Guided isolation of secondary metabolites from Nectria sp. MHHJ-3 by molecular network strategy.

The fungus Nectria sp. MHHJ-3 was isolated from Illigera rhodantha. A molecular networking-guided the secondary metabolites investigation of Nectria sp. MHHJ-3 led to the isolation of ten metabolites (1-10), including two new naphthalenone derivatives, nectrianaphthalenones A (1) and B (2), and two new steroids, nectriasteroids A (3) and B (4). Their structures were elucidated by extensive spectroscopic analysis including the HRESIMS, 1D/2D NMR and electronic circular dichroism (ECD) spectra. A plausible biosynthetic pathway for 1-2 was proposed. Compounds 1 and 2 exhibited moderate acetylcholinesterase (AChE) inhibitory activities. Compounds 3 and 4 showed significant cytotoxic activity against selected tumor cells. Particularly, compound 3 exhibited the strongest activity against A549 cells with an IC50 value of 13.73 ± 0.03 µM, which was at the same grade with that of positive control cisplatin.

Serum 25-hydroxyvitamin D levels and the risk of idiopathic central precocious puberty in girls.

INTRODUCTION: Prior studies have found inconsistent results regarding the relationship between vitamin D status and Idiopathic Central Precocious Puberty (ICPP). OBJECTIVE: To assess the role of serum 25-hydroxyvitamin D (25 [OH]D) levels in ICPP development. METHOD: The authors retrospectively collected data from 221 girls with ICPP and 144 healthy girls between January 2017 and December 2019. The participants' serum 25(OH)D levels were measured using an automatic chemiluminescence method, and the association between serum 25(OH)D levels and the risk of ICPP was assessed using multivariate logistic regression analysis. Odds Ratios (OR) with 95% Confidence Intervals (95% CI) were calculated as effect estimates. RESULTS: Serum 25(OH)D levels in the ICPP group were significantly lower than those in healthy controls (p < 0.001). Multivariate analysis indicated that girls with insufficient vitamin D levels (OR = 0.201; 95% CI 0.094-0.428; p < 0.001) and sufficient vitamin D levels (OR = 0.141; 95% CI 0.053-0.375; p < 0.001) both had a lower risk of ICPP than girls with vitamin D deficiency. Moreover, the authors found that the height (p = 0.014), weight (p = 0.014), breast stage (p = 0.010), mother's height (p < 0.001), and luteinizing hormone/follicle-stimulating hormone ratio (p = 0.010) in girls with ICPP could be associated with levels of vitamin D. CONCLUSION: This study found that a low serum 25(OH)D level is an independent risk factor for ICPP, and several characteristics of girls with ICPP could be affected by their vitamin D status.

NUCKS1 promotes the progression of colorectal cancer via activating PI3K/AKT/mTOR signaling pathway.

Nuclear ubiquitous casein and cyclin-dependent kinase substrate 1 (NUCKS1) is highly expressed in a variety of malignant tumors and functions as an oncogene; however, its role in colorectal cancer (CRC) remains unclear. We aimed to explore the function and regulatory mechanisms of NUCKS1 and potential therapeutic agents targeting NUCKS1 in CRC. We knocked down and overexpressed NUCKS1 in CRC cells and explored its effects in vitro and in vivo. Flow cytometry, CCK-8, Western blotting, colony formation, immunohistochemistry, in vivo tumorigenic, and transmission electron microscopy analyses were performed to determine the effects of NUCKS1 on CRC cell function. LY294002 was used to examine the mechanism of NUCKS1 expression in CRC cells. Potential therapeutic agents for NUCKS1-high CRC patients were analyzed using the CTRP and PRISM datasets, and the function of selected agents was determined by CCK-8 and Western blotting. We revealed that NUCKS1 was highly expressed in CRC tissues and clinically correlated with poor prognosis in CRC patients. NUCKS1 knockdown induces cell cycle arrest, inhibits CRC cell proliferation, and promotes apoptosis and autophagy. These results were reversed when NUCKS1 was overexpressed. Mechanistically, NUCKS1 exerts a cancer-promoting function by activating the PI3K/AKT/mTOR signaling pathway. This was reversed when LY294002 was used to inhibit the PI3K/AKT pathway. Furthermore, we determined that mitoxantrone exhibited high drug sensitivity in NUCKS1-overexpressing CRC cells. This work demonstrated NUCKS1 plays a crucial role in CRC progression via the PI3K/AKT/mTOR signaling pathway. Additionally, mitoxantrone may be a potential therapeutic agent for CRC treatment. Therefore, NUCKS1 represents a promising anti-tumor therapeutic target.

