 159] vs. PCA group [IV PCA only, n = 212]). To evaluate postoperative pain management, the numeric rating scale (NRS) pain score after surgery, total amount of fentanyl administered via IV PCA, and additional pain killer consumption were collected. Results: The NRS scores at 12 h (1.90 ± 1.11 vs. 2.70 ± 1.08, p < 0.001) and 24 h (1.82 ± 0.82 vs. 2.11 ± 1.44, p = 0.026) after surgery were significantly lower in the combined group than in the PCA group. The total amount of PCA fentanyl was significantly smaller in the combined group than in the PCA group (p < 0.001). The total quantity of rescue analgesics was smaller in the combined group than in the PCA group (p < 0.05). Conclusion: Combined use of the CWI system and IV PCA is an effective postoperative pain management strategy in patient who underwent SPA laparoscopy for adnexal disease.

Oncogenic Impact of TONSL, a Homologous Recombination Repair Protein at the Replication Fork, in Cancer Stem Cells.

We investigated the role of TONSL, a mediator of homologous recombination repair (HRR), in stalled replication fork double-strand breaks (DSBs) in cancer. Publicly available clinical data (tumors from the ovary, breast, stomach and lung) were analyzed through KM Plotter, cBioPortal and Qomics. Cancer stem cell (CSC)-enriched cultures and bulk/general mixed cell cultures (BCCs) with RNAi were employed to determine the effect of TONSL loss in cancer cell lines from the ovary, breast, stomach, lung, colon and brain. Limited dilution assays and ALDH assays were used to quantify the loss of CSCs. Western blotting and cell-based homologous recombination assays were used to identify DNA damage derived from TONSL loss. TONSL was expressed at higher levels in cancer tissues than in normal tissues, and higher expression was an unfavorable prognostic marker for lung, stomach, breast and ovarian cancers. Higher expression of TONSL is partly associated with the coamplification of TONSL and MYC, suggesting its oncogenic role. The suppression of TONSL using RNAi revealed that it is required in the survival of CSCs in cancer cells, while BCCs could frequently survive without TONSL. TONSL dependency occurs through accumulated DNA damage-induced senescence and apoptosis in TONSL-suppressed CSCs. The expression of several other major mediators of HRR was also associated with worse prognosis, whereas the expression of error-prone nonhomologous end joining molecules was associated with better survival in lung adenocarcinoma. Collectively, these results suggest that TONSL-mediated HRR at the replication fork is critical for CSC survival; targeting TONSL may lead to the effective eradication of CSCs.

Dual Impact of IGF2 on Alveolar Stem Cell Function during Tobacco-Induced Injury Repair and Development of Pulmonary Emphysema and Cancer.

Pulmonary emphysema is a destructive inflammatory disease primarily caused by cigarette smoking (CS). Recovery from CS-induced injury requires proper stem cell (SC) activities with a tightly controlled balance of proliferation and differentiation. Here we show that acute alveolar injury induced by two representative tobacco carcinogens, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and benzo[a]pyrene (N/B), increased IGF2 expression in alveolar type 2 (AT2) cells to promote their SC function and facilitate alveolar regeneration. Autocrine IGF2 signaling upregulated Wnt genes, particularly Wnt3, to stimulate AT2 proliferation and alveolar barrier regeneration after N/B-induced acute injury. In contrast, repetitive N/B exposure provoked sustained IGF2-Wnt signaling through DNMT3A-mediated epigenetic control of IGF2 expression, causing a proliferation/differentiation imbalance in AT2s and development of emphysema and cancer. Hypermethylation of the IGF2 promoter and overexpression of DNMT3A, IGF2, and the Wnt target gene AXIN2 were seen in the lungs of patients with CS-associated emphysema and cancer. Pharmacologic or genetic approaches targeting IGF2-Wnt signaling or DNMT prevented the development of N/B-induced pulmonary diseases. These findings support dual roles of AT2 cells, which can either stimulate alveolar repair or promote emphysema and cancer depending on IGF2 expression levels. SIGNIFICANCE: IGF2-Wnt signaling plays a key role in AT2-mediated alveolar repair after cigarette smoking-induced injury but also drives pathogenesis of pulmonary emphysema and cancer when hyperactivated.

Sarcoid Heart Disease: Review of Current Knowledge.

