Brusatol attenuated proliferation and invasion induced by KRAS in differentiated thyroid cancer through inhibiting Nrf2

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) can be developed from differentiated thyroid cancer, and this dedifferentiated transformation leads to poor prognosis and high mortality. The role of Nrf2 in the dedifferentiation of differentiated thyroid cancer (DTC) induced by KRAS remains unclear.

METHODS AND MATERIALS

In this study, two DTC cell lines, BCPAP and WRO, were used to evaluate the function of Nrf2 in the dedifferentiation caused by wild-type KRAS (KRAS-WT) and G12V point mutation KRAS (KRAS-G12V).

RESULTS

The overexpression of KRAS-WT and KRAS-G12V increased the proliferative and invasive ability of BCPAP and WRO cells. Aggressive morphology was observed in KRAS-WT and KRAS-G12V overexpressed WRO cells. These results suggested that overexpression of KRAS-WT or KRAS-G12V may induce dedifferentiation in DTC cells. The expression of Nrf2 was increased by KRAS-WT and KRAS-G12V in DTC cells. In addition, compared with normal thyroid tissues, the expression of Nrf2 protein was considerably higher in thyroid cancer tissues on immunohistochemistry (IHC) staining, and the increased expression of Nrf2 indicated a poor prognosis of thyroid cancer. These results indicated that Nrf2 is the KRAS downstream molecule in thyroid cancer. Functional studies showed that the Nrf2 inhibitor Brusatol counteracted the proliferative and invasive abilities induced by KRAS-WT and KRAS-G12V in BCPAP and WRO cells. In addition, the xenograft assay further confirmed that Brusatol inhibits tumor growth induced by KRAS-WT and KRAS-G12V.

CONCLUSION

Collectively, this study suggests that Nrf2 could be a promising therapeutic target in KRAS-mediated dedifferentiation of thyroid cancer.

[Development and validation of a persistent postural-perceptual dizziness screening questionnaire]

Objective: To develop a simple screening questionnaire for persistent postural-perceptual dizziness (PPPD) and evaluate its screening ability. Methods: A convenience sample of 296 individuals who met the inclusion criteria between November 2021 and January 2023 were prospectively selected for three rounds of screening at the Vertigo Specialty Clinic of the Department of Otorhinolaryngology-Head and Neck Surgery in the First Hospital of Shanxi Medical University. In conjunction with expert opinion and statistical analysis, the first and second rounds of screening were used to modify and finalize the questionnaire entries, and the third round of screening was used to evaluate the questionnaire's screening ability. Independent sample t-test was used for inter group comparison, reliability and validity indicators were employed to screen and evaluate questionnaire entries, and the receiver operating characteristic (ROC) curve was plotted to determine the optimal cut-off value and corresponding sensitivity and specificity. Results: The final PPPD screening questionnaire entries included 21 items. In evaluating the reliability of this questionnaire, the Cronbach's alpha coefficient was 0.831, the half folding coefficient was 0.742, the content validity was 0.86, and the Kaiser-Meyer-Olkin (KMO) value in the structural validity was 0.811. Additionally, there were six factors with characteristic root>1 and a cumulative contribution rate of 62.62%. The area under the ROC curve of the screening questionnaire was 0.935 (95%CI: 0.877-0.992), and the optimal cut-off value was 8.5, with a sensitivity of 85.0%, a specificity of 85.5%, and a Kappa value of 0.653. Conclusion: The PPPD simple screening questionnaire designed in this study has a high sensitivity and specificity, making it a useful tool for identifying PPPD patients.

Targeting Nrf2 to treat thyroid cancer

Oxidative stress (OS) is recognized as a contributing factor in the development and progression of thyroid cancer. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a pivotal transcription factor involved in against OS generated by excessive reactive oxygen species (ROS). It governs the expression of a wide array of genes implicated in detoxification and antioxidant pathways. However, studies have demonstrated that the sustained activation of Nrf2 can contribute to tumor progression and drug resistance in cancers. The expression of Nrf2 was notably elevated in papillary thyroid cancer tissues compared to normal tissues, indicating that Nrf2 may play an oncogenic role in the development of papillary thyroid cancer. Nrf2 and its downstream targets are involved in the progression of thyroid cancer by impacting the prognosis and ferroptosis. Furthermore, the inhibition of Nrf2 can increase the sensitivity of target therapy in thyroid cancer. Therefore, Nrf2 appears to be a potential therapeutic target for the treatment of thyroid cancer. This review summarized current data on Nrf2 expression in thyroid cancer, discussed the function of Nrf2 in thyroid cancer, and analyzed various strategies to inhibit Nrf2.

Targeting CD36 determines nicotine derivative NNK-induced lung adenocarcinoma carcinogenesis

Smoking carcinogen nicotine-derived nitrosamine ketone (NNK) is the most potent contributor to lung adenocarcinoma (LUAD) development, but the mechanism has not been fully elucidated. Here, we reported that fatty acid translocase CD36 was significantly overexpressed in both human LUAD tissues and NNK-induced A/J mice LUAD tumors. The overexpressed CD36 was positively correlated with Src kinase activation, smoking status, metastasis, and worse overall survival of patients with smoking history. Upon NNK binding with α7 nicotinic acetylcholine receptor (α7nAChR), sarcolemmal CD36 was increased and it interacted with surface α7nAChR and cytosol Src simultaneously, which in turn activated Src and downstream pro-carcinogenic kinase ERK1/2 and Akt, and finally caused LUAD cells to form subcutaneous and pulmonary metastatic tumors. This process could be blocked by CD36 knockdown and CD36 irreversible inhibitor SSO. Furthermore, the effect of NNK was inhibited obviously in CD36-/- A/J mice. Thus, targeting CD36 may provide a breakthrough therapy of LUAD.

[Design and verification of the screening questionnaire for benign paroxysmal positional vertigo]

Objective: To design and validate a high-quality rapid screening questionnaire based on the common medical history and clinical experience of benign paroxysmal positional vertigo (BPPV). Methods: A questionnaire was designed based on expert's opinions, and the first-time patients who complained of dizziness and vertigo in the vertigo clinic of the First Hospital of Shanxi Medical University from September 2020 to June 2021 were prospectively screened. Taking the displacement test as the gold standard, the reliability and validity of the questionnaire were tested to evaluate its authenticity, reliability and benefit value. This study was divided into three steps. The first step was to conduct a pre-experiment and to adjust the questionnaire items; the second step was to determine the questionnaire items and the best cut-off value; the third step was to screen patients with the best cut-off value and to evaluate the quality of the questionnaire. Results: Seven items were finalized. The Cronbach's coefficient of the questionnaire was 0.675, the content validity was 0.85, the KMO value of the construct validity was 0.648, and there were 4 factors with characteristic root>1, and the cumulative contribution rate was 76.309%. The area under the receiver operating characteristic curve (ROC) was 0.938, and its optimal cut-off value was 4.5 points. At this point, the sensitivity was 88.89% and the specificity was 85.44%. Conclusion: The BPPV rapid screening questionnaire has high sensitivity and specificity, which can be used for clinical screening of BPPV patients.