Steroids and dihydroisocoumarin glycosides from Xylaria sp. by the one strain many compounds strategy and their bioactivities.

The fungus Xylaria sp. KYJ-15 was isolated from Illigera celebica. Based on the one strain many compounds (OSMAC) strategy, the strain was fermented on potato and rice solid media, respectively. As a result, two novel steroids, xylarsteroids A (1) and B (2), which are the first examples of C28-steroid with an unusual ß- and γ-lactone ring, respectively, along with two new dihydroisocoumarin glycosides, xylarglycosides A (3) and B (4), were identified. Their structures were elucidated by spectroscopic methods, X-ray diffraction and electronic circular dichroism (ECD) experiments. All isolated compounds were evaluated for cytotoxicity, DPPH radical scavenging activity, acetylcholinesterase inhibitory and antimicrobial effect. Compound 1 exhibited potent AChE inhibitory activity with an IC50 value of 2.61 ± 0.05 µmol·L-1. The ß-lactone ring unit of 1 is critical for its AChE inhibitory activity. The finding was further confirmed through exploring the interaction of 1 with AChE by molecular docking. In addition, both compounds 1 and 2 exhibited obvious antibacterial activity against Bacillus subtilis with a minimum inhibitory concentration (MIC) of 2 µg·mL-1. Compounds 3 and 4 exhibited antibacterial activities against Staphylococcus aureus with MICs of 4 and 2 µg·mL-1, respectively, which also exhibited DPPH radical scavenging activity comparable to the positive control with IC50 values of 9.2 ± 0.03 and 13.3 ± 0.01 µmol·L-1, respectively.

Phytotoxic meroterpenoids with herbicidal activities from the phytopathogenic fungus Pseudopestalotiopsis theae.

The fungus Pseudopestalotiopsis theae isolated from the fresh leaves of Illigera celebica, has been reported to be a pathogenic fungus that can cause gray blight on tea leaves, a disease characterized by the appearance of necrotic lesions on tea leaves. The pathogenic substances in this fungus have not been clearly identified. Considering the possible involvement of specialized metabolites in symptom appearance, a chemical investigation of specialized metabolites on P. theae was conducted, resulting in the isolation of eight meroterpenoids, including six undescribed biscognienynes G-L and two known ones (biscognienynes B and D). The structures of these new compounds were characterized by extensive NMR spectroscopic and HR-ESI-MS data, and their absolute configurations were elucidated by ECD calculations. Except for biscogniyne L, all the isolated biscognienynes showed different degrees of phytotoxicity to tea in vivo, thereby revealing for the first time the substances in P. theae that cause tea gray blight. Inspired by the fact that phytotoxins produced by pathogenic fungus are an effective resource for designing natural and safe bioherbicides, when assayed the herbicidal activity through Petri dish bioassays, biscognienynes G-J showed phytotoxic effects against seed germination and seedling growth of Setaria viridis, strongly inhibiting seed germination percentage and radicle and germ lengths of seedlings. The results of this study demonstrated the great potential of biscognienynes G-J to be proposed and developed as ecofriendly herbicides.

A new cyclopentenone derivative from Trichoderma atroviride HH-01.

A new cyclopentenone derivative, atrovinol (1), together with ten known compounds (2-11) were isolated from Trichoderma atroviride HH-01, an endophytic fungus from Illigera rhodantha (Hernandiaceae). Their structures were identified by HRESIMS, 1 D/2D NMR, and electronic circular dichroism (ECD) spectra. Compound 1 exhibited moderate inhibitory activity against Staphylococcus aureus and Bacillus subtilis with MIC values of 8.0 µg/mL and 16.0 µg/mL, respectively.

