Icariin Ameliorates D-galactose-induced Cell Injury in Neuron-like PC12 Cells by Inhibiting MPTP Opening.

OBJECTIVE: Icariin (ICA) has a good neuroprotective effect and can upregulate neuronal basal autophagy in naturally aging rats. Mitochondrial dysfunction is associated with brain aging-related neurodegenerative diseases. Abnormal opening of the mitochondrial permeability transition pore (mPTP) is a crucial factor in mitochondrial dysfunction and is associated with excessive autophagy. This study aimed to explore that ICA protects against neuronal injury by blocking the mPTP opening and down-regulating autophagy levels in a D-galactose (D-gal)-induced cell injury model. METHODS: A cell model of neuronal injury was established in rat pheochromocytoma cells (PC12 cells) treated with 200 mmol/L D-gal for 48 h. In this cell model, PC12 cells were pre-treated with different concentrations of ICA for 24 h. MTT was used to detect cell viability. Senescence associated ß-galactosidase (SA-ß-Gal) staining was used to observe cell senescence. Western blot analysis was performed to detect the expression levels of a senescence-related protein (p21), autophagy markers (LC3B, p62, Atg7, Atg5 and Beclin 1), mitochondrial fission and fusion-related proteins (Drp1, Mfn2 and Opa1), and mitophagy markers (Pink1 and Parkin). The changes of autophagic flow were detected by using mRFP-GFP-LC3 adenovirus. The intracellular ultrastructure was observed by transmission electron microscopy. Immunofluorescence was used to detect mPTP, mitochondrial membrane potential (MMP), mitochondrial reactive oxygen species (mtROS) and ROS levels. ROS and apoptosis levels were detected by flow cytometry. RESULTS: D-gal treatment significantly decreased the viability of PC12 cells, and markedly increased the SA-ß-Gal positive cells as compared to the control group. With the D-gal stimulation, the expression of p21 was significantly up-regulated. Furthermore, D-gal stimulation resulted in an elevated LC3B II/I ratio and decreased p62 expression. Meanwhile, autophagosomes and autolysosomes were significantly increased, indicating abnormal activation of autophagy levels. In addition, in this D-gal-induced model of cell injury, the mPTP was abnormally open, the ROS generation was continuously increased, the MMP was gradually decreased, and the apoptosis was increased. ICA effectively improved mitochondrial dysfunction to protect against D-gal-induced cell injury and apoptosis. It strongly inhibited excessive autophagy by blocking the opening of the mPTP. Cotreatment with ICA and an mPTP inhibitor (cyclosporin A) did not ameliorate mitochondrial dysfunction. However, the protective effects were attenuated by cotreatment with ICA and an mPTP activator (lonidamine). CONCLUSION: ICA inhibits the activation of excessive autophagy and thus improves mitochondrial dysfunction by blocking the mPTP opening.

Saponins from Panax japonicus improve neuronal mitochondrial injury of aging rats.

CONTEXT: Panax japonicus is the dried rhizome of Panax japonicus C.A. Mey. (Araliaceae). Saponins from Panax japonicus (SPJ) exhibit anti-oxidative and anti-aging effects. OBJECTIVE: We evaluated the neuroprotective effects of SPJ on aging rats. MATERIALS AND METHODS: Sprague-Dawley rats (18-months-old) were randomly divided into aging and SPJ groups (n = 8). Five-month-old rats were taken as the adult control (n = 8). The rats were fed a normal chow diet or the SPJ-containing diet (10 or 30 mg/kg) for 4 months. An in vitro model was established by d-galactose (d-Gal) in the SH-SY5Y cell line and pretreated with SPJ (25 and 50 µg/mL). The neuroprotection of SPJ was evaluated via Nissl staining, flow cytometry, transmission electron microscopy and Western blotting in vivo and in vitro. RESULTS: SPJ improved the neuronal degeneration and mitochondrial morphology that are associated with aging. Meanwhile, SPJ up-regulated the protein levels of mitofusin 2 (Mfn2) and optic atrophy 1 (Opa1) and down-regulated the protein level of dynamin-like protein 1 (Drp1) in the hippocampus of aging rats (p < 0.05 or p < 0.01 vs. 22 M). The in vitro studies also demonstrated that SPJ attenuated d-Gal-induced cell senescence concomitant with the improvement in mitochondrial function; SPJ, also up-regulated the Mfn2 and Opa1 protein levels, whereas the Drp1 protein level (p < 0.05 or p < 0.01 vs. d-Gal group) was down-regulated. DISCUSSION AND CONCLUSIONS: Further research on the elderly population will contribute to the development and utilization of SPJ for the treatment of neurodegenerative disorders.