CYP1A2 suppresses hepatocellular carcinoma through antagonizing HGF/MET signaling

Rationale: Hyperactivation of HGF/MET signaling pathway is a critical driver in liver tumorigenesis. Cytochrome P450 1A2 (CYP1A2) was significantly down-regulated in hepatocellular carcinoma (HCC). However, little is explored about its tumor suppressive role in HCC. In this study, we examined the functional mechanisms and clinical implication of CYP1A2 in HCC. Methods: The clinical impact of CYP1A2 was evaluated in HCC patients in Hong Kong cohort. The biological functions of CYP1A2 were investigated in vitro and in vivo. A series of biochemical experiments including Western blot assay, immunohistochemistry, quantitative reverse transcription-polymerase chain reaction, and Co-immunoprecipitation assay were conducted. Results: CYP1A2 expression was prominently silenced in HCC tumor tissues and the high expression of CYP1A2 was significantly correlated with lower AFP level, less vascular invasion, and better tumor-free survival in local cohort of HCC patients. The overexpression of CYP1A2 inhibited HCC cell viability and clonogenicity, reduced cell migration and invasion abilities in vitro, and suppressed tumorigenicity in vivo, whereas CYP1A2 knockdown exhibited the opposite effects. CYP1A2 significantly hindered HGF/MET signaling and Matrix metalloproteinases (MMPs) expression in HCC cells. Mechanically, CYP1A2 decreased HGF level and diminished HIF-1α expression, both of which are recognized as key regulators of MET activation. As the transcriptional activator of MET, HIF-1α was identified as a binding partner of CYP1A2. Direct binding of CYP1A2 with HIF-1α induced ubiquitin-mediated degradation of HIF-1α, inhibiting HIF-1α-mediated transcriptions. Conclusions: In conclusion, our results have identified CYP1A2 as a novel antagonist of HGF/MET signaling, and CYP1A2 may serve as an independent new biomarker for the prognosis of HCC patients.

Cytochrome P450 1A2 overcomes nuclear factor kappa B-mediated sorafenib resistance in hepatocellular carcinoma

Sorafenib resistance has become the main obstacle in the effective treatment of advanced hepatocellular carcinoma (HCC) patients. Activation of nuclear factor kappa B (NF-κB) is a newly identified mechanism that contributes to desensitized sorafenib. Cytochrome P450 1A2 (CYP1A2) functions as a tumor suppressor in HCC and its expression is negatively associated with NF-κB in the liver. This study aimed to study whether CYP1A2 could overcome sorafenib resistance. To investigate whether CYP1A2 and NF-κB p65 played roles in sorafenib desensitization, we established sorafenib-resistant (SR) HCC cells. SR cells decreased the expression of CYP1A2 along with the upregulation of NF-κB p65. CYP1A2 overexpression attenuated SR cell proliferation, increased sorafenib sensitivity, and inhibited the NF-κB pathway, whereas CYP1A2 silence showed opposite effects. Sorafenib, in combination with omeprazole, a CYP1A2 inducer, significantly hindered the growth and invasion of SR cells in vitro as well as decreased the tumor growth in vivo. The combination treatment markedly increased CYP1A2 expression and inhibited the sorafenib-induced NF-κB signaling. In addition, the overexpression of NF-κB p65 stimulated the SR cell growth and desensitized sorafenib in SR cells, where CYP1A2 overexpression reversed the phenomenon. Lastly, the majority of HCC tissue samples displayed decreased CYP1A2 but increased NF-κB p65 protein expression. Collectively, CYP1A2 can sensitize SR cells to sorafenib via inhibiting NF-κB p65 axis. Omeprazole in combination with sorafenib exerts a synergistic effect in alleviating acquired sorafenib resistance.

Nuclear FOXP3 inhibits tumor growth and induced apoptosis in hepatocellular carcinoma by targeting c-Myc

The status of FOXP3 and its isoforms in hepatocellular carcinoma (HCC) is unclear. We aimed to investigate the expression and function of FOXP3 and its isoforms in HCC. The study was performed on 84 HCC patients, HCC cell lines and a mouse tumor model. The levels of FOXP3 and its isoforms were determined by nested PCR, quantitative real-time PCR and immunohistochemistry (IHC) staining. The correlation between their levels and clinicopathologic characteristics was analyzed. The full length of FOXP3 (FOXP3) and exon 3-deleted FOXP3 (FOXP3Δ3) were found to be the major isoforms in HCC. The levels of FOXP3Δ3 mRNA and protein in HCC tumor samples were not significantly different from their adjacent normal tissues. The high expression of FOXP3 protein in HCC patients showed a good overall survival. The overexpression of FOXP3 significantly reduced tumor cell proliferation, migration and invasion. The immunofluorescence result indicated that FOXP3 needed to be translocated into the nucleus to exert its inhibitory function. The luciferase assay demonstrated that FOXP3 could be synergistic with Smad2/3/4 to inhibit the oncogene c-Myc. The co-immunoprecipitation results further revealed that FOXP3 could interact with Smad2/3/4. The chromatin immunoprecipitation (ChIP) assay showed that both FOXP3 and Smad2/3/4 bound the promoter of the c-Myc to inhibit it. The in vivo mouse tumor model study confirmed the inhibitory effect of FOXP3. Collectively, the expression of tumor FOXP3 can inhibit the growth of HCC via suppressing c-Myc directly or indirectly via interacting with Smad2/3/4. Therefore, FOXP3 is a tumor suppressor in HCC.

[Room tilt illusion: a chief complaint need to be alert in otology clinic]

Objective:This study aims to investigated the clinical significance of room tilt illusion（RTI） in screening for central vertigo in otology clinic. Method:A retrospective study of 8 RTI cases out of 656 patients with dizziness and/or vertigo. The characteristics of the symptoms, signs, physical examination, and other examinations of RTI patients were analyzed. Result:①Patients with RTI complaints accounted for 1.2% of all patients with dizziness and/or vertigo in the same period. Of all 8 patients, 2 were with acute vestibular syndrome, 5 were with episodic vestibular syndrome, and one had no dizziness and/or vertigo attack. ②Two was diagnosed with acute cerebellar infarction, and 3 was diagnosed with posterior circulation transient ischemic attacks, 2 were diagnosed with definite vestibular migraine, and one was unable to identify the cause. ③All 8 patients had a sensation of environment tilting, which was episodic（single or repeated）, transient（seconds to minutes）, in the coronal plane, and with tilt angle 30-180°. ④Seven patients had dizziness and/or vertigo for minutes to hours after a transient RTI, and one patient had no other symptoms after RTI. ⑤All patients had no decrease in vHIT gain, 6 patients had abnormal oculomotor function, and one patient had mild horizontal semicircular canal paresis. Conclusion:Patients with RTI complaints mainly had central dizziness and vertigo diseases, and once are found in otology clinic, should be alert to the possibility of suffering from central diseases.

ZBP-89 negatively regulates self-renewal of liver cancer stem cells via suppression of Notch1 signaling pathway

Liver cancer stem cells (LCSCs) initiate hepatocellular carcinoma (HCC) and contribute to its recurrence and treatment resistance. Studies have suggested ZBP-89 as a candidate tumor suppressor in HCC. We explored the role of ZBP-89 in the regulation of LCSCs. This study was performed in liver tissue samples from 104 HCC patients, 2 cell lines and mouse tumor models. We demonstrated that ZBP-89 was weakly expressed in LCSCs. Patients with high expression of LCSC markers displayed reduced survivals and higher recurrence rates after curative surgical operation. The expression of ZBP-89 was predictive for decreased recurrence. LCSC markers were negatively correlated with ZBP-89 in HCC tissues and in enriched liver tumor spheres. The exogenous expression of ZBP-89 attenuated the tumor-sphere formation and secondary colony formation capabilities of LCSCs in vitro and tumorigenicity in vivo. Furthermore, the negative effect of ZBP-89 on cancer stemness was Notch1-dependent. Localized with Notch1 intracellular domain (NICD1) in the nucleus, ZBP-89 repressed the Notch1 signaling pathway by competitive binding to NICD1 with MAML1. Collectively, ZBP-89 negatively regulates HCC stemness via inhibiting the Notch1 signaling.

[How to initially screen common central "malignant vertigo" at the bedside?]

Most of the common dizziness/vertigo diseases in otology clinic are peripheral vertigo diseases, and while about 20% -30% of all vertigo diseases are caused by central nervous system diseases. Pseudo vestibular neuritis, acute ischemic stroke with audiovestibular loss, and central paroxysmal positional vertigo are the three types of central "malignant vertigo" diseases which are most easily misdiagnosed by otologists. This article described the clinical characteristics and bedside physical performance of these three diseases, and summarized the differential diagnosis points for clinical reference.