Serum 25-hydroxyvitamin D levels and the risk of idiopathic central precocious puberty in girls

Abstract Introduction Prior studies have found inconsistent results regarding the relationship between vitamin D status and Idiopathic Central Precocious Puberty (ICPP). Objective To assess the role of serum 25-hydroxyvitamin D (25 [OH]D) levels in ICPP development. Method The authors retrospectively collected data from 221 girls with ICPP and 144 healthy girls between January 2017 and December 2019. The participants' serum 25(OH)D levels were measured using an automatic chemiluminescence method, and the association between serum 25(OH)D levels and the risk of ICPP was assessed using multivariate logistic regression analysis. Odds Ratios (OR) with 95% Confidence Intervals (95% CI) were calculated as effect estimates. Results Serum 25(OH)D levels in the ICPP group were significantly lower than those in healthy controls (p < 0.001). Multivariate analysis indicated that girls with insufficient vitamin D levels (OR = 0.201; 95% CI 0.094-0.428; p < 0.001) and sufficient vitamin D levels (OR = 0.141; 95% CI 0.053-0.375; p < 0.001) both had a lower risk of ICPP than girls with vitamin D deficiency. Moreover, the authors found that the height (p = 0.014), weight (p = 0.014), breast stage (p = 0.010), mother's height (p < 0.001), and luteinizing hormone/follicle-stimulating hormone ratio (p = 0.010) in girls with ICPP could be associated with levels of vitamin D. Conclusion This study found that a low serum 25(OH)D level is an independent risk factor for ICPP, and several characteristics of girls with ICPP could be affected by their vitamin D status.

A New Highly Oxygenated Polyketide Derivative from Trichoderma sp. and Its Antifungal Activity.

A new highly oxygenated polyketide derivative, trichodersine (1), together with fourteen known compounds (2-15) were isolated from Trichoderma sp. MWTGP-04. The structure of trichodersine (1) was established based on comprehensive spectroscopic data analysis, and biogenesis argument. The results of double culture experiments indicated that the strain exhibited potential antifungal activity. The antifungal activities of all isolated compounds were evaluated, among them compound 1 exhibited remarkable antifungal activities against Fusarium solani, Plectosphaerella cucumerina, Alternaria panax, and Aspergillus niger, with minimum inhibitory concentrations (MICs) of 4, 4, 16, and 32 µg/mL, respectively. In addition, the antifungal experiments of polyketide derivatives (1-3) disclosed that their degree of oxidation was a key factor affecting the antifungal activity.

A new cyclohexenone derivative from phomopsis sp. XM-01.

A new cyclohexenone derivative, phomopine (1), together with five known compounds (2-6) were isolated from Phomopsis sp. XM-01. The structure of 1 was determined by extensive spectroscopic analyses and electronic circular dichroism (ECD) calculation. In vitro bioassays, compounds 1 and 2 exhibited potent antimicrobial activities against Candida albicans and Staphylococcus aureus with their corresponding minimum inhibitory concentrations (MICs) of 64 µg/mL and 16 µg/mL, respectively.

Investigations of specialised metabolites of endophyte Diaporthe destruens hosted in Illigera orbiculata C. Y. Wu.

A chemical investigation of the endophytic fungus Diaporthe destruens from the Hernandiaceae plant Illigera orbiculata C. Y. Wu collected from southern Yunnan Province, China, led to the isolation of six undescribed compounds, including two azaphilone analogs, which are a pair of epimers (13R-hydroxy-chermesinone A and 13S-hydroxy-chermesinone A); a pyrrole derivative (1-(4-(methoxymethyl)-1H-pyrrol-3-yl)ethan-1-one); an isoindolone derivative (4-hydroxy-6-methoxyisoindolin-1-one); a benzylbenzene derivative (destruensine A) and a conjectural fragment of polyketide ((2R,4R)-2-(methoxymethyl)pentane-1,4-diol) along with nine known compounds. Their structures were elucidated by spectroscopic methods and HRESIMS, and the absolute configurations were further confirmed by electronic circular dichroism (ECD) and chemical derivatization. The antimicrobial activities, anti-acetylcholinesterase activities, antiproliferation, and NO production inhibitory effects of compounds 1-15 were evaluated.

Secondary Metabolites from Annulohypoxylon sp. and Structural Revision of Emericellins A and B.