Comprehensive analysis of pedicle screw implantation in the C7 vertebra using computed tomography-based three-dimensional models.

BACKGROUND: From a biomechanical point of view, pedicle screws (PS) are better than other kinds of screws for implantation in the seventh cervical vertebra (C7). However, the application of PS is limited because of the high risk of severe complications. It is essential to define the optimal entry point and trajectory. The aim of this study was to comprehensively analyze the starting point and trajectory for C7 PS insertion using three dimensional (3D) models. METHODS: Overall, 60 subjects aged 18 to 67 years old were included. All CT images were used to construct 3D computer models of the C7 vertebrae. A new coordinate system was established for the next evaluation. The pedicle axis was calculated with respect to the entire pedicle; then, the ideal entry point, screw diameter and length, sagittal angle and lateral angle were assessed. RESULTS: All the ideal entry points were located at the medial superior to lateral notch (LN), and the mean distance between the entry point and LN was 5.86 ± 1.67 mm in the horizontal direction and 3.47 ± 1.57 mm in the vertical direction. The mean distance between the entry point and the middle point of the inferior edge of the C6 articular process (MP) was 0.74 ± 1.83 mm in the horizontal direction. The mean sagittal angle of the pedicle axis was 90.42°, and the mean pedicle transverse angle was 30.70°. The average diameter and length of the PS were 6.51 ± 0.76 mm and 31.58 ± 4.40 mm, respectively. CONCLUSIONS: This study provided a novel method to calculate the ideal starting point and trajectory for C7 PS insertion. These measurements may be helpful for preoperative planning. It is recommended that 3D CT imaging is used preoperatively to carefully evaluate the anatomy of each individual.

A Hypoxia-Induced SCFFBXL1 E3 Ligase Ubiquitinates and Degrades the MEN1 Tumor Suppressor to Promote Colorectal Cancer Tumorigenesis.

PURPOSE: Emerging evidence has shown that SKP1-cullin-1-F-box-protein (SCF) E3 ligases contribute to the pathogenesis of different cancers by mediating the ubiquitination and degradation of tumor suppressors. However, the functions of SCF E3 ligases in the pathogenesis of colorectal cancer (CRC) remain obscure. MATERIALS AND METHODS: The cancerous and adjacent noncancerous tissues from CRC patients were collected, and protein levels were analyzed. Lentiviral short hairpin RNA (shRNA) and plasmid transfection were used to knock down and overexpress gene expression in CRC cell lines. Immunoprecipitation (IP), mass spectrometry, and co-IP analyses were used to determine protein interactions and the assembly of the SCF complex. Cell proliferation, migration, and tumor xenograft assays were performed to examine the effects of SCF members on CRC cell growth in vitro and in vivo. RESULTS: Hypoxia activated the docking of hypoxia-inducible factor 1α (HIF1α) onto the CUL1 promoter and induced CUL1 expression in CRC cells. CUL1 coupled with RBX1, SKP1, and FBXL1 to assemble the SCFFBXL1 complex in CRC biopsies and cells. The SCFFBXL1 E3 ligase specifically ubiquitinated and degraded the MEN1 tumor suppressor. Knockdown of HIF1α or SCFFBXL1 members, or blockage of SCFFBXL1 by two inhibitors (DT204 and SZLP1-41) caused the accumulation of MEN1 protein and led to a significant decrease in cell proliferation and migration in vitro and tumor growth in vivo. CONCLUSION: The SCFFBXL1 E3 ligase is required for the ubiquitination of MEN1, and disruption of this complex may represent a new therapeutic strategy for the treatment of CRC.

Machine learning-based quantitative analysis of barium enema and clinical features for early diagnosis of short-segment Hirschsprung disease in neonate.

