Importance of duodenal stump reinforcement to prevent stump leakage after gastrectomy: a large-scale multicenter retrospective study (KSCC DELICATE study).

BACKGROUND: The significance of reinforcement of the duodenal stump with seromuscular sutures and the effectiveness of reinforced staplers in preventing duodenal stump leakage remain unclear. We aimed to explore the importance of duodenal stump reinforcement and determine the optimal reinforcement method for preventing duodenal stump leakage. METHODS: This retrospective cohort study was conducted between January 1, 2012 and December 31, 2021, with data analyzed between December 1, 2022 and September 30, 2023. This multicenter study across 57 institutes in Japan included 16,475 patients with gastric cancer who underwent radical gastrectomies. Elective open or minimally invasive (laparoscopic or robotic) gastrectomy was performed in patients with gastric cancer. RESULTS: Duodenal stump leakage occurred in 153 (0.93%) of 16,475 patients. The proportions of males, patients aged ≥ 75 years, and ≥ pN1 were higher in patients with duodenal stump leakage than in those without duodenal stump leakage. The incidence of duodenal stump leakage was significantly lower in the group treated with reinforcement by seromuscular sutures or using reinforced stapler than in the group without reinforcement (0.72% vs. 1.19%, p = 0.002). Duodenal stump leakage incidence was also significantly lower in high-volume institutions than in low-volume institutions (0.70% vs. 1.65%, p = 0.047). The rate of duodenal stump leakage-related mortality was 7.8% (12/153). In the multivariate analysis, preoperative asthma and duodenal invasion were identified as independent preoperative risk factors for duodenal stump leakage-related mortality. CONCLUSIONS: The duodenal stump should be reinforced to prevent duodenal stump leakage after radical gastrectomy in patients with gastric cancer.

Risk Factor of Sarcopenia After Gastrectomy in Elderly Patients With Gastric Cancer.

BACKGROUND/AIM: Sarcopenia is a progressive and generalized muscle disorder correlated with an increased risk of adverse outcomes, including falls, fractures, physical disability and mortality. Moreover, sarcopenia is associated with short- and long-term outcomes after surgery in patients with gastrointestinal malignancies. Additionally, severe skeletal muscle loss after surgery reduces quality of life. In this study, we analyzed the perioperative risk factors for skeletal muscle loss after gastrectomy in elderly patients undergoing radical gastrectomy for gastric cancer. PATIENTS AND METHODS: In this case-control study, we enrolled patients aged ≥75 years who underwent radical gastrectomy for gastric cancer between January 2014 and December 2020 at our Institution. The psoas muscle index was used to assess skeletal muscle mass. They were divided into two groups-muscle depletion (D group) and no depletion (ND group)-depending on the ratio of skeletal muscle loss before and after gastrectomy. RESULTS: The D and ND groups comprised 34 and 41 patients, respectively. Univariate analysis showed that open gastrectomy was a potential risk factor for postoperative skeletal muscle loss in elderly gastric cancer patients (p=0.017). In multiple logistic regression analysis using the following variables: sex, operation and approach, the D group had a significantly higher proportion of patients who underwent open surgery than the ND group (p=0.032). CONCLUSION: Open gastrectomy is an independent risk factor for the progression of sarcopenia after gastrectomy in elderly patients with gastric cancer. Laparoscopic surgery is an eligible method for preserving skeletal muscle mass in elderly patients with gastric cancer.

Postoperative hiatal hernia after minimally invasive esophagectomy for esophageal cancer.

BACKGROUND: Minimally invasive esophagectomy (MIE) can reduce various complications compared with conventional thoracotomic esophagectomy. However, several reports suggested that MIE promoted incidence of post-operative hiatal hernia (HH). In current reports, we retrospectively analyzed incidence and risk factors of HH development after MIE. METHODS: A total of 113 patients undergoing MIE (McKeown esophagectomy) at our institute from April 2009 to December 2015 were included in this study. Patients with clinical stage II and III received neoadjuvant chemotherapy (NAC). RESULTS: Eleven of 113 patients (9.7%) undergoing MIE developed HH. Four of them were female and the ratio of female among the patient with HH was higher than that among the patient without HH after MIE (36.4% vs. 13.7%, P=0.05). Sixty-six patients (58.4%) during the study period were administered NAC and 10 of 11 patients with HH (90.9%) received NAC according to the clinical stage, which was significantly more than in the non-HH group (P=0.02). Type and route of graft organ were not related to HH development. Moreover, the fixation of the conduit organ at the hiatus does not contribute to post-operative HH. CONCLUSIONS: In the current study, we showed that NAC was a major risk factor of HH development after MIE.