Sarcoidosis is a granulomatous disease with the potential of multiple organ system involvement and its etiology remains unknown. Cardiac involvement is associated with worse clinical outcome, and has been reported to be 20-30% in white and as high as 58% in Japanese populations with sarcoidosis. Clinical manifestations of cardiac sarcoidosis highly depend on the extent and location of granulomatous inflammation. The most frequent presentations include heart block, tachyarrhythmia, or heart failure. Endomyocardial biopsy is the most specific diagnostic test, but has poor sensitivity due to often patchy involvement. The diagnosis of cardiac sarcoidosis remains challenging due to nonspecific imaging findings. Both 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and cardiac magnetic resonance imaging can be used to evaluate cardiac sarcoidosis, but evaluate different stages of the disease process. FDG-PET detects metabolically active inflammatory cells while cardiac magnetic resonance imaging with late gadolinium enhancement reveals areas of myocardial necrosis and fibrosis. Aggressive therapy of symptomatic cardiac sarcoidosis is often sought due to the high risk of sudden death and/or progression to heart failure. Prednisone 20-40 mg a day is the recommended initial treatment. In refractory or severe cases, higher doses of prednisone, 1-1.5 mg/kg/d (or its equivalent) and addition of a steroid-sparing agent have been utilized. Methotrexate is added most commonly. Long-term improvement has been reported with the use of a combination of weekly methotrexate and prednisone versus prednisone alone. After initiation of treatment, a cardiac FDG-PET scan may be performed 2-3 months later to assess treatment response.

Screening of the siGPCR library in combination with cisplatin against lung cancers.

The screening of siRNAs targeting 390 human G protein-coupled receptors (GPCRs) was multiplexed in combination with cisplatin against lung cancer cells. While the cell viability measure hardly captured the anticancer effect of siGPCRs, the direct cell count revealed the anticancer potential of diverse GPCRs (46 hits with > twofold growth inhibition, p-value < 0.01). In combined treatment with cisplatin, siRNAs against five genes (ADRA2A, F2RL3, NPSR1, NPY and TACR3) enhanced the anti-proliferation efficacy on cancer cells and reduced the self-recovery ability of surviving cells after the removal of the combined treatment. Further on-target validation confirmed that the knockdown of TACR3 expression exhibited anticancer efficacy under both single and combined treatment with cisplatin. Q-omics ( http://qomics.io ) analysis showed that high expression of TACR3 was unfavorable for patient survival, particularly with mutations in GPCR signaling pathways. The present screening data provide a useful resource for GPCR targets and biomarkers for improving the efficacy of cisplatin treatment.

Under- and Normal-Weight Patients Are More Susceptible to Recurrence of Phyllodes Tumor.

Purpose: Phyllodes tumors (PTs) of the breast are rare fibroepithelial neoplasms, and factors associated with the recurrence of PTs are poorly understood. This study sought to identify clinicopathological factors associated with the recurrence of PTs. Method: From January 2009 to December 2019, we identified 100 patients who underwent definitive surgery for PT. Clinicopathological risk factors associated with the recurrence of PT were assessed. Results: The median age of the patients was 44 y (range, 19-62 y), and the median tumor size was 4 cm (0.8-30 cm). At a median follow-up of 26.7 mo (0-103 mo), 22 of the 100 patients experienced local recurrence. In the univariate and multivariate analyses, body mass index ≥ 23 kg/m2 (P = 0.042 in the univariate analysis; P = 0.039 in the multivariate analysis), tumor size ≥ 5 cm (P = 0.006 in the univariate analysis; P = 0.036 in the multivariate analysis), and the presence of stromal overgrowth (P = 0.032 in the univariate analysis; P = 0.040 in the multivariate analysis) were associated with an increased risk of local recurrence. Resection margins and grade were not associated with local recurrence. Conclusion: Normal- or underweight patients and those with larger tumor sizes were more prone to local recurrence. Further larger, multicenter studies with a long-term follow-up are required.

ARL2 is required for homologous recombination repair and colon cancer stem cell survival.

ARL2 regulates the dynamics of cytological components and is highly expressed in colon cancer tissues. Here, we report novel roles of ARL2 in the cell nucleus and colon cancer stem cells (CSCs). ARL2 is expressed at relatively low levels in K-RAS active colon cancer cells, but its expression is induced in CSCs. Depletion of ARL2 results in M phase arrest exclusively in non-CSC cultured cells; in addition, DNA break stress accumulates in CSCs leading to apoptosis. ARL2 expression is positively associated with the expression of all six RAD51 family genes, which are essential for homologous recombination repair (HRR). Furthermore, ARL2 is required for HRR and detected within chromatin compartments. These results demonstrate the requirement of ARL2 in colon CSC maintenance, which possibly occurs through mediating double-strand break DNA repair in the nucleus.