OBJECTIVE: To develop a mathematical model based on a combination of clinical and radiologic features (barium enema) for early diagnosis of short-segment Hirschsprung disease (SHSCR) in neonate. METHODS: The analysis included 54 neonates with biopsy-confirmed SHSCR (the cases) and 59 neonates undergoing barium enema for abdominal symptoms but no Hirschsprung disease (the control). Colon shape features extracted from barium enema images and clinical features were used to develop diagnostic models using support vector machine (SVM) and L2-regularized logistic regression (LR). The training cohort included 32 cases and 37 controls; testing cohort consisted 22 cases and 22 controls. Results were compared to interpretation by 2 radiologists. RESULTS: In the analysis by radiologists, 87 out of 113 cases were correctly classified. Six SHSCR cases were mis-classified into the non-HSCR group. In the remaining 20 cases, radiologists were unable to make a decision. Both the SVM and LR classifiers contained five clinical features and four shape features. The performance of the two classifiers was similar. The best model had 86.36% accuracy, 81.82% sensitivity, and 90.91% specificity. The AUC was 0.9132 for the best-performing SVM classifier and 0.9318 for the best-performing LR classifier. CONCLUSION: A combination of clinical features and colon shape features extracted from barium enemas can be used to improve early diagnosis of SHSCR in neonate.

Spinal cord injury in an adult patient with thoracic butterfly vertebra: a case report and review of the literature.

BACKGROUND: Butterfly vertebrae are a rare congenital vertebral anomaly. An overlap of this spinal anomaly with other diseases has been reported. However, to the authors' knowledge, the coexistence of butterfly vertebrae and spinal cord injury has not been reported in the literature. CASE PRESENTATION: A 42-year-old male was admitted to our emergency department after a motor vehicle accident. His complaint was back pain, and he was unable to move both lower limbs. Upon physical examination, the patient was not ambulatory. Sensory examination revealed the absence of sensation below the T12 level. The strength of the bilateral lower limbs was grade 0. The patient received a radiographic evaluation. The initial diagnosis was T11 fracture with complete paraplegia of the lower limbs. Magnetic resonance imaging (MRI) was then performed. Sagittal MRI demonstrated an isointense lesion on T1-weighted imaging and a high-signal spindle-like lesion on T2-weighted imaging of the spinal cord adjacent to the T11 vertebra. The fat-suppressed sequence also revealed hyperintensities of the cord. There was no evidence of acute injury of the T11 vertebral body except for cuneiform anterior wedging. The patient was ultimately diagnosed with complete paraplegia with a T11 butterfly vertebra. He underwent urgent posterior decompressive and fixation surgery from T10 to T12. His postoperative recovery was uneventful. CONCLUSIONS: The coexistence of a butterfly vertebra with spinal cord injury was reported for the first time. Although butterfly vertebrae may be incidentally detected, it is important to be familiar with their radiographic features to distinguish them from fractures.

The CtBP1-p300-FOXO3a transcriptional complex represses the expression of the apoptotic regulators Bax and Bim in human osteosarcoma cells.

C-terminal binding protein 1 (CtBP1), a well-known transcriptional corepressor, functions as an oncogene in multiple cancer types, including osteosarcoma, by modulating the transcription of many tumor suppressors, such as cadherin 1 (CDH1), phosphatase and tensin homolog (PTEN), Bcl2-associated X (Bax), Bcl-2-interacting mediator (Bim), and cyclin-dependent kinase inhibitor 1A (CDKN1A). However, it is still unclear how CtBP1 regulates the expression of these downstream targets. Here, we identified that CtBP1 is overexpressed in osteosarcoma cells and found that CtBP1 directly interacts with the transcription factor forkhead box O3 (FOXO3a) and the histone acetyltransferase p300 in vivo and in vitro. Through microarray analysis, we found that CtBP1 negatively regulates FOXO3a levels. In contrast to the CtBP1 level, the FOXO3a expression level was found to be significantly reduced in osteosarcoma cells. Knockdown of CtBP1 or overexpression of FOXO3a in U2OS cells resulted in different gene expression patterns, and the former caused upregulation of CtBP1 downstream target genes such as CDH1, PTEN, Bax, Bim, and CDKN1A, whereas the latter caused upregulation of Bax and Bim, but not CDH1, PTEN, and CDKN1A. Further analysis indicated that the CtBP1-p300-FOXO3a transcriptional complex specifically binds to the promoters of Bax and Bim. Inhibition of CtBP1 by the constitutive expression of Pep1-E1AWT peptide in U2OS and OSA cells reversed oncogenic phenotypes, including colony formation, cellular proliferation, and migration, and limited tumor growth in vivo. Together our results demonstrated that the CtBP1-p300-FOXO3a transcriptional complex represses the expression of the apoptotic regulators Bax and Bim in human osteosarcoma cells and that targeting CtBP1-mediated transcriptional events might be a potential therapeutic strategy for the osteosarcoma treatment.