Molecular cloning of putative chloroplastic cysteine synthase in Leucaena leucocephala.

Cysteine biosynthesis is directed by the successive commitments of serine acetyltransferase, and O-acetylserine (thiol) lyase (OASTL) compounds, which subsequently frame the decameric cysteine synthase complex. The isoforms of OASTL are found in three compartments of the cell: the cytosol, plastid, and mitochondria. In this investigation, we first isolated putative chloroplastic OASTL (Ch-OASTL) from Leucaena leucocephala, and the Ch-OASTL was then expressed in BL21-competent Escherichia coli. The putative Ch-OASTL cDNA clone had 1,543 base pairs with 391 amino acids in its open reading frame and a molecular weight of 41.54 kDa. The purified protein product exhibited cysteine synthesis ability, but not mimosine synthesis activity. However, they both make the common α-aminoacrylate intermediate in their first half reaction scheme with the conventional substrate O-acetyl serine (OAS). Hence, we considered putative Ch-OASTL a cysteine-specific enzyme. Kinetic studies demonstrated that the optimum pH for cysteine synthesis was 7.0, and the optimum temperature was 40 °C. In the cysteine synthesis assay, the Km and kcat values were 838 ± 26 µM and 72.83 s-1 for OAS, respectively, and 60 ± 2 µM and 2.43 s-1 for Na2S, respectively. We can infer that putative Ch-OASTL regulatory role is considered a sensor for sulfur constraint conditions, and it acts as a forerunner of various metabolic compound molecules.

Incidence of postoperative complications in transabdominal preperitoneal repair for groin hernia is influenced by poor performance status rather than by old age.

AIM: The present study was designed to evaluate the safety and feasibility of transabdominal preperitoneal (TAPP) repair for very old patients with groin hernia and to identify the risk factors predicting perioperative complications. METHODS: A total of 140 patients treated by TAPP were reviewed retrospectively. They were divided into two groups: patients ≥80 years of age (≥80 years group; n = 26) and those <80 years of age (<80 years group; n = 114). Patient characteristics and surgical outcomes were then statistically compared between the two groups. RESULTS: Number of patients with any comorbidities was significantly higher in the ≥80 years group than in the <80 years group (96.2% vs 61.4%, P = 0.003). There were no significant differences in surgical outcomes between the two groups. In the univariate analysis of perioperative complications, poor performance status (PS) (P = 0.014), lower hemoglobin level (P = 0.038) and lower albumin level (P = 0.016) were significantly associated with the occurrence of postoperative complications, and multivariate analysis showed that only poor PS was an independent factor (PS 0-2 vs 3-4: P = 0.034, OR 5.192 [95% CI; 1.137 to 23.71]). CONCLUSIONS: This is the first report to show that the incidence of postoperative complications in TAPP repair for groin hernia is influenced by poor PS rather than old age. TAPP can be a safe surgical procedure for very old patients with a good PS, with benefits that are equal to those in young patients.

Formalin fixation on HER-2 and PD-L1 expression in gastric cancer: A pilot analysis using the same surgical specimens with different fixation times.