Seven previously undescribed compounds were isolated from the endophytic fungus Annulohypoxylon sp. KYG-19 (family Xylariaceae), including three gymnomitrane-type sesquiterpenes xylariacinols A, B, and D (1, 2, and 4), one bisabolane-type sesquiterpene annulnol F (6), one phenol derivative lariacinol G (7), and two polyhydroxy compounds hypoxylonols H and I (8 and 9), together with two known gymnomitrane-type sesquiterpenes emericellin A (3) and 3-gymnomitren-15-ol (5). The assignments of their structures was determined by extensive spectroscopic and spectrometric analysis, acetonide analysis, Mosher's method, and X-ray crystallography. In addition, the structures of emericellins A and B, which were reported to possess an unprecedented tricyclo[4, 4, 2, 1]hendecane scaffold, were revised by comparing their spectroscopic data with those of 1 and 3. Compounds 1 and 4 exhibited antibacterial activity against Escherichia coli with minimum inhibitory concentrations of 4 and 2 µg/mL, respectively.

Clinical Observations of Kümmell Disease Treatment Through Percutaneous Fixation Combined with Vertebroplasty.

OBJECTIVE: To explore the safety and efficacy of percutaneous pedicle screw fixation combined with vertebroplasty for the treatment of stage III Kümmell disease. METHODS: The clinical data and follow-up results of 22 patients with Kümmell disease who were admitted to our department from 2014 to 2018 were analyzed. There were 14 females and eight males, and the Age range was 58-81 years. All patients were followed up for 24 months. The treatment method was percutaneous pedicle screw fixation combined with vertebroplasty. The patient general information such as age, gender, bedrest time and location of fracture vertebrae were recorded. The clinical symptoms and imaging data of visual analogue scale (VAS), bone cement leakage, Oswestry Disability Index (ODI), Cobb angle, anterior, middle and posterior height of the diseased vertebral body, and complications were recorded before operation and during follow-up. RESULTS: For patients enrolled, no bone cement leakage was observed during the operation; no patients developed infections after operation. The operation was safe and resulted in a short bedrest time. The VAS score and ODI index at 3 and 24 months postoperative (2.86 ± 0.83, 31.68% ± 6.21%; 3.0 ± 0.82, 32.78% ± 6.05%) were significantly lower than that recoded preoperatively (7.59 ± 0.59, 71.5% ± 8.84%) (P < 0.05). Additionally, there was no significant difference between the records at 3 and 24 months after operation (P > 0.05). Imaging data showed that the bone cement and screws were in good position and did not move during postoperative and follow-up. The anterior, middle and posterior height of the diseased vertebral body measured 2 days after surgery (23.46 ± 4.72, 23.12 ± 3.05, 25.81 ± 2.22) and at last follow-up (20.83 ± 4.48, 21.78 ± 2.74, 24.74 ± 1.93) were higher than that recorded preoperatively (13.08 ± 4.49, 12.93 ± 3.53, 19.32 ± 2.73) (P < 0.05), and the Cobb angle measured 2 days and 24 months after operation (9.57 ± 4.63, 10.68 ± 3.97) were lower than that recorded preoperatively (28.24 ± 8.95) (P < 0.05), and no significant difference was found between the values recorded at 2 days and 24 months after operation (P > 0.05). Follow-up for 24 months, there was no re-fracture of the diseased vertebrae and internal fixation loosening, but two cases of adjacent vertebral refracture complications occurred, and the effect was good after PVP treatment. CONCLUSION: Short-segment percutaneous pedicle screw fixation combined with vertebroplasty in the treatment of stage III Kümmel disease can effectively restore the height of the diseased vertebrae, kyphosis correction, reduce trauma, prevent the diseased vertebral body from collapsing again, and effectively improves clinical symptoms.

KISS1/KISS1R mediates Sertoli cell apoptosis via the PI3K/AKT signalling pathway in a high­glucose environment.

In male patients with diabetes, reduced sperm motility and fertility are observed. KiSS­1 metastasis suppressor (KISS1)/KISS1 receptor (KISS1R) serves an important role in regulating adolescent sexual maturity and reproductive system development in mammals; however, the mechanism underlying KISS1/KISS1R in reproductive dysfunction in male patients with diabetes is not completely understood. The aim of the present study was to examine the role of KISS1/KISS1R in Sertoli cells. High glucose (HG)­induced mouse Sertoli cells were used to model diabetes in vitro. KISS1/KISS1R overexpression and knockdown were established in mouse Sertoli cells. Reverse transcription­quantitative PCR and western blotting were performed to measure the expression levels of KISS1/KISS1R and apoptosis­related proteins. Cell viability and apoptosis was assessed by performing Cell Counting Kit­8, TUNEL staining and flow cytometry assays, respectively. Western blotting was performed to assess the expression levels of PI3K/AKT signalling­related proteins. KISS1/KISS1R expression levels were downregulated in HG­induced mouse Sertoli cells compared with control cells. KISS1/KISS1R overexpression significantly suppressed HG­induced apoptosis and decrease of viability in mouse Sertoli cells. Moreover, the western blotting results indicated that KISS1/KISS1R activated PI3K/AKT signalling. Treatment with PI3K/AKT pathway inhibitor significantly reversed KISS1/KISS1R­mediated protective effects. Collectively, the results of the present study suggested that KISS1/KISS1R mediated Sertoli cell apoptosis via the PI3K/AKT signalling pathway under HG conditions, which provided reliable targets for the treatment of reproductive dysfunction in male patients with diabetes.