Saponins from Panax japonicus attenuate age-related neuroinflammation via regulation of the mitogen-activated protein kinase and nuclear factor kappa B signaling pathways.

Neuroinflammation is recognized as an important pathogenic factor for aging and related cognitive disorders. Mitogen-activated protein kinase and nuclear factor kappa B signaling pathways may mediate neuroinflammation. Saponins from Panax japonicus are the most abundant and bioactive members in rhizomes of Panax japonicus, and show anti-inflammatory activity. However, it is not known whether saponin from Panax japonicus has an anti-inflammatory effect in the aging brain, and likewise its underlying mechanisms. Sprague-Dawley rats were divided into control groups (3-, 9-, 15-, and 24-month-old groups) and saponins from Panax japonicus-treated groups. Saponins from Panax japonicus-treated groups were orally administrated saponins from Panax japonicus at three doses of 10, 30, and 60 mg/kg once daily for 6 months until the rats were 24 months old. Immunohistochemical staining and western blot assay results demonstrated that many microglia were activated in 24-month-old rats compared with 3- and 9-month-old rats. Expression of interleukin-1ß, tumor necrosis factor-α, cyclooxygenase-2, and inducible nitric oxide synthase increased. Each dose of saponins from Panax japonicus visibly suppressed microglial activation in the aging rat brain, and inhibited expression levels of the above factors. Each dose of saponins from Panax japonicus markedly diminished levels of nuclear factor kappa B, IκBα, extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38. These results confirm that saponins from Panax japonicus can mitigate neuroinflammation in the aging rat brain by inhibition of the mitogen-activated protein kinase and nuclear factor kappa B signaling pathways.

Nilotinib reverses ABCB1/P-glycoprotein-mediated multidrug resistance but increases cardiotoxicity of doxorubicin in a MDR xenograft model.

The BCR-Abl tyrosine kinase inhibitor (TKI), nilotinib, was developed to surmount resistance or intolerance to imatinib in patients with Philadelphia-positive chronic myelogenous leukemia. Recent studies have shown that nilotinib induces potent sensitization to anticancer agents by blocking the functions of ABCB1/P-glycoprotein (P-gp) in multidrug resistance (MDR). However, changes in P-gp expression or function affect the cardiac disposition and prolong the presence of both doxorubicin (DOX) and doxorubicinol (DOXol) in cardiac tissue, thus, enhancing the risk of cardiotoxicity. In this study, we used a MDR xenograft model to evaluate the antitumor activity, tissue distribution and cardiotoxicity of DOX when co-administered with nilotinib. This information will provide more insight into the pharmacological role of nilotinib in MDR reversal and the risk of DOX cardiotoxicity. Our results showed that nilotinib significantly enhanced DOX cytotoxicity and increased intracellular rhodamine 123 accumulation in MG63/DOX cells in vitro and strongly enhanced DOX inhibition of growth of P-gp-overexpressing MG63/DOX cell xenografts in nude mice. Additionally, nilotinib significantly increased DOX and DOXol accumulation in serum, heart, liver and tumor tissues. Importantly, nilotinib induced a disproportionate increase in DOXol in cardiac tissue. In the co-administration group, CBR1 and AKR1A1 protein levels were significantly increased in cardiac tissue, with more severe necrosis and vacuole formation. These results indicate that nilotinib reverses P-gp- mediated MDR by blocking the efflux function and potentiates DOX-induced cardiotoxicity. These findings represent a guide for the design of future clinical trials and studies of pharmacokinetic interactions and may be useful in guiding the use of nilotinib in combination therapy of cancer in clinical practice.