BACKGROUND: The needs for human epidermal growth factor receptor 2 (HER-2) and/or programmed death-ligand 1 (PD-L1) evaluations in gastric cancer are dramatically increasing. Although the importance of standardization of sample fixation has been widely recognized, most of the evidence regarding the fixation duration or type of fixing solution are based on breast cancer. AIM: To investigate the real effects of fixation conditions on HER-2 testing or PD-L1 testing for gastric cancer using gastrectomy specimens. METHODS: Thirty-two patients who underwent gastrectomy for gastric cancer were enrolled. Their resected specimens were each divided into four pieces and fixed in four strictly controlled different durations (6 h, 24 h, and 48 h, and 1 wk) by 10% formalin (n = 22) or 10% neutral buffered formalin (NBF) (n = 10). Immunohistochemistry (IHC) of HER-2 and PD-1 was performed, and a pathology examination was conducted. In the HER-2-immunoreactive cases, all four specimens were subjected to dual-color in situ hybridization (DISH). Five cases were assessed as HER-2-positive by IHC and DISH. We used the cut-off values of 1%, 10%, and 50% to assess the IHC findings of PD-L1. RESULTS: No significant difference was observed in comparisons between the shorter fixation period groups (6 h, 24 h, and 48 h) and the prolonged fixation period (1 wk) group in the HER-2 and PD-L1 analyses. Although no significant difference was observed between 10% formalin and 10% NBF within 1 wk of fixation, the superiority of 10% NBF was confirmed in a long-term (> 3 mo) fixation in both the HER-2 and PD-L1 analyses. CONCLUSION: In this small-numbered pilot study, prolonged fixation within 1 wk showed no inferiority in HER-2 or PD-L1 testing. However, a large-numbered prospective study is needed to obtain conclusive results.

Molecular regulatory mechanism of isoprene emission under short-term drought stress in the tropical tree Ficus septica.

Isoprene is emitted by many plants and is thought to function as an antioxidant under stressful conditions. However, the detailed regulatory mechanism of isoprene emission in relation to the antioxidant system remains unclear. Therefore, in this study, we explored the molecular regulatory mechanism of isoprene emission under short-term drought stress in the tropical tree Ficus septica Burm.f. We found that the soil moisture content gradually decreased from 55% on Day 1 (D1) to 23% (wilting point) on D5 after withholding water for 4 days and then returning to the initial level following re-watering on D6. On D5, drought-stressed plants had more than twofold higher isoprene emission and 90.6% lower photosynthesis rates, 99.5% lower stomatal conductance and 82.3% lower transpiration rates than well-watered control plants. It was also estimated that the isoprene concentration inside the leaf greatly increased on D5 due to the increased isoprene emission rate and reduced stomatal conductance. Among the traits related to the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway, which is responsible for isoprene biosynthesis, the isoprene synthase (IspS) protein level was positively correlated with the isoprene emission rate in stressed plants. The transcripts of the antioxidant genes peroxidase 2 (POD2), POD4, copper-zinc superoxide dismutase 2 (Cu-ZnSOD2) and manganese superoxide dismutase 1 (Mn-SOD1) also increased during the drying period, while those of ascorbate peroxidase 1 (APX1) decreased. However, there was only a weak correlation between isoprene emission and antioxidant enzyme gene expression, indicating that the regulation of isoprene biosynthesis is not directly linked to the antioxidant defense network in drought-stressed F. septica. These findings suggest that the post-transcriptional regulation of IspS led to the observed change in isoprene emission rate, which enhanced the quenching of reactive oxygen species (ROS) and, in combination with the increased antioxidant enzyme activity, conferred tolerance to drought stress in this species.

Cytosolic Cysteine Synthase Switch Cysteine and Mimosine Production in Leucaena leucocephala.

In higher plants, multiple copies of the cysteine synthase gene are present for cysteine biosynthesis. Some of these genes also have the potential to produce various kinds of ß-substitute alanine. In the present study, we cloned a 1275-bp cDNA for cytosolic O-acetylserine(thiol)lyase (cysteine synthase) (Cy-OASTL) from Leucaena leucocephala. The purified protein product showed a dual function of cysteine and mimosine synthesis. Kinetics studies showed pH optima of 7.5 and 8.0, while temperature optima of 40 and 35 °C, respectively, for cysteine and mimosine synthesis. The kinetic parameters such as apparent Km, kcat were determined for both cysteine and mimosine synthesis with substrates O-acetylserine (OAS) and Na2S or 3-hydroxy-4-pyridone (3H4P). From the in vitro results with the common substrate OAS, the apparent kcat for Cys production is over sixfold higher than mimosine synthesis and the apparent Km is 3.7 times lower, suggesting Cys synthesis is the favored pathway.

Molecular characterization of cytosolic cysteine synthase in Mimosa pudica.