[Clinical characteristics of LC-BPPV patients with bilateral direction-fixed horizontal nystagmus in primary Roll test]

Objective:To investigate the clinical features of LC-BPPV with direction-fixed horizontal nystagmus in the primary Roll test. Method:Nine patients of LC-BPPV with bilateral direction-fixed horizontal nystagmus in the first Roll test were treated by repositioning maneuvers after judging the affected side and the prognosis was observed. Result:The affected side of eight patients was the side of the apogeotropic nystagmus. Barbecue or Gufoni maneuvers was effective for reposition. The other one had no conversion of nystagmus and could not judge the affected side. Conclusion:The nystagmus performance of patients with LC-BPPV is complicated. It is necessary to carefully analyze the nystagmus performance of each position. Combining with bow and lean test, lying down test and null plane, the position of the otolith is inferred. Comprehensive use of the Barbecue or Gufoni maneuvers, forced side lying on the affected side, mastoid sniper, shaking head method is effective to complete the reposition treatment.

The expression of FOXP3 and its role in human cancers

FOXP3 is a transcription factor, which belongs to the family of FOX protein. FOXP3 was initially discovered in regulatory T cells and supposed to play a significant role in the process of regulatory T cell differentiation. Increasing evidence has shown that FOXP3 is also expressed in tumor cells. However, the results of tumor FOXP3 is inconsistent and even the opposite. In some types of human cancers, the expression of FOXP3 is upregulated, and it can promote the development of cancers, leading to a poor prognosis. While in some other types of cancers, it is a different story. The reason for the contradictory data is unknown. The discovery of FOXP3 isoforms, interaction between tumor cells and lymphocytes in the tumor microenvironment, subcellular location, and mutation of FOXP3 may provide some clues. In this review, we first summarize and analyze the recent development. The final section focuses on the regulation of FOXP3 expression.

[The clinical characteristics of the evoked nystagmus in the non-affected side during Dix-Hallpike test in the unilateral posterior semicircular canal benign paroxysmal positional vertigo]

Objective: To investigate the clinical characteristics of the evoked nystagmus in the non-affected side during Dix-Hallpike test(D-H test)in unilateral posterior semicircular canal benign paroxysmal positional vertigo(PC-BPPV). Method: Two hundred and thirty-six patients were diagnosed with unilateral PC-BPPV in the Tinnitus and Dizziness clinic.Among them,14 patients exhibited positive nystagmus when the non-affected side was stimulated by D-H test. The clinical data from this subgroup of patients were retrospectively analyzed. Result: The upbeat and torsional nystagmus of 14 patients were all evoked by D-H test in the affected side. 11 cases were right PC-BPPV and 3 cases were left PC-BPPV. Among these 14 patients, 5 patients exhibited the upbeat and torsional nystagmus during D-H test in the non-affected side, which was in the same direction as that evoked in the affected side. Among them, 4 cases were right PC-BPPV and 1 case was left PC-BPPV. However, the downbeat nystagmus of the remaining 9 patients were evoked by D-H test in the non-affected side, in which 7 cases were right PC-BPPV and 2 cases were left PC-BPPV.The nystagmus and vertigo of all patients completely disappeared after performing the Epley or Semont repositioning maneuvers on the affected side. Conclusion: The bilateral positive nystagmus of unilateral PC-BPPV can be evoked by D-H test. The form of nystagmus on the non-affected side is related with the initial position of otoconia in affected semicircular canal and the moving direction of otoconia during the positional test. It is effective to perform Epley or Semont repositioning maneuvers on the affected side. Meanwhile, both the effect of maneuvers and the type of nystagmus evoked by D-H test can verify which side is affected.

[Effects of four different nasal packing materials after endoscopic sinus surgery]

Objective:To investigate effects of four different types of nasal packs after endoscopic sinus surgery. Method:Sixty patients with chronic rhinosinusitis who underwent endoscopic sinus surgery were evaluated preoperatively using visual analog symptom scale, Lund-Kennedy endoscopy scoring scale, and Lund Mackay CT scoring scale.All patients received nasal packing after operative, and divided into four groups based on the nasal packs used: nasopore group (16 cases), merocel group (16 cases), vaseline gauze group(16 cases) and merocel with vaseline gauze group(12 cases). All packs were removed 48 to 72 hour after the surgery. Clinical effects of four nasal packs were evaluated based on following indexes: pain after twelve hours of nasal packing, bleeding during nasal packing, pain and bleeding during packing removal, difficulty of packing removal. Result:The lowest degree of forementioned five different indexes was found in Nasopore group, and was significantly different with other three groups(P <0.05), merocel produced the highest bleeding during nasal packing,which had significant difference with other three groups(P <0.05), vaseline gauze produced the highest pain during nasal packing and packing removal, which had significant difference with other three groups(P <0.05), merocel combined vaseline gauze had no significant difference with merocel on the pain during nasal packing and packing removal(P >0.05), and it had no significant difference with vaseline gauze on bleeding during nasal packing, bleeding upon packing removal and degree of difficulty or ease upon packing removal(P >0.05).Conclusion:As a new type of high expansion absorbable nasal packing products applied after FESS, nasopore has the advantages of good hemostatic effect,higher nasal comfort level,least bleeding upon packing removal and so on. At the same time, the implementation of personalized mixed nasal packing of different materials could make up for the various defects when used alone,gained better clinical effect and worthy of clinical popularization and application.

Crosstalk between prognostic long noncoding RNAs and messenger RNAs as transcriptional hallmarks in gastric cancer

AIM

Our study investigated the significance of the crosstalk between long noncoding RNAs (lncRNAs) and mRNAs in gastric cancer (GC).

METHODS

lncRNA and mRNA expression profiling data in 671 GC tumors and 77 nontumorous gastric tissues were retrieved from the gene expression omnibus database: GSE54129, GSE13911, GSE19826, GSE79973, GSE15459 and GSE66229. Differentially expressed analysis, RNA coexpression network construction, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were conducted in this study.

RESULTS

Using differentially expressed and prognostic lncRNAs or mRNAs in GC, we constructed the lncRNA-mRNA coexpression networks. This network involved with vital GO and KEGG pathways.

CONCLUSION

Our study reveals coexpressed lncRNAs and mRNAs as transcriptional hallmarks in GC patients which provide interesting information regarding the incidence and outcome of GC.

O-GlcNAc transferase promotes fatty liver-associated liver cancer through inducing palmitic acid and activating endoplasmic reticulum stress

BACKGROUND & AIMS

O-GlcNAc transferase (OGT) is a unique glycosyltransferase involved in metabolic reprogramming. We investigated the functional role of OGT in non-alcoholic fatty liver disease-associated hepatocellular carcinoma (NAFLD-HCC).

METHODS

The biological function of OGT in NAFLD-HCC was determined by gain- or loss- of OGT functional assays in vitro and in nude mice. OGT target factors and pathways were identified by liquid chromatography-tandem mass spectrometry (LC-MS), promoter luciferase assay, DNA binding activity assay and Western blot.

RESULTS

OGT was upregulated in 12 out of 18 (66.7%) NAFLD-HCC tumor tissues by transcriptome sequencing, which was confirmed in additional NAFLD-HCC tumor tissues and cell lines. Biofunctional investigation demonstrated that OGT significantly increased cell growth (p<0.001), clonogenicity (p<0.01), migration and invasion (p<0.05) ability in vitro, and promoted xenograft tumor growth as well as lung metastasis in nude mice. The oncogenic effect of OGT was investigated, we found that OGT significantly induced palmitic acid production identified by LC-MS, which enhanced the protein expression of endoplasmic reticulum (ER) stress masters of glucose-regulated protein 78 and inositol-requiring enzyme 1α. Consequently, OGT significantly activated JNK/c-jun/AP-1 cascade by increasing protein expression of p-JNK, p-c-Jun and activation of AP-1; and induced NF-κB pathway through enhancing the protein levels of p-IKKα/ p-IKKβ, p-p65, p-p50 and the NF-κB DNA binding activity. Notably, OGT inhibition by its antagonist (ST045849) suppressed cell proliferation in vitro (p<0.001) and in xenograft mice models (p<0.05).