Chikusetsusaponin V attenuates lipopolysaccharide-induced liver injury in mice.

Chikusetsusaponin V (CsV), a saponin from Panax japonicus, has been reported to inhibit inflammatory responses in lipopolysaccharide (LPS)-induced macrophage cells. However, whether CsV could alleviate LPS-induced liver injury in vivo and the potential mechanisms involved remain unclear. In the present study, we investigated the anti-inflammatory effects of CsV on LPS-induced acute liver injury in mice and further explored the potential mechanisms involved. Our results showed that CsV significantly attenuated elevation of alanine transaminase (ALT) and aspartate aminotransferase (AST) levels and improved liver histopathological changes in LPS-induced mice. In addition, CsV decreased serum tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) levels and inhibited mRNA expressions of inducible nitric oxide synthase (iNOS), TNF-α and IL-1ß in LPS challenged mice. Furthermore, CsV inhibited nuclear factor kappa B (NF-κB) activation by downregulating phosphorylated NF-κB, IκB-α, ERK, c-Jun N-terminal kinase (JNK) and p38 levels in the liver tissue, which ultimately decreased nucleus NF-κB protein level. In conclusion, our data suggested that CsV could be a promising drug for preventing LPS challenged liver injury since it attenuated LPS-induced inflammatory responses, partly via inhibiting NF-κB and MAPK signaling pathways.

Chikusetsu saponin V attenuates MPP+-induced neurotoxicity in SH-SY5Y cells via regulation of Sirt1/Mn-SOD and GRP78/caspase-12 pathways.

Studies have shown that saponins from Panax japonicus (SPJ) possess neuroprotective effects. However, whether Chikusetsu saponin V (CsV), the most abundant member of SPJ, can exert neuroprotective effects against 1-methyl-4-phenylpyridinium ion (MPP+)-induced cytotoxicity is not known. In this study, we aimed to investigate the neuroprotective effects of CsV on MPP+-induced cytotoxicity in human neuroblastoma SH-SY5Y cells and explore its possible mechanisms. Our results show that CsV attenuates MPP+-induced cytotoxicity, inhibits ROS accumulation, and increases mitochondrial membrane potential dose-dependently. We also found that levels of Sirt1 protein and Mn-SOD mRNA significantly decreased in MPP+-treated group but were restored with CsV treatment in a dose-dependent manner. Furthermore, GRP78 protein and Caspase-12 mRNA levels were elevated by MPP+ exposure but reversed by CsV treatment. CsV inhibited the MPP+-induced downregulation of Bcl-2 and up-regulation of Bax in a dose-dependent manner and, thus, increased the ratio of Bcl-2/Bax. Overall, these results suggest that Sirt1/Mn-SOD and GRP78/Caspase-12 pathways might be involved in the CsV-mediated neuroprotective effects.

In vitro inhibitory effects of scutellarin on six human/rat cytochrome P450 enzymes and P-glycoprotein.

Inhibition of cytochrome P450 (CYP) and P-glycoprotein (P-gp) are regarded as the most frequent and clinically important pharmacokinetic causes among the various possible factors for drug-drug interactions. Scutellarin is a flavonoid which is widely used for the treatment of cardiovascular diseases. In this study, the in vitro inhibitory effects of scutellarin on six major human CYPs (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) and six rat CYPs (CYP1A2, CYP2C7, CYP2C11, CYP2C79, CYP2D4, and CYP3A2) activities were examined by using liquid chromatography-tandem mass spectrometry. Meanwhile, the inhibitory effects of scutellarin on P-gp activity were examined on a human metastatic malignant melanoma cell line WM-266-4 by calcein-AM fluorometry screening assay. Results demonstrated that scutellarin showed negligible inhibitory effects on the six major CYP isoenzymes in human/rat liver microsomes with almost all of the IC50 values exceeding 100 µM, whereas it showed values of 63.8 µM for CYP2C19 in human liver microsomes, and 63.1 and 85.6 µM for CYP2C7 and CYP2C79 in rat liver microsomes, respectively. Scutellarin also showed weak inhibitory effect on P-gp. In conclusion, this study demonstrates that scutellarin is unlikely to cause any clinically significant herb-drug interactions in humans when co-administered with substrates of the six CYPs (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) and P-gp.