In the cysteine and mimosine biosynthesis process, O-acetyl-L-serine (OAS) is the common substrate. In the presence of O-acetylserine (thiol) lyase (OASTL, cysteine synthase) the reaction of OAS with sulfide produces cysteine, while with 3-hydroxy-4-pyridone (3H4P) produces mimosine. The enzyme OASTL can either catalyze Cys synthesis or both Cys and mimosine. A cDNA for cytosolic OASTL was cloned from M. pudica for the first time containing 1,410 bp nucleotides. The purified protein product from overexpressed bacterial cells produced Cys only, but not mimosine, indicating it is Cys specific. Kinetic studies revealed that pH and temperature optima for Cys production were 6.5 and 50 °C, respectively. The measured Km, Kcat, and Kcat Km-1 values were 159 ± 21 µM, 33.56 s-1, and 211.07 mM-1s-1 for OAS and 252 ± 25 µM, 32.99 s-1, and 130.91 mM-1s-1 for Na2S according to the in vitro Cys assay. The Cy-OASTL of Mimosa pudica is specific to Cys production, although it contains sensory roles in sulfur assimilation and the reduction network in the intracellular environment of M. pudica.

Tumor-Selective Cytotoxicity of Nitidine Results from Its Rapid Accumulation into Mitochondria.

We identified a nitidine- (NTD-) accumulating organelle and evaluated the net cytotoxicity of accumulated NTD. To evaluate tumor cell selectivity of the drug, we evaluated its selective cytotoxicity against 39 human cancer cell lines (JFCR39 panel), and the profile was compared with those of known anticancer drugs. Organelle specificity of NTD was visualized using organelle-targeted fluorescent proteins. Real-time analysis of cell growth, proliferation, and cytotoxicity was performed using the xCELLigence system. Selectivity of NTD in the JFCR39 panel was evaluated. Mitochondria-specific accumulation of NTD was observed. Real-time cytotoxicity analysis suggested that the mechanism of NTD-induced cell death is independent of the cell cycle. Short-term treatment indicated that this cytotoxicity only resulted from the accumulation of NTD into the mitochondria. The results from the JFCR39 panel indicated that NTD-mediated cytotoxicity resulted from unique mechanisms compared with those of other known anticancer drugs. These results suggested that the cytotoxicity of NTD is only induced by its accumulation in mitochondria. The drug triggered mitochondrial dysfunction in less than 2 h. Similarity analysis of the selectivity of NTD in 39 tumor cell lines strongly supported the unique tumor cell specificity of NTD. Thus, these features indicate that NTD may be a promising antitumor drug for new combination chemotherapies.

Temperature controls on the basal emission rate of isoprene in a tropical tree Ficus septica: exploring molecular regulatory mechanisms.

Isoprene emission from plants is very sensitive to environmental temperature both at short-term and long-term scales. Our previous study demonstrated suppression of isoprene emission by cold temperatures in a high emitting tropical tree Ficus septica and revealed a strong correlation of emission to isoprene synthase (IspS) protein levels. When challenged with decreasing daily temperatures from 30 to 12 °C, F. septica completely stopped isoprene emission at 12 °C, only to recover on the second day after re-exposure to 30 °C. Here, we explored this regulation of isoprene emission in response to environmental temperature by a comprehensive analysis of transcriptome data, gene expressions and metabolite pools of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway. MEP pathway genes and metabolites dynamics did not support substrate-level limitations as major control over observed basal emission, but transcriptome data, network inferences and putative regulatory elements on IspS promoter suggested transcriptional regulation of IspS gene through circadian rhythm and phytohormone signalling processes. Expression levels of 29 genes involved in these pathways were examined by quantitative real-time PCR. We propose that temperature controls over basal isoprene emission at a time-scale of hours to few days are regulated by phytohormone-mediated transcriptional modulation of IspS gene under synchronization by the circadian clock.

Pteryxin: a coumarin in Peucedanum japonicum Thunb leaves exerts antiobesity activity through modulation of adipogenic gene network.