CONCLUSIONS

OGT plays an oncogenic role in NAFLD-associated HCC through regulating palmitic acid and inducing ER stress, consequently activating oncogenic JNK/c-jun/AP-1 and NF-κB cascades.

LAY SUMMARY

OGT, a unique glycosyltransferase enzyme, was identified to be upregulated in non-alcoholic fatty liver disease-associated hepatocellular carcinoma tissues by transcriptome sequencing. Here, we found that OGT plays a role in cancer by promoting tumor growth and metastasis in both cell models and animal models. This effect is mediated by the induction of palmitic acid.

[Expression and significance of serum hepatocyte growth factor and myeloperoxidase in patients with obstructive sleep apnea hypopnea syndrome]

Objective:The aim of this study is to explore the expression and significance of serum HGF and MPO in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) in adults. Method:Ninety-six cases of OSAHS patients diagnosed by PSG were divided into 3 groups: Heavy, medium and light according to the range of AHI; 32 cases of outpatients were healthy persons as the control group. The serum HGF and MPO were determined by ELISA; HGF and MPO were measured after comprehensive treat with CPAP in patients with severe OSAHS, and the correlation between HGF, MPO and PSG were analyzed. Result:①With the severity of OSAHS patients increased, the serum levels of HGF and MPO increased gradually (F=119.006, 25.138; P<0.05); The concentration of HGF and MPO in each group showed that there was no significant difference between the two groups compared with the control group (P>0.05); The rest of the two groups were significantly different (P<0.05). ②There was no correlation between serum levels of HGF, MPO, BMI and age in OSAHS patients (P>0.05). The change of serum concentration was positively related to the two. All were negatively correlated with AHI, and positively correlated with LSaO₂ (P<0.05). ③LSaO₂ of 32 patients with severe OSAHS of has significantly increased after 3 months of comprehensive treatment, AHI and peripheral blood HGF, MPO levels were significantly reduced (P<0.05). The amylin and myeloperoxidase concentrations of blood after 6 months of treatment were significantly lower than those of 3 months after treatment (P<0.05), which still increased compared with the control group. Conclusion:Surgery combined with CPAP treatment can significantly reduce the degree of hypoxia and cardiovascular damage in OSAHS patients, which was significantly correlated with the treatment time. Combined detection of serum HGF and MPO concentrations in patients with OSAHS has a certain clinical value in judging the condition and curative effect and evaluating the cardiovascular damage.

Identification of prognostic and subtype-specific potential miRNAs in thymoma

AIM

We performed a study to identify the role of microRNA in thymoma.

PATIENTS & METHODS

One hundred twenty-three thymoma patients with clinical information and miRNA expression data from The Cancer Genome Atlas were included in the study. Comprehensive bioinformatics analysis was integrated in our analysis.

RESULTS & CONCLUSION

Seven miRNAs were found to be associated with overall survival (p < 0.001). Another four miRNAs were found to be associated with disease-free survival (p < 0.001). Type C thymoma can be distinguished from nontype C thymoma by miRNAs. Interestingly, seven miRNAs showed both prognostic and subtype-specific potential. Our findings suggest that miRNAs can be used for prognostic prediction and subtype stratification.

[Clinical research of differences of volume of pharyngeal cavity between normal healthy subjects and patients with severe obstructive sleep apnea hypopnea syndrome]

Objective:To investigate the differences of volume of pharyngeal cavity between normal healthy subjects and patients with severe obstructive sleep apnea hypopnea syndrome(OSAHS)before and after surgery and its application value in assessment of surgical curative effect.Method:Forty-four healthy male adults were included in normal group.Thirty-eight patients with severe OSAHS diagnosed by polysomnography were included in experimental group(OSAHS group). Volume of pharyngeal cavity, oropharynx and laryngopharynx measured by acoustic pharyngealmetry and AHI, obstructive apnea frequency and the lowest oxygen saturation recorded by PSG monitor were all obtained in normal groups and experimental groups before and 3 months after the surgery. All the data are statistically analyzed. Result:Volume of pharyngeal cavity,AHI,obstructive apnea frequency and lowest oxygen saturation of patients in experimental group were all improved after surgery compared with pre-operation(P<0.01). Conclusion: The measurement of pharyngeal cavity volume is helpful to the quantitative analysis of upper airway structure and determine the stenosis location, it is also useful to guide surgery and evaluate the curative effect of the surgery.

Preoperative serum α-fetoprotein and prognosis after hepatectomy for hepatocellular carcinoma

Background

While the majority of studies report that a raised serum α-fetoprotein (AFP) level before operation is associated with a high risk of recurrence and death in patients who undergo hepatectomy for hepatocellular carcinoma (HCC), results are conflicting. The aim of this study was to assess the prognostic value of AFP.

Methods

Serum AFP levels were measured in patients with hepatitis-associated HCC who underwent hepatectomy between 1995 and 2012. Kaplan–Meier and multivariable analyses were performed to identify risk factors for overall and disease-free survival. Univariable and multivariable Cox proportional hazards regression was used to evaluate the predictive value of AFP. Receiver operating characteristic (ROC) curves were generated to identify the AFP level that had the highest accuracy in discriminating between survivors and non-survivors.

Results

Some 376 patients with hepatitis B virus (HBV)-associated HCC were included in the study. The overall survival rate was 58·8 per cent in patients with an AFP level of 400 ng/ml or less compared with 40·4 per cent for those with a level exceeding 400 ng/ml (P = 0·001). AFP concentration above 400 ng/ml was an independent risk factor for shorter disease-free and overall survival after surgery. ROC analysis indicated that the optimal cut-off values for AFP varied for different subtypes of HCC. The sensitivity and specificity were lower with areas under the ROC curve of less than 0·600. An AFP level greater than 400 ng/ml was not sensitive enough to predict the prognosis in patients with an HCC diameter smaller than 3 cm.

Conclusion

A serum AFP level above 400 ng/ml predicts poor overall and recurrence-free survival after hepatectomy in patients with HBV-associated HCC. AFP is not a strong prognostic marker given its poor discriminatory power, with low sensitivity and specificity.

A molecular model for neurodevelopmental disorders

Genes implicated in neurodevelopmental disorders (NDDs) important in cognition and behavior may have convergent function and several cellular pathways have been implicated, including protein translational control, chromatin modification, and synapse assembly and maintenance. Here, we test the convergent effects of methyl-CpG binding domain 5 (MBD5) and special AT-rich binding protein 2 (SATB2) reduced dosage in human neural stem cells (NSCs), two genes implicated in 2q23.1 and 2q33.1 deletion syndromes, respectively, to develop a generalized model for NDDs. We used short hairpin RNA stably incorporated into healthy neural stem cells to supress MBD5 and SATB2 expression, and massively parallel RNA sequencing, DNA methylation sequencing and microRNA arrays to test the hypothesis that a primary etiology of NDDs is the disruption of the balance of NSC proliferation and differentiation. We show that reduced dosage of either gene leads to significant overlap of gene-expression patterns, microRNA patterns and DNA methylation states with control NSCs in a differentiating state, suggesting that a unifying feature of 2q23.1 and 2q33.1 deletion syndrome may be a lack of regulation between proliferation and differentiation in NSCs, as we observed previously for TCF4 and EHMT1 suppression following a similar experimental paradigm. We propose a model of NDDs whereby the balance of NSC proliferation and differentiation is affected, but where the molecules that drive this effect are largely specific to disease-causing genetic variation. NDDs are diverse, complex and unique, but the optimal balance of factors that determine when and where neural stem cells differentiate may be a major feature underlying the diverse phenotypic spectrum of NDDs.

miR-625 suppresses tumour migration and invasion by targeting IGF2BP1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies and the third leading cause of cancer-related deaths worldwide. Tumour metastasis is one of the major causes of high mortality. microRNAshave been implicated in HCC metastasis. In this study, we found that miR-625 was frequently downregulated in HCC samples. A decrease in miR-625 was significantly correlated with lymph node anddistance metastasis (P=0.013), the presence of portal venous invasion (P=0.036), tumor-node-metastasis (TNM) stage (P=0.027) and unfavourable overall survival (P=0.003). Compared with primary tumours, miR-625 expression was markedly reduced in portal venous metastatic tumours. Re-expression of miR-625 in HCC cells was remarkably effective in suppressing cell migration andinvasiveness in vitro and in vivo. Mechanistically, miR-625 was confirmed to downregulate IGF2 mRNA-binding protein 1(IGF2BP1) directly, the expression of which was inversely correlated with the level of miR-625 in HCC cell lines and tissues. High expression of IGF2BP1 was frequently found in HCC samples, and associated with poor prognosis. Knockdown of endogenous IGF2BP1 by siRNA exhibited similar effects as the overexpression of miR-625, whereas overexpression of IGF2BP1 (without the 3'-UTR) abrogated miR-625-mediated metastasis inhibition. Interference of the PTEN/HSP27 pathway contributed to miR-625-mediated metastasis inhibition. Taken together, our data suggest that miR-625 might function as an antimetastatic miRNA to have an important role in HCC progression by modulating the IGF2BP1/PTEN pathway. The newly identified miR-625/IGF2BP1 axis represents a new potential therapeutic target for HCC treatment.