Evaluation of the pharmacokinetics and cardiotoxicity of doxorubicin in rat receiving nilotinib.

Doxorubicin (DOX) is a potent chemotherapy drug with a narrow therapeutic window. Nilotinib, a small-molecule Bcr-Abl tyrosine kinase inhibitor, was reported to reverse multidrug resistance (MDR) mediated by P-glycoprotein (P-gp) transmembrane transporters. The present study aimed to investigate nilotinib's affection on the steady-state pharmacokinetics, disposition and cardiotoxicity of DOX. A total of 24 male Sprague-Dawley rats were randomized into four groups (6 in each) and received the following regimens: saline, intravenous DOX (5mg/kg) alone, and DOX co-administrated with either 20 or 40mg/kg nilotinib. Blood was withdrawn at 12 time points till 72h after DOX injection and the concentrations of DOX and its metabolite doxorubicinol (DOXol) in serum and cardiac tissue were assayed by LC-MS-MS method. To determine the cardiotoxicity, the following parameters were investigated: creatine kinase, lactate dehydrogenase, malondialdehyde, and superoxide dismutase. Histopathological examination of heart section was carried out to evaluate the extent of cardiotoxicity after treatments. The results showed that pretreatment of 40mg/kg nilotinib increased the AUC0-t and Cmax of DOX and DOXol. However, their accumulation in cardiac tissue was significantly decreased when compared with the group that received DOX alone. In addition, biochemical and histopathological results showed that 40mg/kg nilotinib reduced the cardiotoxicity induced by DOX administration. In conclusion, co-administration of nilotinib increased serum exposure, but significantly decreased the accumulation of DOX in cardiac tissue. Consistent with in vitro profile, oral dose of 40mg/kg nilotinib significantly decreased the cardiotoxicity of DOX in rat by enhancing P-gp activity in the heart.

[Expression levels of Slc7a11 in the skin of Kazakh sheep with different coat colors].

Slc7a11 belongs to solute transporter gene family, encoding cystine/glutamate transporter xCT. It regulates switching between eumelanin and pheomelanin synthesis. In the present study, Real-time PCR was used to detect the mRNA expression levels of Slc7a11 in the skin of Kazakh lambs with different coat colors (black, brown and white), and then the prokaryotic expression plasmid PET-32a-sxCT was constructed to induce the expression of fusion protein. The target pro-tein was purified by Ni-NTA affinity chromatographic separation, and then was used to immunize rabbit in order to produce rabbit anti-sxCT polyclonal antibody. Finally, the expression levels of sxCT were detected in the skin of Kazakh lambs with different hair colors by Western blotting analysis. Results showed that the mRNA expression levels of Slc7a11 differed significantly in the skin of Kazakh lambs with different coat colors, with the highest level in brown coat color, followed by the black, and then the white. The sxCT protein was also detected in the skin of different coat colors by polyclonal antibody, with the highest level in brown coat color, followed by the black, and then the white. It is, therefore, concluded that slc7a11 gene might be associated with the phenotype of coat color in Kazakh sheep.

Osteopontin is overexpressed in colorectal carcinoma and is correlated with P53 by immunohistochemistry.

Osteopontin (OPN), a secreted phosphorylated glycoprotein, has been found to be involved in carcinogenesis, progression and metastasis of several types of cancers. The aim of the present study was to investigate the immunohistochemical expression of OPN in colorectal carcinoma (CRC) and its relationship with clinicopathological parameters and P53. Expression of OPN, Ki-67 and TP53 was detected in 77 cases of CRC by immunohistochemistry and the correlation of the expression of OPN with clinicopathological features, Ki-67 and P53 staining was investigated. Thirty-eight cases (49.4%) of CRC demonstrated OPN overexpression. Overexpression of OPN was associated with lymph node metastasis (P=0.025) and Dukes' stages (P=0.031), but not with gender, histological differentiation, depth of tumor invasion, TNM stages or Ki-67 index. The correlation between expression of OPN and TP53 was statistically significant (P=0.030). In conclusion, OPN is overexpressed in CRC, and plays a role in tumor progression and metastasis, which is possibly regulated by P53.