OBJECTIVES: Partially purified hexane phase (HP) of Peucedanum japonicum Thunb (PJT) was identified as an antiobesity candidate. However, the compound responsible for the antiobesity activity remained unknown. Thus, in this study we isolated the active compound, to determine the mechanisms related to antiobesity activity in vitro. METHODS: The HP was fractionated, and the effect on the triacylglycerol (TG) content was evaluated in 3T3-L1 preadipocytes and HepG2 hepatocytes. On the basis of comprehensive spectroscopic analyses, the structure of the active compound was identified as pteryxin, a known compound in PJT. However, to our knowledge, its biological activities against obesity have not been reported previously. The dose-dependent effect on the TG content, and the gene expressions related to adipogenesis, fatty acid catabolism, energy expenditure, lipolysis, and lipogenesis due to pteryxin (10, 15, and 20 µg/mL) were examined in vitro. RESULTS: Pteryxin dose dependently suppressed TG content in both 3T3-L1 adipocytes (by 52.7%, 53.8%, and 57.4%, respectively; P < 0.05) and HepG2 hepatocytes (by 25.2%, 34.1%, and 27.4%, respectively; P < 0.05). Sterol regulatory element-binding protein-1 (SREBP-1c), fatty acid synthase (FASN), and acetyl-coenzyme A carboxylase-1 (ACC1) were down-regulated in pteryxin-treated 3T3-L1 adipocytes (by 18%, 36.1%, and 38.2%, P < 0.05) and HepG2 hepatocytes (by 72.3%, 62.9%, and 38.8%, respectively; P < 0.05). The adipocyte size marker gene, paternally expressed gene1/mesoderm specific transcript (MEST) was down-regulated (by 42.8%; P < 0.05), and hormone-sensitive lipase, a lipid catabolizing gene was up-regulated (by 15.1%; P < 0.05) in pteryxin-treated adipocytes. The uncoupling protein 2 (by 77.5%; P < 0.05) and adiponectin (by 76.3%; P > 0.05) were up-regulated due to pteryxin. CONCLUSION: Our study demonstrated that pteryxin in PJT plays the key role in regulating the lipid metabolism-related gene network and improving energy production in vitro. Thus, the results suggest pteryxin as a new natural compound to be used as an antiobesity drug in the pharmaceutical industry.

Partially purified Peucedanum japonicum Thunb extracts exert anti-obesity effects in vitro.

OBJECTIVE: Crude ethanolic extract of Peucedanum japonicum Thunb (PJT) has been identified as an antiobesity and antidiabetic candidate. The aim of this study was to assess the mechanisms related to the antiobesity activity of partially purified PJT ethanol extract in vitro. METHODS: PJT ethanol extract (EE) was partitioned into hexane phase (HP) and residual water phase. The effect of PJT extracts on triacylglycerol (TG) content, lipid metabolism-related gene expression, and energy expenditure was assessed in vitro in 3T3-L1, HepG2, and C2C12 cells. Furthermore, the active components in PJT extracts were partially profiled by high-performance liquid chromatography (HPLC) analysis. RESULTS: The HP significantly down-regulated lipogenic gene expressions in hepatocytes, inhibited TG accumulation, and decreased the size of 3T3-L1 adipocytes. Moreover, the inhibition of lipid accumulation was at maximum during the adipocyte maturation stage. Furthermore, we found an increase in fat hydrolysis by HP in 3T3-L1. In C2C12 myotubes, the HP tended to enhance energy expenditure. HPLC analysis demonstrated that hydrophobic compounds available in the HP were responsible for antiobesity, which corresponded to the latter peaks on the HPLC chromatogram of EE. CONCLUSION: Our study demonstrated that the HP plays a crucial role in regulating lipid metabolism-related gene expressions and energy expenditure in vitro. The results thus provide insight on the activity of HP involved in suppressing obesity and its chemical entities.

Reoxygenation from chronic hypoxia promotes metastatic processes in pancreatic cancer through the Hedgehog signaling.

Pancreatic ductal adenocarcinoma (PDAC) is among the most deadly types of malignancies because of its high ability to metastasize. PDAC is thought to be under hypoxic condition. Therefore, to investigate the mechanism of metastatic processes, chronic-hypoxia-resistant PDAC cells were newly generated under hypoxic condition for 3-6 months and reoxygenation experiments were performed using these chronic-hypoxia-resistant PDAC cells in in vivo-mimicking conditions. Proliferation, invasiveness and tumorigenicity in PDAC cells were significantly increased by reoxygenation. A Hedgehog (Hh) signaling component, Gli1, was significantly increased by reoxygenation. Gli1 knockdown inhibited reoxygenation-induced increases in proliferation and tumorigenicity and decreased invasiveness through suppression of matrix metalloproteinase (MMP) 2 and MMP9. Moreover, inhibition of Sonic Hh and Smoothened abrogated reoxygenation induced increases in proliferation and invasiveness. These results suggest that metastatic processes in PDAC are induced through activation of the Hh signaling pathway. Therefore, the Hh signaling pathway may be a therapeutic target for refractory PDAC in metastatic processes induced by reoxygenation.