(-)-Grandiflorimine, a new dibenzopyrrocoline alkaloid with cholinesterase inhibitory activity from Illigera grandiflora.

A new dibenzopyrrocoline alkaloid, (-)-grandifloramine (1), together with five known ones, actinodaphnine (2), N-methyllaurotetanine (3), boldine (4), lindcarpine (5), and (+)-norboldine (6), were isolated from Illigera grandiflora W. W. Sm. et J. F. Jeff. The structure of 1 was identified by HRESIMS, 1D/2D NMR, and electronic circular dichroism (ECD) spectra. Compound 1 and 2 exhibited the moderate inhibitory activity against acetylcholinesterase and 3 showed moderate butyrylcholinesterase inhibitory activity. This is the first report of the chemical constituents of I. grandiflora.

Assessment of kitchen emissions using a backpropagation neural network model based on urinary hydroxy polycyclic aromatic hydrocarbons.

Kitchen emissions are mixed indoor air pollutants with adverse health effects, but the large-scale assessment is limited by costly equipment and survey methods. This study aimed to discuss the application of backpropagation (BP) neural network models in the assessment of kitchen emissions based on the exposure marker. A total of 3686 participants were recruited for the kitchen survey, and their sleep quality was measured by the Pittsburgh sleep quality index (PSQI). After excluding the confounders, 365 participants were selected to assess their urinary hydroxy polycyclic aromatic hydrocarbons (OH-PAHs) concentrations by ultra-high-performance liquid chromatography/tandem mass spectrometry. Two BP neural network models were then set up using the survey and detection data from the 365 participants and used to predict the total urinary OH-PAHs concentrations of all participants. The total urinary OH-PAHs and 1-hydroxy-naphthalene (1-OHNap) concentrations were significantly higher among the 365 participants with poor sleep quality (global PSQI score > 5; P < 0.05). Results from internal and external validation showed that our model has high credibility (model 2). Further, the participants with higher predicted total urinary OH-PAHs concentrations were associated with the global PSQI score of >5 (odds ratio (OR) = 1.284, 95% confidence interval (CI) = 1.082-1.525 for participants with predicted total urinary OH-PAHs concentrations of over 1.897 µg/mmol creatinine in model 1, and OR = 1.467, 95% CI = 1.240-1.735 for participants with predicted total urinary OH-PAHs concentrations of over 2.253 µg/mmol creatinine in model 2) after adjusting for the confounders. Findings suggest that the BP neural network model is suitable for assessing kitchen emissions, and the urinary OH-PAHs concentrations can be taken as the model outlay.

Lung Cancer Cells-Controlled Dkk-1 Production in Brain Metastatic Cascade Drive Microglia to Acquire a Pro-tumorigenic Phenotype.

OBJECTIVES: Organotropism is primarily determined by tumor-derived exosomes. To date, the role of lung cancer cells-derived exosomes underlying the pre-metastatic niche formation is unclear. MATERIALS AND METHODS: The animal models of retro-orbital and intra-ventricular injection were constructed to administrate lung cancer cells-derived exosomes. Cytokine array was used to screen the cytokines released from brain endothelium after internalization of lung cancer cells-derived exosomes. The cellular co-culture system was established to mimic microglia-vascular niche contained lung cancer cells-derived exosomes. The levels of Dkk-1 and the activities of microglia were analyzed by qRT-PCR, western blot and immunofluorescence. In vivo selections of highly brain metastatic cells were performed to analyze the direct interaction of lung cancer cells with microglia. RESULTS: Animal studies demonstrated that there was a suppressive signal transferred from brain endothelium to microglia after internalization of lung cancer cells-derived exosomes into brain endothelium, which caused an absolutely less M1 phenotypic microglia and a relatively more M2 phenotypic microglia. Further results indicated that lung cancer cells-derived exosomes induced a release of endogenous Dkk-1 from brain endothelium, which rendered microglia to acquire a pro-tumorigenic feature in pre-metastatic niche. Subsequently, the declines of Dkk-1 in metastatic lung cancer cells removed the suppression on microglia and enhanced microglial activation in metastatic niche. CONCLUSION: Our findings shed a new light on the synergistic reaction of the different cells in "neurovascular units" toward the metastatic messages from lung cancer cells and provided a potential therapeutic pathway for lung cancer metastasis to brain.