HBx mutants differentially affect the activation of hypoxia-inducible factor-1α in hepatocellular carcinoma

BACKGROUND

Mutations in HBx gene are frequently found in HBV-associated hepatocellular carcinoma (HCC). Activation of hypoxia-inducible factor-1α (HIF-1α) contributes to HCC development and progression. Wild-type HBx has been demonstrated to activate HIF-1α, but the effect of HBx mutations on HIF-1α has not been elucidated.

METHODS

HBx mutations were identified by gene sequencing in 101 HCC tissues. Representative HBx mutants were cloned and transfected into HCC cells. Expression and activation of HIF-1α were analysed by western blot and luciferase assays, respectively. The relationship between HBx mutants and HIF-1α expression in HCC tissues was also evaluated.

RESULTS

The dual mutations K130M/V131I enhanced the functionality of HBx as they upregulated the expression and transcriptional activity of HIF-1α. The C-terminal truncations and deletion mutations, however, weakened the ability of HBx to upregulate HIF-1α. Meanwhile, the C-terminus was further found to be essential for the stability and transactivation of HBx. In the HCC tissues, there was a positive association between the HBx mutants and HIF-1α expression.

CONCLUSION

Different mutations of HBx exert differentiated effects on the functionality of HIF-1α, however, the overall activity of HBx mutants appears to increase the expression and transcriptional activity of HIF-1α.

Hepatitis B virus x protein induces autophagy via activating death-associated protein kinase

Hepatitis B virus x protein (HBX), a product of hepatitis B virus (HBV), is a multifunctional protein that regulates viral replication and various cellular functions. Recently, HBX has been shown to induce autophagy; however, the responsible mechanism is not fully known. In this study, we established stable HBX-expressing epithelial Chang cells as the platform to study how HBX induced autophagy. The results showed that the overexpression of HBX resulted in starvation-induced autophagy. HBX-induced autophagy was related to its ability to dephosphorylate/activate death-associated protein kinase (DAPK). The block of DAPK by its siRNA significantly counteracted HBX-mediated autophagy, confirming the positive role of DAPK in this process. HBX also induced Beclin 1, which functions at the downstream of the DAPK-mediated autophagy pathway. Although HBX could activate JNK, a kinase known to participate in autophagy in certain conditions, the change in JNK failed to influence HBX-induced autophagy. In conclusion, HBX induces autophagy via activating DAPK in a pathway related to Beclin 1, but not JNK. This new finding should help us to understand the role of autophagy in HBX-mediated pathogenesis and thus may provide targets for intervening HBX-related disorders.

Downregulation of polo-like kinase 4 in hepatocellular carcinoma associates with poor prognosis

Polo-like kinase 4 (PLK4), belonging to serine/threonine kinase family, is critical for centriole replication and cell cycle progression. PLK4 has been proposed as a tumor suppressor in hepatocellular carcinoma (HCC). However, its expression and significance in HCC have not been well studied. In the present study, we found that PLK4 was markedly downregulated in both HCC cell lines and fresh cancer tissues, using quantitative real-time-PCR and western blot. Immunohistochemistry data also revealed that decreased expression of PLK4 was present in 72.4% (178/246) of HCC tissues, compared with the corresponding adjacent nontumorous tissues. Furthermore, PLK4 expression significantly correlated with clinicopathological parameters, including clinical stage (P=0.034), serum α-fetoprotein (AFP) (P=0.019) and tumor size (P=0.032). Moreover, HCC patients with low PLK4 expression survived shorter than those with high PLK4 expression, as indicated by overall survival (P=0.002) and disease-free survival (P=0.012) assessed by the Kaplan-Meier method. In addition, multivariate analysis suggested PLK4 as an independent predictor of overall survival (HR, 0.556; 95%CI, 0.376-0.822; P=0.003) and disease-free survival (HR, 0.547; 95%CI, 0.382-0.783; P=0.001). Collectively, our study demonstrated that PLK4 was remarkably downregulated in HCC and could be served as a potential prognostic marker for patients with this deadly disease.

Abstract 4013: The positive role of TPγ in the induction of COX-2, TxA2 and cell growth by NNK in human lung cancer cells

Many studies have shown that 4-Methylnitrosamino-1-3-pyridyl-1-butanone (NNK), the most potent carcinogen present in tobacco smoke, can induce lung tumor growth. We previously demonstrated that the activation of extracellular regulated protein kinases (ERK) and cAMP response element-binding protein (CREB) is responsible for the pro-survival and proliferative effects of thromboxane A2 (TxA2) and its receptor (TP) in the human lung cancer cells stimulated with NNK (reported in oncogene journal). In current study, we further determined the role of cyclooxygenase(COX)-2/TxA2/TP pathway in lung cancer cell growth mediated by NNK. TP exists as two isoforms, ≤ and β, in human beings. Western blotting showed that TPα, but not TPα, was widely expressed in a series of human lung cells. NCI-H23 and CRL-2066, which express both TPγ and TPα, were selected as models in this study. COX-2 inhibitor NS398 could significantly reduce NNK-stimulated TxA2 synthesis. Moreover, NS398 and BM567, an agent combining TxA2 synthase inhibition and TP antagonism, had the similar effects to reverse NNK-induced activation of ERK and CREB and the increase in cell growth. Furthermore, the administration of TxA2 mimetic U46619 could almost reconstituted NNK-induced ERK and CREB activation in the presence of COX-2-siRNA. Collectively, these findings suggest that in lung cancer cells stimulated with NNK, TxA2 is mainly derived from COX-2 and acts as a key mediator for tumor-promoting effects of COX-2. Interestingly, TP antagonist SQ29548 could inhibit NNK-induced COX-2 protein expression and TxA2 production, indicating that TP is able to modulate NNK-induced COX-2 expression and activity, thereby constituting an auto-amplification mechanism of TxA2 synthesis in lung cancer cells stimulated with NNK. We further examined which TP isoform contributes to the NNK effects. We observed that the protein expression of TPα, but not TPα, was time-dependently increased by NNK. Moreover, the activation of ERK and CREB and the production of COX-2 and TxA2 by NNK were potentiated in cells transfected with pcDNA3-TPγ as compared with cells transfected with control vector or pcDNA3-TPα, and such effects could be reversed by SQ29548. However, in cells transfected with pcDNA3-TPα, the COX-2, TxA2, phospho-ERK and phospho-CREB levels were similar to that seen in the cells transfected with control vector, and neither NNK nor SQ29548 had any additional effects when compared to the control cells. Taken together, these data strongly suggest that TPγ rather than TPγ is, at least in part, responsible for the induction of COX-2, TxA2 and cell growth by NNK in lung cancer cells. Our study implies that targeting TxA2 and its receptor TPγ may represent a promising strategy for prevention of smoking-associated lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4013. doi:1538-7445.AM2012-4013

Dihydroartemisinin exhibits antitumor activity toward hepatocellular carcinoma in vitro and in vivo

Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has been shown to exhibit inhibitory effects on human cancer cells. However, its antitumor ability toward hepatocellular carcinoma (HCC) has not been studied. In this study, we demonstrated that DHA significantly inhibited HCC cell growth in vitro and in vivo via inducing G2/M cell cycle arrest and apoptosis. The induction of p21 and the inhibition of cyclin B and CDC25C contributed to DHA-induced G2/M arrest. DHA-induced apoptosis was associated with mitochondrial membrane depolarization, release of cytochrome c, activation of caspases, and DNA fragmentation. Activation of caspase 9 and caspase 3, but not caspase 8, was detected in DHA-treated cells. Attenuation of apoptosis in cells pretreated with Z-VAD-FMK suggested the involvement of caspase cascade. Furthermore, p53 facilitated apoptosis caused by DHA. Bcl-2 family proteins were also responsible for DHA-induced apoptosis. DHA exposure decreased Mcl-1 expression but increased the levels of Noxa and active Bak. Bak was released from the Mcl-1/Bak complex due to the decline of Mcl-1. Further study revealed that Mcl-1 was rapidly degraded in DHA-treated cells and that DHA-induced apoptosis was largely inhibited by overexpression of Mcl-1 or RNAi-mediated decrease of Bak and Noxa. In a HCC-xenograft mouse model, the intraperitoneal injection of DHA resulted in significant inhibition of HCC xenograft tumors. Taken together, our data, for the first time, demonstrate the potential antitumor activity of DHA in HCC.

Bid stands at the crossroad of stress-response pathways

Bid, a BH3-only Bcl-2 family member, is proven to be a pivotal molecule for the regulation of tumorigenesis by its multiple functions in promoting apoptosis, survival and proliferation. Growing evidence supports that Bid has double roles with respect to stress-response. In most cases it functions in a truncated form, but the cleavage of Bid may not be an absolute requirement for Bid to be pro-apoptotic. Full-length Bid can also translocate to and activate the mitochondria without cleavage. Bid has emerged as a central player linking death signals through surface death receptors to the core apoptotic mitochondrial pathway. Bid is also involved in DNA damage response, and the phosphorylated Bid may negatively regulate its pro-apoptotic function independent of the BH3 domain. This review surveys recent developments in understanding the molecular mechanisms of Bid activation and its roles in regulating the cross-talk of cell cycle arrest and apoptosis.

4-Methylnitrosamino-1-3-pyridyl-1-butanone (NNK) promotes lung cancer cell survival by stimulating thromboxane A2 and its receptor

The role of thromboxane A(2) (TxA(2)) in smoking-associated lung cancer is poorly understood. This study was conducted to study the role of TxA(2) in smoking carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-promoted cell survival and growth in human lung cancer cells. We found that NNK increased TxA(2) synthase (TxAS) expression and thromboxane B(2) (TxB(2)) generation in cultured lung cancer cells, the result of which was supported by the increased level of TxAS in lung cancer tissues of smokers. Both TxAS-specific inhibitor furegrelate and TxA(2) receptor antagonist SQ29548 completely blocked NNK-mediated cell survival and growth via inducting apoptosis. TxA(2) receptor agonist U46619 reconstituted a near-full survival and growth response to NNK when TxAS was inhibited, affirming the role of TxA(2) receptor in NNK-mediated cell survival and growth. Suppression of cyclic adenosine monophosphate response element binding protein (CREB) activity by its small interference RNA blocked the effect of NNK. Phosphatidylinositol 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK) also had a positive role. Altogether, our results have revealed that NNK stimulates TxA(2) synthesis and activates its receptor in lung cancer cells. The increased TxA(2) may then activate CREB through PI3K/Akt and extracellular ERK pathways, thereby contributing to the NNK-promoted survival and growth of lung cancer cells.

Abstract 3088: Mammalian sterile-20 like kinase 1(Mst1) upregulates cyclin D1 to promote hepatocellular carcinoma cell growth

Although hepatocellular carcinoma (HCC) is highly related to the chronic infection of hepatitis B or C viruses, the progression of the malignancies is caused by the increased proliferation of the HCC cells. The proliferation of tumor cells is usually resulted from dysregulations in cell cycle progression or apoptosis induction. Current evidence indicates that the cytoplasmic serine/threonine kinase Mammalian Sterile-20 like kinase 1 (Mst1) suppresses HCC development by inactivating the oncoprotein YAP65 in normal livers. Furthermore, upon DNA damage, the caspase cleavage of the full-length cytoplasmic Mst1 proteins is activated, which then leads to Mst1 nuclear translocation and apoptosis induction via transcriptional activation of the Forkhead tumor suppressor Foxo3a. Using an HCC cell line model, the Hep3B cells, we found that transient transfection of Mst1 did not induce apoptosis, but rather enhanced the cellular proliferation by 74% within 2 days after transfection. The growth-promoting activity of Mst1 in the HCC cells was confirmed as Hep3B cell growth was significantly reduced by transient expression of the Mst1 kinase dead mutant (26% reduction) or Mst1 specific shRNAs (62% reduction). The Mst1-induced cell proliferation was further evidenced by the presence of Ki67 nuclear staining in the transfected Hep3B cells while the cells expressing the kinase dead mutant of Mst1 did not have Ki67 nuclear staining. Moreover, Western blot analyses showed that phosphorylation of YAP65 was not dependent upon Mst1 overexpression, suggesting that the hippo pathway was not involved in the Mst1 induced cell proliferation. Interestingly, Western blotting showed that such a growth-promoting activity of Mst1 in Hep3B cells was associated with a sustained upregulation of Cyclin D1 expression, an important marker for proliferation, after Mst1 overexpression. Our findings suggest that an alteration of Mst1 function exists in HCC cells, which drives aberrant HCC proliferation via Cycin D1 upregulation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3088.

Therapeutic effect of alpha-fetoprotein promoter-mediated tBid and chemotherapeutic agents on orthotopic liver tumor in mice

Previous studies have shown that the application of Ad/AFPtBid significantly and specifically killed hepatocellular carcinoma (HCC) cells in culture and subcutaneously implanted in mice. This study was to test the therapeutic efficacy of Ad/AFPtBid in an orthotopic hepatic tumor model. Four weeks after implantation of tumor cells into the liver, nude mice were treated with Ad/AFPtBid alone or in combination with 5-fluorouracil (5-FU). Serum alpha-fetoprotein (AFP) was measured as a marker for tumor progression. The results showed that Ad/AFPtBid significantly inhibited Hep3B tumor growth. Ad/AFPtBid and 5-FU in combination was more effective than either agent alone. Tumor tissues of Ad/AFPtBid alone or combination treatment groups showed a decrease in cells positive for proliferation cell nuclear antigen, but an increase in apoptosis. Ad/AFPtBid did not suppress the hepatic tumor formed by non-AFP-producing hepatoma SK-HEP-1 cells or colorectal adenocarcinoma DLD-1 cells. The survival rate was higher in mice treated with Ad/AFPtBid plus 5-FU than those treated with either agent alone. No acute toxic effect was observed in mice receiving Ad/AFPtBid. Collectively, Ad/AFPtBid can specifically target and effectively suppress the AFP-producing orthotopic liver tumor in mice without obvious toxicity, indicating that it is a promising tool in combination with chemotherapeutic agents for treatment of AFP-producing HCC.

Association of p53 with Bid induces cell death in response to etoposide treatment in hepatocellular carcinoma

Appropriate subcellular localization of proteins is crucial for regulating their functions. Both p53 and the BH3-only Bid play roles in the development and the treatment of hepatocellular carcinoma (HCC). They both participate in the cross talk of cell cycle arrest and apoptosis in response to DNA damage. However, some important issues related to their pathways are not yet resolved. Bid genomic loci contain p53-binding DNA response elements and Bid can mediate p53-dependent transactivation. Here, we showed that etoposide-induced DNA damage could significantly induce p53 and Bid nuclear export. When cells were stimulated by etoposide, p53 could, through the association with Bid, cause translocation of Bid from the nucleus to the cytoplasm and on to its ultimate location in the mitochondria. p53 was physically associated with Bid, and both p53 and Bid cooperatively promoted cell death induced by etoposide. Knockdown of Bid expression notably attenuated cell death induced by etoposide and also released p53 from the mitochondria. These findings reveal a novel mechanism by which p53 is associated with Bid in the nucleus to facilitate exportation of Bid to the mitochondria and induce apoptosis in response to etoposide-induced DNA damage in HCC.