Human-robot-robot cooperative control using positioning robot and 1-DOF traction device for robot-assisted fracture reduction system.

While performing musculoskeletal long bone fracture reduction surgery, assistant surgeons can often suffer from physical fatigue as they provide resistance against the tension from surrounding muscles pulling on the patient's broken bones. These days, robotic systems are being actively developed to mitigate this physical workload by realigning and holding these fractured bones for surgeons. This has led to one consortium proposing the development of a robot-assisted fracture reduction system consisting of a 6-DOF positioning robot along with a 1-DOF traction device. With the introduction of the 1-DOF traction device, the positioning robot does not have to fight these contraction forces so can be compact improving its maneuverability and overall convenience; however, considering surgeon-robot interactions, this approach adds the requirement of controlling two different types of robots simultaneously. As such, an advanced cooperative control methodology is required to control the proposed bone fracture reduction robot system. In this paper, a human-robot-robot cooperative control (HRRCC) scheme is proposed for collaboration between the surgeon, the positioning robot, and the traction device. First, the mathematical background of this HRRCC scheme is provided. Next, we describe a series of experiments that show how the proposed scheme facilitates a reduction in the load placed on the positioning robot from strong muscular contraction forces making it possible to conduct fracture reduction procedures more safely despite the muscular forces.

Cannabidiol Suppresses Angiogenesis and Stemness of Breast Cancer Cells by Downregulation of Hypoxia-Inducible Factors-1α.

To assess the effect of Cannabidiol (CBD) on the angiogenesis and stemness of breast cancer cells as well as proliferation. Methods: mRNA level and the amount of protein of vascular endothelial growth factor (VEGF) were determined by qRT-PCR and ELISA. The angiogenic potential of breast cancer cells under hypoxic conditions was identified by the HUVEC tube formation assay. The degradation of HIF-1α by CBD and the Src/von Hippel-Lindau tumor suppressor protein (VHL) interaction were assessed by a co-immunoprecipitation assay and Western blotting. To identify the stemness of mamospheres, they were evaluated by the sphere-forming assay and flow cytometry. Results: CBD can suppress angiogenesis and stem cell-like properties of breast cancer through Src/VHL/HIF-1α signaling. CBD may potentially be utilized in the treatment of refractory or recurrent breast cancer.

Microstructured Surfaces for Reducing Chances of Fomite Transmission via Virus-Containing Respiratory Droplets.

Evaporation-induced particle aggregation in drying droplets is of significant importance in the prevention of pathogen transfer due to the possibility of indirect fomite transmission of the infectious virus particles. In this study, particle aggregation was directionally controlled using contact line dynamics (pinned or slipping) and geometrical gradients on microstructured surfaces by the systematic investigation of the evaporation process on sessile droplets and sprayed microdroplets laden with virus-simulant nanoparticles. Using this mechanism, we designed robust particle capture surfaces by significantly inhibiting the contact transfer of particles from fomite surfaces. For the proof-of-concept, interconnected hexagonal and inverted pyramidal microwall were fabricated using ultraviolet-based nanoimprint lithography, which is considered to be a promising scalable manufacturing process. We demonstrated the potentials of an engineered microcavity surface to limit the contact transfer of particle aggregates deposited with the evaporation of microdroplets by 93% for hexagonal microwall and by 96% for inverted pyramidal microwall. The particle capture potential of the interconnected microstructures was also investigated using biological particles, including adenoviruses and lung-derived extracellular vesicles. The findings indicate that the proposed microstructured surfaces can reduce the indirect fomite transmission of highly infectious agents, including norovirus, rotavirus, or SARS-CoV-2, via respiratory droplets.

A novel synthetic microtubule inhibitor exerts antiproliferative effects in multidrug resistant cancer cells and cancer stem cells.