Inhibitory effects of limonin on six human cytochrome P450 enzymes and P-glycoprotein in vitro.

Among the various possible causes for drug interactions, pharmacokinetic factors such as inhibition of drug-metabolizing enzymes and transporters, especially cytochrome P450 (CYP) isoenzymes and P-glycoprotein (P-gp), are regarded as the most frequent and clinically important. Limonin is a widely used dietary supplement and one of the most prevalent citrus limonoids, which are known to have inhibitory effects on CYPs and P-gp. In this study, the in vitro inhibitory effects of limonin on the major human CYP isoenzymes (CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) activities in human liver microsomes were examined using liquid chromatography-tandem mass spectrometry. The inhibitory effects of limonin on P-gp activity in a human metastatic malignant melanoma cell line WM-266-4 were examined using a calcein-AM fluorometry screening assay. It demonstrates that limonin has negligible inhibitory effects on human CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and P-gp. However, potent inhibition of CYP3A4 by limonin is observed with IC50 values of 6.20 µM (CYP3A4/testosterone) and 19.10 µM (CYP3A4/midazolam). This finding has important implications with regard to food-drug interactions between limonin and several narrow therapeutic index drugs that are metabolized by CYP3A4.

Clinical features and molecular alterations of traditional serrated adenoma in sporadic colorectal carcinogenesis.

OBJECTIVE: To compare clinical features and molecular alterations between traditional serrated adenomas (TSA) & serrated carcinomas (SCa) and traditional adenomas (TA) & carcinomas (Ca) of the colorectum and to verify a traditional serrated pathway of sporadic colorectal carcinogenesis. METHODS: One thousand two hundred slides of colorectal polyps obtained from 1160 patients were collected and reviewed to define TSA and clinical and pathological features were analyzed and compared with TA. DNA was extracted from specimens of TSA, TA, SCa and Ca, v-raf murine sarcoma viral oncogene homolog B (BRAF) V600E mutation and microsatellite instability (MSI) (assay for BAT25 and BAT26) were analyzed. RESULTS: Overall 29 TSA were confirmed (2.5%), and there was an age difference between patients with TSA and TA (56.0 vs 62.7, P<0.05). Compared with TA, TSA was located more often in the rectosigmoid colon (TSA 62.1% vs TA 35.2%, P<0.05), but occurred less in the descending colon (TSA 0% vs TA 25.35%, P=0.0068). No difference was found in terms of gender and the size or pedicles of polyps (P>0.05). The BRAF V600E mutation was detected in 36.3% of SCa and 26.7% of TSA patients, but it was not detected in TA and Ca patients; MSI-H was noticed in 23% of SCa, 33.3% of TSA, 5.3% of Ca and 0% of TA patients, respectively (P<0.05). CONCLUSION: There might be a traditional serrated pathway of sporadic colorectal carcinogenesis that is different from the conventional adenoma to carcinoma carcinogenesis pathway in the colorectum.

[A study on microsatellite instability status for colorectal serrated lesions].

OBJECTIVE: To verify the traditional serrated pathway by comparing microsatellite instability (MSI) status among traditional serrated adenoma, traditional adenoma, serrated colorectal cancer and non-serrated colorectal cancer. METHODS: Seventy-five paraffin-embedded tissue samples, including 15 with serrated adenocarcinoma (Sca), 20 with non-serrated adenocarcinoma (N-Sca), 20 with traditional serrated adenoma (TSA) and 20 with villous adenoma (AD) were collected from the pathology department of our hospital. Genomic DNA was extracted from these samples and then amplified with fluorescently-labeled primer specific for BAT25 and BAT26. The MSI status was detected with DNA automatic sequencer. RESULTS: Six of 18 samples with TSA harbored MSI-H and twelve MSI-L/MSS; 18 samples with conventional adenoma were exclusively of MSS; 3 of 13 samples of serrated carcinoma harbored MSI-H and ten MSI-L/MSS; 18 of 19 N-Sca samples harbored MSI-L/MSS and only one MSI-H. With Chi-square test, the MSI frequency in AD group and N-Sca group was significantly lower than that in TSA group and Sca group (P<0.05); but with no statistical difference between the TSA group and Sca groups (P>0.05). CONCLUSION: MSI-H frequency in AD group and N-Sca group was obviously lower than that of TSA group and Sca group. It is concluded that there might be a new traditional serrated neoplasia pathway which is different from the conventional adenoma-carcinoma carcinogenesis pathway, but we still need prospective follow-up studies to verify its existence.