[Effect of 5F from Pteris semipinnata on expression of Nr1d1 in HO-8910PM cell line]

OBJECTIVE

To investigate the effects of PsL5F (ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid, an extract from Pteris semipinnata L) on the expression of nuclear receptor subfamily 1, group D, member 1 (Nr1d1) in highly metastatic ovarian carcinoma HO-8910PM cells, and its mechanisms.

METHOD

Microarray Chip was used to examine the level of Nr1d1 mRNA expression on HO-8910PM cells treated with PsL5F. Fluorescent quantitative real-time PCR assay and Western blot were performed to verify the effects of PsL5F on Nr1d1 mRNA and protein expression.

RESULT

After 24 h treatment of 100 micromol x L(-1) PsL5F, the mRNA and protein levels of Nr1d1 in HO-8910PM cells were 35.34 +/- 1.07 and 7.71 +/- 0.43 times compared to those of control group (P < 0.01, P < 0.01), respectively.

CONCLUSION

PsL5F can up-regulate significantly the expression of Nr1d1 in HO-8910PM cells. Antitumor effects and its mechanisms of PsL5F in HO-8910PM cells may be involved in the up-regulation of Nr1d1 expression.

Nucleophosmin/B23 interacts with p21WAF1/CIP1 and contributes to its stability

The cyclin-dependent kinase inhibitor p21(WAF1/CIP1) is a critical regulator of cell cycle, and it is easily degraded by proteasome through ubiquitin-dependent and -independent pathway. The mechanism of the post-translational regulation of p21 stability remains to be further clarified. In the present study, we have identified nucleophosmin (NPM)/B23, a multifunctional protein that bound p21 and contributed to its stability. The direct interaction between p21 and NPM was confirmed by reciprocal co-immunoprecipitation and GST pull-down assay. Confocal microscopy showed that NPM partially co-localized with p21 in nucleoplasm and their co-localization increased treated with Act D which induces the nucleoplasmic translocation of NPM. We observed the half life of p21 was prolonged with overexpression of NPM or Act D treatment. Knockdown of NPM by siRNA resulted in downregulation of p21 and impaired upregulation of p21 treated with Act D. Further, we examined the effect of NPM expression on the ubiquitination of p21. Overexpression of NPM inhibited the ubiquitination of p21, and depletion of NPM remarkably improved the ubiquitination of p21. Altogether, we provide evidence for a direct binding between NPM and p21, and assign NPM as a positive post-translational regulator of p21.

[Studies on quality standard of PsL 5F injections]

OBJECTIVE

To establish the quality standard of PsL injections containing mainly 5F (ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid).

METHOD

The identification of PsL was performed by thin-layer chromatography, and the content was determined by HPLC. The column was Hypersil C18 (4.6 mm x 250 mm, 5 microm), the mobile phase was the mixture of methane-water-acitic acid (55:45: 0.045) with a flow rate of 1.0 mL x min(-1), the detective wavelength was 254 nm, and the column temperature was maintained at 35 degrees C. The pH value and K+ content of the three batchs injection were determined with pH meter and flame photometric meter, and the contents of tannin, protein, oxalic acid salt and heavy metals were detected by deferent methods.

RESULT

The TLC method was suitable for the identification of PsL5F. The linearity for 5F was obtained over the range of 30-240 microg x mL(-1) (r = 0.999 8), the average recovery of 5F was 99.8%. The injections were of pH value range from 7.80 to 8.20, K+ contents less than 10 mmol x L(-1), and the contents of tannin, protein, oxalic acid salt and heavy metals were qualified with the Chinese pharmacopoeia, respectively.

CONCLUSION

It's sensitive and reliable that can be used as quality control methods of PsL5F injections.

Mechanisms of lymphocyte loss in SARS coronavirus infection

1. Human lymphocytes and monocytes are not permissive to productive SARS coronavirus (SARS-CoV) infection in vitro. 2. Challenge of lymphocytes and monocytes with infectious SARS-CoV, inactivated virions, and receptor-binding fragment of spike protein does not trigger apoptosis. 3. Direct infection/interaction between viruses and lymphocytes/monocytes is unlikely to be the cause of lymphopaenia in SARS patients. 4. Lymphopaenia in SARS patients is likely to result from indirect mechanisms secondary to the viral infection.

Haem oxygenase-1 plays a central role in NNK-mediated lung carcinogenesis

The tobacco-specific nitrosamine, 4-(N-methyl-N-nitrosoamino)-1-(3-pyridyl)-1-butanone (NNK), is a potent lung cancer inducer. However, how NNK induces lung cancer is still largely unknown. Haem oxygenase (HO)-1 was evaluated in 30 pairs of lung cancer tumour samples and matched nontumour tissues from patients with a history of cigarette smoking. Expression of HO-1, p21(Cip1/Waf1/Cid1) (p21), B-cell lymphoma (Bcl)-2 family members, mitogen-activated protein kinase and nuclear factor (NF)-kappaB was also studied in lung cancer cells treated with NNK. The levels of HO-1 and p21 were significantly increased in lung tumour tissues. There was a positive relationship between these two proteins in the tumour. NNK stimulated lung cell proliferation and elevated the levels of HO-1, p21, inhibitor of apoptosis protein (c-IAP)2 and Bcl-2, but downregulated Bad. These effects of NNK were blocked by zinc protoporphyrin-XII, an HO-1 inhibitor. The NNK-mediated expression of HO-1 was governed by NF-kappaB and extracellular signal-regulated kinase 1/2, since blocking either of these prevented the stimulatory effect of NNK on HO-1, as well as molecules downstream of HO-1, such as p21, c-IAP2, Bcl-2 and Bad. In conclusion, haem oxygenase-1 plays a central role in NNK-mediated cell proliferation by promoting the expression of p21(Cip1/Waf1/Cid1), inhibitor of apoptosis protein 2 and B-cell lymphoma-2 but inhibiting the activity of Bad. Nuclear factor-kappaB and extracellular signal-regulated kinase 1/2 function upstream of haem oxygenase-1. Therefore, haem oxygenase-1 is likely to be a potential target in the treatment of smoking-related lung cancer.

Oestrogen mediates the growth of human thyroid carcinoma cells via an oestrogen receptor-ERK pathway

OBJECTIVES

Although thyroid cancer occurs much more frequently in females, the role of sex hormones in thyroid carcinogenesis is unknown. In this study, it has been investigated how 17beta-oestradiol (E2) influenced proliferation and growth of thyroid cancer cells.

MATERIALS AND METHODS

Cell proliferation and its related molecules were examined in thyroid papillary carcinoma cells (KAT5), follicular thyroid carcinoma cells (FRO) and anaplastic carcinoma cells (ARO). Levels of oestrogen receptor (ER) alpha and beta were regulated by their agonists (PPT and DPN), antagonists and siRNA.

RESULTS

E2 promoted cell proliferation. Such an effect was positively related to ERalpha but negatively to ERbeta; PPT enhanced cell proliferation while DPN inhibited it. PPT increased Bcl-2 expression while DPN decreased it. DPN also elevated Bax expression. PPT elevated the level of phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2), suggesting a positive role of ERK1/2 in E2-induced cell proliferation. Knockdown of ERalpha significantly attenuated E2-mediated Bcl-2 and pERK1/2 expression. In contrast, knockdown of ERbeta markedly enhanced them.

CONCLUSIONS

Oestrogen stimulates proliferation of thyroid cancer cells, associated with increase in Bcl-2 and decrease in Bax levels in an ERK1/2-related pathway. Imbalance between ERalpha and ERbeta may contribute to thyroid carcinogenesis.