The success of cancer chemotherapy is limited by multidrug resistance (MDR), which is mainly caused by P-glycoprotein (P-gp) overexpression. In the present study, we describe a novel microtubule inhibitor, 5-(N-methylmaleimid-3-yl)-chromone (SPC-160002), that can be used to overcome MDR. A synthetic chromone derivative, SPC-160002, showed a broad spectrum of anti-proliferative effects on various human cancer cells without affecting P-gp expression and its drug efflux function. Treatment with SPC-160002 arrested the cell cycle at the M phase, as evidenced using fluorescence-activated cell sorting analysis, and increased the levels of mitotic marker proteins, including cyclin B, pS10-H3, and chromosomal passenger complex. This mitotic arrest by SPC-160002 was mediated by promoting and stabilizing microtubule polymerization, similar to the mechanism observed in case of taxane-based drugs. Furthermore, SPC-160002 suppressed the growth and sphere-forming activity of cancer stem cells. Our data herein strongly suggest that SPC-160002, a novel microtubule inhibitor, can be used to overcome MDR and can serve as an attractive candidate for anticancer drugs.

Desmoid type fibromatosis of the distal pancreas: A case report.

A 23-year-old Korean female presented epigastric pain of two-months' duration. She had a laparoscopic ovarian cyst excision 8 months previously. Clinical examination was normal. An abdominal computed tomogram (CT) demonstrated a 10-cm solid mass in the distal pancreas, with signs of splenic artery and vein occlusion, gastric and transverse colon invasion. Operative findings showed a mass involving distal pancreas, invasive to the posterior wall of the antrum of the stomach and transverse colon and 4th portion of the duodenum without lymph node involvement. The surgery consisted of a distal pancreatectomy, splenectomy and combined partial resection of the stomach, transverse colon and 4th portion of the duodenum. The immunohistochemistry and histopathological features were consistent with a confirmed diagnosis of intra-abdominal desmoid type fibromatosis (DTF). The prognosis of pancreatic DTF is not known and she showed no recurrence or distant metastasis during a 3 year follow-up. Herein we report a rare case with an isolated, sporadic, and non-trauma-related DTF, located at the pancreatic body and tail.

Comparison of Single Incision Endoscopic Nipple-Sparing Mastectomy and Conventional Nipple-Sparing Mastectomy for Breast Cancer Based on Initial Experience.

PURPOSE: Endoscopic breast surgery for patients with breast cancer was introduced for its superior cosmetic outcomes; it was initially studied in the field of breast-conserving surgery and, more recently, in robotic-assisted nipple-sparing mastectomy (NSM). The main purpose of this study was to investigate the feasibility and safety of endoscopic NSM (E-NSM) in patients with breast cancer by comparing E-NSM and conventional NSM (C-NSM). METHODS: Between May 2017 and October 2020, we retrieved the records of 45 patients who underwent NSM with permanent silicone implants and divided them into the E-NSM group (20 patients) and the C-NSM group (25 patients), depending on the use of the endoscopic device. We also analyzed demographic information, pathology, operative time, and complications. RESULTS: No significant differences were observed between the 2 groups based on demographic information, postoperative pathological data, mean length of hospital stay, and total number of complications. The mean preparation time for surgery was comparable between both groups. Compared to the C-NSM group, the E-NSM group had a significantly longer mean operative time and, subsequently, a significantly longer mean total operative time and number of complications. CONCLUSION: The results showed that E-NSM was feasible and safe with a more inconspicuous incision in patients with breast cancer.

Detailed comparison of the da Vinci Xi and S surgical systems for transaxillary thyroidectomy.

ABSTRACT: Robotic surgical systems have evolved over time. The da Vinci Xi system was developed in 2014 and was expected to solve the shortcomings of the previous S system. Therefore, we conducted this study to compare these 2 systems and identify if the Xi system truly improves surgical outcomes.In this retrospective study, a total of 86 patients with unilateral papillary thyroid carcinoma without central lymph node involvement underwent gasless transaxillary hemithyroidectomy using 2 robotic systems, the da Vinci S and Xi. Forty patients were in the da Vinci S group and 46 patients were in the da Vinci Xi group. All surgeries were performed by 1 surgeon (YWC). All surgery video files were analyzed to compare the duration of each surgical step.The total operation time was significantly shorter in the Xi group than in the S group (153.0 minutes vs 105.7 minutes, P < .01). Time for robot docking was shorter in the Xi group (19.8 minutes vs 10.6 minutes, P < .01), and all procedures performed in the console also required a shorter time in this group. The overall complication rate did not differ significantly (P = .464).The da Vinci Xi system made robotic thyroidectomy easier and faster without increasing the complication rate. It is a safe and valuable system for robotic thyroidectomy.