[Clinicopathological and immunohistochemical features of colorectal sessile serrated adenoma].

OBJECTIVE: To investigate the clinicopathological characteristics and expression status of Ki67, p53, CEA, CDX, CK7 in colorectal sessile serrated adenoma (SSA). METHODS: The clinicopathological data of 11 cases of SSA, 51 cases of hyperplastic polyp (HP) and one case with mixed HP/SSA were reviewed and analyzed retrospectively. The expression of Ki67, p53, CEA, CDX and CK7 were detected by immunohistochemistry. RESULTS: The major histological features in SSA were architectural abnormality in crypts, dilatation of serrated crypt bases like an inverted "T" or "L" shape adjacent to muscularis mucosa. Atypical cells containing round to oval nuclei and nucleoli were also observed. The immunohistochemical staining showed that the expression of p53 increased gradually from HP to TA: 11.8% in HP, 20.0% in SSA, 41.2% in VTA and 75.0% in TA, with a significant difference among the groups (chi(2) = 17.996, P = 0.000). However, no significant difference in the expression of CDX and CK7 was observed between HP and SSA. Of the 10 SSA cases, positive expression of Ki67 was found in cells located in the base or middle part of crypt in 6 cases, positive cells index was 26% - 50% in 5 cases, and > 50% in 3. Compared with the expression of Ki67 in the HP, VTA and VA, SSA showed a significant difference in both the positive cell number and in the positive regions. (positive number: chi(2) = 34.601, P = 0.000; positive regions: chi(2) = 63.077, P = 0.000). CONCLUSION: Morphological diagnosis of SSA was mainly based on crypt architectural and cellular abnormalities, and the crypt architectural abnormality may be more important than cellular features. Detection of p53 and Ki67 expression may be helpful in differential diagnosis and understanding the nature of SSA.

[Clinicopathologic features and proliferative status of colorectal serrated lesions: a study of 104 cases].

OBJECTIVE: To study the clinicopathologic features and proliferative status of colorectal hyperplastic polyp (HP), sessile serrated adenoma (SSA) and traditional serrated adenoma (TSA). METHODS: One hundred and four cases colorectal serrated lesions were collected from 2628 cases of colorectal polyps during the period from November, 2002 to December, 2007. The clinicopathologic features and expression of proliferation marker Ki-67 were studied. RESULTS: On the basis of morphologic examination, 60 cases were classified as HP, 20 cases as TSA, 11 cases as SSA, 7 cases as mixed HP/SSA/TSA, and 6 cases as mixed serrated polyp/adenoma and tubular adenoma. Immunohistochemical study for Ki-67 showed that 40 cases (78%) of the 51 cases of HP were either mostly negative or rarely (<25% cells) positive. Most of the positive cells were located at crypt bases. Among the 15 cases of TSA, 11 of them revealed positive cryptal cells (25% to 50% or>50% positivity). Most of the positive cells were located in mid portion of crypts. The number and distribution of Ki-67 positive cells in SSA were similar to those in TSA but were significantly different from those in tubular adenoma and adenocarcinoma (chi2=34.601, P=0.000; chi2=63.077, P=0.000, respectively). CONCLUSIONS: HP, SSA and TSA have their morphologic characteristics, with some overlapping features noted. The distinction between SSA and HP can be difficult. Diagnosis of SSA relies mostly on architectural rather than cytologic features. The distinction between TSA and SSA depends mainly on the presence of dysplasia. Ectopic crypt formation is almost exclusively seen in TSA. The distribution and percentage of Ki-67-positive cells are also helpful in subtyping of various colorectal serrated lesions. In general, the proliferative index is lower in serrated adenoma (TSA or SSA) than in tubular adenoma.