Mechanism of arctigenin-mediated specific cytotoxicity against human lung adenocarcinoma cell lines.

The lignan arctigenin (ARG) from the herb Arctium lappa L. possesses anti-cancer activity, however the mechanism of action of ARG has been found to vary among tissues and types of cancer cells. The current study aims to gain insight into the ARG mediated mechanism of action involved in inhibiting proliferation and inducing apoptosis in lung adenocarcinoma cells. This study also delineates the cancer cell specificity of ARG by comparison with its effects on various normal cell lines. ARG selectively arrested the proliferation of cancer cells at the G0/G1 phase through the down-regulation of NPAT protein expression. This down-regulation occurred via the suppression of either cyclin E/CDK2 or cyclin H/CDK7, while apoptosis was induced through the modulation of the Akt-1-related signaling pathway. Furthermore, a GSH synthase inhibitor specifically enhanced the cytotoxicity of ARG against cancer cells, suggesting that the intracellular GSH content was another factor influencing the susceptibility of cancer cells to ARG. These findings suggest that specific cytotoxicity of ARG against lung cancer cells was explained by its selective modulation of the expression of NPAT, which is involved in histone biosynthesis. The cytotoxicity of ARG appeared to be dependent on the intracellular GSH level.

Triangulating stapling technique for esophagogastrostomy after minimally invasive esophagectomy.

BACKGROUND: The triangulating stapling technique is one of the reconstruction methods used that provides favorable surgical outcomes in several areas of the digestive tract. However, the results in the cervical esophagogastric anastomosis are not well documented. METHODS: Using a prospectively maintained comprehensive database, we reviewed the surgical results of 160 consecutive patients who underwent minimally invasive esophagectomy followed by cervical triangulating stapling esophagogastrostomy during 2 periods from May 2002 to May 2012 so as to determine the efficacy of the triangulating stapling technique using 2 different types of stapling devices. RESULTS: The rates of anastomotic leakage and stricture in this series were low (1% and 15%, respectively). The rate of anastomotic stricture was significantly reduced when a linear stapler with a cutting knife was used (9%). A logistic regression analysis showed a reduction of anastomotic stricture to be significantly associated with the use of only a linear stapler with a cutting knife. CONCLUSION: Cervical esophagogastric anastomosis by the triangulating stapling technique is safe and feasible. We consider a linear stapling device equipped with a cutting knife to be more suitable for performing the triangulating stapling technique.

Hedgehog Gli3 activator signal augments tumorigenicity of colorectal cancer via upregulation of adherence-related genes.

Hedgehog signal is re-activated in several cancers. In this study, we examined the role of Gli3 on malignant phenotype of tumorigenicity for colorectal cancer and its relationship with p53, WNT and ERK/AKT signals. Gli3 expression was detected in HT29 and SW480 (p53-mutant) cells, but not in DLD-1 (p53-mutant) or HCT116 (p53-wild type) cells by reverse transcription-polymerase chain reaction and immunocytochemistry. Full-length Gli3 transfection increased anchor-independent growth for all cells regardless of p53 status, with upregulation of adhesion-related genes. Exogenous Sonic-Hedgehog increased activator-type of Gli3 and colony formation in Gli3-positive HT29 and SW480 cells. After implantation of Gli3-FL or mock-transfectant DLD-1 cells into SCID mice, tumor formation was highly observed in only Gli3-FL-transfectant group. In clinical specimens, Gli3 expression was detected in subsets of colorectal cancer and related with poorly-differentiated histological type, while Sonic-Hedgehog was present with high incidence. In conclusion, activator Gli3 signal augments tumorigenicity of colorectal cancer irrespective of p53 status.

Hedgehog inhibitor decreases chemosensitivity to 5-fluorouracil and gemcitabine under hypoxic conditions in pancreatic cancer.