Calcium-mediated activation of PI3K and p53 leads to apoptosis in thyroid carcinoma cells

The molecular mechanism responsible for cadmium-induced cell death in thyroid cancer cells (FRO) is unknown. We demonstrated that apoptosis of FRO cells induced by cadmium was concentration and time dependent. Cadmium caused the rapid elevation of intracellular calcium and induced phosphorylation of Akt, p53, JNK, ERK and p38. Inhibition of PI3K/Akt attenuated the cadmium-induced apoptosis, but the inhibition of JNK inhibitor, ERK or p38 aggravated it, indicating that activation of PI3K/Akt was a pro-apoptosis signal in response to cadmium treatment, whereas the activation of stress-activated protein kinase JNK, ERK and p38 functioned as survival signals to counteract the cadmium-induced apoptosis. Buffering of the calcium response attenuated mitochondrial impairment, recovered the cadmium-activated Akt, p53, JNK, ERK and p38, and subsequently blocked the apoptosis. These results suggested that apoptosis induced by cadmium in FRO cells was initiated by the rapid elevation of intracellular calcium, followed by calcium-mediated activation of PI3K/Akt and mitochondrial impairment.

Single nucleotide polymorphism in the promoter region of human alpha-fetoprotein (AFP) gene and its significance in hepatocellular carcinoma (HCC)

BACKGROUND

Variations of serum AFP levels in HCC patients and cell lines are likely due to the differential activity of enhancer/silencer elements that control AFP. To understand the potential mechanism underlying the differential expression of AFP, we have examined the sequence of the AFP promoter in HCC.

METHODS

Direct DNA sequencing was carried out to sequence 980 bp of AFP promoter of DNA samples isolated from 83 HCC patients.

RESULTS

Three novel SNPs in the promoter region of the AFP gene, which have not been previously reported, were found at positions -330, -401 and -692. The level of serum AFP was significantly higher in HCC patients with the CT genotype of 330 SNP or the AG genotype of the 401 SNP. The genotype of CG in 692 SNP was also associated with a significant elevated level of serum AFP, and further this genotype appeared to be associated with the high risk of HCC development. 401 SNP and 692 SNP were located at the positions of known binding sites for transcription factors that have a role in the production of AFP and the growth of tumors.

CONCLUSIONS

The novel polymorphisms identified in the promoter region of the AFP gene may be pathologically significant in HCC.

Increased expression of nucleophosmin/B23 in hepatocellular carcinoma and correlation with clinicopathological parameters

Nucleophosmin (NPM, B23, numatrin, NO38) is an abundant nucleolar phosphoprotein involved in multiple cellular functions. Previous evidence indicates that high-level expression of NPM causes uncontrolled cell growth and suggests that NPM may have oncogenic potential. In this study, we examined NPM expression in 103 paired cases of hepatocellular carcinoma (HCC), 12 cases of hepatic focal nodular hyperplasia, 17 cases of liver tissue adjacent to a hepatic haemangioma, and series of array tissues from normal human organs and malignancies using a monoclonal antibody against NPM and reverse transcription-PCR techniques, Western blot analysis, immunohistochemistry, and immunocytofluorescence. Our data indicated that NPM expression was significantly higher in HCC than in the non-malignant hepatocytes (P<0.001). Nucleophosmin was weakly expressed in hepatocytes from a 5-month-old embryo and in stationary hepatocytes of healthy adults. Moreover, enhanced expression of NPM in HCC correlated with the level of PCNA (R(2)=0.5639) and with the clinical prognostic parameters such as serum alpha fetal protein level, tumour pathological grading, and liver cirrhosis (P<0.05). Our results suggest that NPM may play an important role in the progression of tumorigenesis and that NPM may serve as a potential marker for HCC.

Migration of bone marrow stem cells in ischaemic brain

Stem cell therapy has been demonstrated to be effective in the management of haematological malignancy and solid cancer, but its role in neurodegenerative conditions remains uncertain. We hypothesize that: (1) ventricular delivery of bone marrow stem cells improves functional outcome in experimental ischaemia of the mouse brain; and (2) this improved outcome is due to migration of bone marrow stem cells to areas of ischaemia. Twelve mice with transient cerebral hemisphere ischaemia were randomly allocated to receive bone marrow stem cells or saline. The six animals that underwent cell therapy were found to perform better and committed fewer errors in the water maze system compared with the six control mice. Migration of these bone marrow stem cells was evident within the ventricular cerebro-spinal fluid (CSF) system and the brain parenchyma. This could also occur in clusters of cells. Preferential migration of these cells took place in lesioned areas.

Shear force induced monodisperse droplet formation in a microfluidic device by controlling wetting properties

Perpendicular flow is used to induce oil droplet breakup by using a capillary as water phase flow channel. It is a new route to produce monodisperse emulsions. The wetting properties of the fluids on the walls are exceedingly important parameters. Depending on the oil and water flow rates, different spatial distributions of the two phases as laminar, plugs, cobbles and drops, are obtained. The effects of two-phase flow rates on plugs and drop size are studied, and the different droplet formation mechanisms of plug flow and drop flow are discussed. Two quantitative equations utilized to predict the droplet size are developed.

Identification of hepatitis B virus X gene mutation in Hong Kong patients with hepatocellular carcinoma

BACKGROUND

Chronic infection by hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC) in man. The viral transactivator HBV X (HBx) gene plays a critical role in the molecular pathogenesis of HBV-related HCC.

OBJECTIVES

The aim of this study was to investigate whether there were particular HBx mutations associated with the Chinese Hong Kong patients with HCC.

STUDY DESIGN

We have examined HBx in 113 tumor tissue samples from patients with HCC and 48 serum samples from the same group. In addition, we also examined the expression of HBx protein and the index of apoptotic cell death in tumor tissues of HCC. The entire coding region of HBx gene from the sample was sequenced and aligned with the published HBx gene sequence.

RESULTS AND CONCLUSIONS

We have identified total 54 different types of mutations in HBx gene. HBx mutations occurred in a very high percentage of samples tested. Mutation of HBx was found in 95.2% and 95.3% of the tumor tissue and serum samples, respectively. Most of samples contained more than one type of the mutation. Relative risk analysis indicated that the mutations in 12 sites of tissue HBx and nine sites of serum HBx were highly associated with HCC, suggesting a potential role of these mutants in carcinogenesis. An insert mutation at position 204: Insert 204AGGCCC, was always found to co-exist with point mutations at 260 (G-->A) and 264 (G/C/T-->A). Furthermore, this particular pattern of HBx mutation was most frequently detected. Immunochemical staining of HBx protein revealed that the nuclear localization of HBx protein in hepatocytes of tumor tissues was highly associated with this particular pattern of HBx mutation. In conclusion, HBx mutation occurs frequently in HCC samples tested and a sample usually has multiple types of mutations. A special pattern of insert at 204 and point mutations at 260 and 264 was identified, and it appears to be associated with the nuclear localization of HBx protein. The development of multiple types of mutations in a given sample may contribute to the process of multiple steps in hepatocarcinogenesis.

Pharmacokinetics of Astragaloside IV in rats by liquid chromatography coupled with tandem mass spectrometry

Pharmacokinetics of Astragaloside IV (AGS-IV) in rats was studied by high performance liquid chromatography coupled with tandem mass spectrometry. The concentration in plasma was determined after i.v. administration of 1, 2, 4 mg/kg and p.o. administration of 20 mg/kg of AGS-IV. The AUC were linearly correlated to doses. Recoveries of AGS-IV in bile, urine and feces were also analyzed following i.v. dose of 2 mg/kg. Cumulative recovery of AGS-IV in bile reached 30.8% in 24h. Cumulative recovery of AGS-IV in urine and feces was 52.14%, which indicates that about 50% of AGS-IV was metabolized in vivo. The bioavailability of AGS-IV after p.o. administration was found to be 3.66%. These findings provide useful information for the research and development of AGS-IV and other potential agents.