Species Prioritization Based on Spectral Dissimilarity: A Case Study of Polyporoid Fungal Species.

Biological species collections are critical for natural product drug discovery programs. However, prioritization of target species in massive collections remains difficult. Here, we introduce an untargeted metabolomics-based prioritization workflow that uses MS/MS molecular networking to estimate scaffold-level distribution. As a demonstration, we applied the workflow to 40 polyporoid fungal species. Nine species were prioritized as candidates based on the chemical structural and compositional similarity (CSCS) metric. Most of the selected species showed relatively higher richness and uniqueness of metabolites than those of the others. Cryptoporus volvatus, one of the prioritized species, was investigated further. The chemical profiles of the extracts of C. volvatus culture and fruiting bodies were compared, and it was shown that derivative-level diversity was higher in the fruiting bodies; meanwhile, scaffold-level diversity was similar. This showed that the compounds found from a cultured fungus can also be isolated in wild mushrooms. Targeted isolation of the fruiting body extract yielded three unknown (1-3) and six known (4-9) cryptoporic acid derivatives, which are drimane-type sesquiterpenes with isocitric acid moieties that have been reported in this species. Cryptoporic acid T (1) is a trimeric cryptoporic acid reported for the first time. Compounds 2 and 5 exhibited cytotoxicity against HCT-116 cell lines with IC50 values of 4.3 and 3.6 µM, respectively.

Targeting a Lipid Desaturation Enzyme, SCD1, Selectively Eliminates Colon Cancer Stem Cells through the Suppression of Wnt and NOTCH Signaling.

The elimination of the cancer stem cell (CSC) population may be required to achieve better outcomes of cancer therapy. We evaluated stearoyl-CoA desaturase 1 (SCD1) as a novel target for CSC-selective elimination in colon cancer. CSCs expressed more SCD1 than bulk cultured cells (BCCs), and blocking SCD1 expression or function revealed an essential role for SCD1 in the survival of CSCs, but not BCCs. The CSC potential selectively decreased after treatment with the SCD1 inhibitor in vitro and in vivo. The CSC-selective suppression was mediated through the induction of apoptosis. The mechanism leading to selective CSC death was investigated by performing a quantitative RT-PCR analysis of 14 CSC-specific signaling and marker genes after 24 and 48 h of treatment with two concentrations of an inhibitor. The decrease in the expression of Notch1 and AXIN2 preceded changes in the expression of all other genes, at 24 h of treatment in a dose-dependent manner, followed by the downregulation of most Wnt- and NOTCH-signaling genes. Collectively, we showed that not only Wnt but also NOTCH signaling is a primary target of suppression by SCD1 inhibition in CSCs, suggesting the possibility of targeting SCD1 against colon cancer in clinical settings.

Identification and functional study of genetic polymorphisms in cyclic nucleotide phosphodiesterase 3A (PDE3A).

Phosphodiesterase 3A (PDE3A) is an enzyme that plays an important role in the regulation of cyclic adenosine monophosphate (cAMP)-mediated intracellular signaling in cardiac myocytes and platelets. PDE3A hydrolyzes cAMP, which results in a decrease in intracellular cAMP levels and leads to platelet activation. Whole-exome sequencing of 50 DNA samples from a healthy Korean population revealed a total of 13 single nucleotide polymorphisms including five missense variants, D12N, Y497C, H504Q, C707R, and A980V. Recombinant proteins for the five variants of PDE3A (and wild-type protein) were expressed in a FreeStyle 293 expression system with site-directed mutagenesis. The expression of the recombinant PDE3A proteins was confirmed with Western blotting. Catalytic activity of the PDE3A missense variants and wild-type enzyme was measured with a PDE-based assay. Effects of the missense variants on the inhibition of PDE3A activity by cilostazol were also investigated. All variant proteins showed reduced activity (33-53%; p < .0001) compared to the wild-type protein. In addition, PDE3A activity was inhibited by cilostazol in a dose-dependent manner and was further suppressed in the missense variants. Specifically, the PDE3A Y497C showed significantly reduced activity, consistent with the predictions of in silico analyses. The present study provides evidence that individuals carrying the PDE3A Y497C variant may have lower enzyme activity for cAMP hydrolysis, which could cause interindividual variation in cAMP-mediated physiological functions.