Pancreatic cancer is one of the deadliest types of cancer. Previously, we showed that hypoxia increases invasiveness through upregulation of Smoothened (Smo) transcription in pancreatic ductal adenocarcinoma (PDAC) cells. Here, we first evaluated whether hypoxia-induced increase in Smo contributes to the proliferation of PDAC cells. We showed that Smo, but not Gli1, inhibition decreases proliferation significantly under hypoxic conditions. To further investigate the effects of Smo on PDAC growth, cell cycle analysis was carried out. Inhibition of Smo under hypoxia led to G(0) /G(1) arrest and decreased S phase. As 5-fluorouracil (5-FU) and gemcitabine, which are first-line drugs for pancreatic cancer, are sensitive to S phase, we then evaluated whether cyclopamine-induced decreased S phase under hypoxia affected the chemosensitivity of 5-FU and gemcitabine in PDAC cells. Cyclopamine treatment under hypoxia significantly decreased chemosensitivity to 5-FU and gemcitabine under hypoxia in both in vitro and in vivo models. In contrast, cis-diamminedichloroplatinum, which is cell cycle-independent, showed significant synergistic effects. These results suggest that hypoxia-induced increase of Smo directly contributes to the proliferation of PDAC cells through a hedgehog/Gli1-independent pathway, and that decreased S phase due to the use of Smo inhibitor under hypoxia leads to chemoresistance in S phase-sensitive anticancer drugs. Our results could be very important clinically because a clinical trial using Smo inhibitors and chemotherapy drugs will begin in the near future.

Tumor specific cytotoxicity of arctigenin isolated from herbal plant Arctium lappa L.

The effectiveness of cancer chemotherapy is often limited by the toxicity to other tissues in the body. Therefore, the identification of non-toxic chemotherapeutics from herbal medicines remains to be an attractive goal to advance cancer treatments. This study evaluated the cytotoxicity profiles of 364 herbal plant extracts, using various cancer and normal cell lines. The screening found occurrence of A549 (human lung adenocarcinoma) specific cytotoxicity in nine species of herbal plants, especially in the extract of Arctium lappa L. Moreover, purification of the selective cytotoxicity in the extract of Arctium lappa L. resulted in the identification of arctigenin as tumor specific agent that showed cytotoxicity to lung cancer (A549), liver cancer (HepG2) and stomach cancer (KATO III) cells, while no cytotoxicity to several normal cell lines. Arctigenin specifically inhibited the proliferation of cancer cells, which might consequently lead to the induction of apoptosis. In conclusion, this study found that arctigenin was one of cancer specific phytochemicals, and in part responsible for the tumor selective cytotoxicity of the herbal medicine.

Effect of Peucedanum japonicum Thunb extract on high-fat diet-induced obesity and gene expression in mice.

Supplementation of the diet with Peucedanum japonicum Thunb (PJT) powder inhibits high-fat diet-induced obesity in mice. Either the fiber component or other bioactive components in the PJT powder may inhibit obesity. This study, therefore, was an attempt to identify the components, fiber or other phytochemicals of PJT that were responsible for the anti-obesity activity, and also studied the modulation of obesity-related gene expression in C57BL/6 mice. Animals were fed a modified-AIN76 diet supplemented with PJT powder or extracts of PJT in water, 50 % ethanol, or ethanol. Body weight gain, tissue weight, serum biochemical parameters, liver lipid concentrations, and gene expression in tissues were compared between the control and treatment groups. Of the extracts, the ethanol extract of PJT decreased fat accumulation and adipocyte size, reduced serum and liver triglyceride concentrations, and inhibited obesity. This finding clearly demonstrates the presence of anti-obesity phytochemicals in PJT. Ethanol extract of PJT inhibited lipase activity in vitro. Modulation of gene expression by PJT ethanol extract was largely similar to that by PJT powder in the hepatic and adipose tissues: RORC and PBEF1 were upregulated and DUSP1, INSIG2, and SERPINA12 were downregulated in the liver; FXRα and PPARγ were upregulated and PEG1/MEST, the size-marker of adipocytes, was downregulated in the adipose tissue. Furthermore, PJT ethanol extract increased the expression of the UCP3 gene in muscle. These results suggest that the anti-obesity phytochemicals in PJT lower lipid levels by inhibiting fat absorption and by modulating obesity-related gene expression in the liver, adipose tissue, and muscle.