Manganese modifies Neurotrophin-3 (NT3) and its tropomyosin receptor kinase C (TrkC) in the cortex: Implications for manganese-induced neurotoxicity.

Manganese (Mn), an essential micronutrient, has the potential to induce apoptosis. The NT3/TrkC ligand/receptor pair known as part of the classic neurotrophic theory plays a critical role in neuronal survival. However, whether the NT3/TrkC-mediated signaling pathways are involved in Mn-induced apoptosis of cortical neurons remains unknown. The present study was designed to investigate the interactions between NT3/TrkC-mediated signaling pathways and Mn-induced apoptosis in cortical neurons. This study showed that subacute Mn exposure significantly increased the levels of pro-apoptotic Bax while decreasing the levels of anti-apoptotic Bcl 2 in the cortex compared with the corresponding control. Markedly reduced NT3 and TrkC levels along with decreased Ras/MAPK and PI3/Akt signaling in the cortex were observed following subacute Mn exposure. We further found increased levels of Bax, cleaved caspase-3, and the total apoptosis rate, and decreased levels of Bcl 2, NT3, TrkC, and Ras/MAPK and PI3/Akt signaling in Mn-treated primary cortical neurons. Pretreatment with hNT3 or Z-VAD-FAM ameliorated Mn-induced apoptosis by increasing the levels of NT3 and TrkC and its Ras/MAPK and PI3/Akt signaling pathways. Taken together, our findings clearly indicate that NT3/TrkC and mediated Ras/MAPK and PI3/Akt signaling pathways play a crucial role in Mn-induced neurotoxicity.

[Effect of Baicalin Derivative 02-036 on Burkitt Lymphoma Cell Line CA46 and Its Related Mechanisms].

OBJECTIVE: To investigate the effect of baicalin derivative 02-036 on proliferation and apoptosis human Burkitt lymphoma cell line CA46 and its related mechanisms. METHODS: The MTT assay and cell colony formation assay were used to measure the growth inhibition of CA46 cells after 02-036 treatment. The flow cytometry with AnnexinV-FITC/PI double staining was employed to detect the apoptosis induction effect of 02-036 on CA46 cells. Cell cycle distribution of CA46 cells was estimeted by using DNA ploid analysis. Western blot was used to determine the changes of apoptosis-related proteins, including C-MYC, BCL-2, Procaspase-9, Procaspase-3, PARP and Cleaved-PARP. RESULTS: Baicalin derivative 02-036 obviously inhibited the proliferation of CA46 cells, with dose- and time-dependent manner (r=0.963, r=0.992). The averaged IC50 value of CA46 cells was (6.04±0.11) µmol/L after 48-hour treatment. Low concentration of 02-036 could significantly inhibit the colony formation of CA46 cells. Flow cytometry analysis confirmed that 02-036 could effectively induce CA46 cell apoptosis. The apoptosis rate correlated with drug concentrations (r=0.959). Also, DNA ploid analysis showed that the cell cycle of CA46 was arrested in the S phase. The expression levels of BCL-2, Pro-caspase-9, Pro-caspase-3, PARP and C-MYC proteins decreased with a 02-036-dose dependent manner (r values were -0.990, -0.939, -0.971 and -0.967, respectively). In contrast, the expression level of cleaved-PARP increased with the same manner (r=0.920). CONCLUSION: Baicalin derivative 02-036 can effectively inhibit the proliferation and induce apoptosis of CA46 cells, and its related mechanisms may be correlated with the down-regulation of apoptosis-related molecule expression levels, such as BCL-2, Pro-caspase-9, Pro-caspase-3, PARP and C-MYC.

[Inhibitory Effect of NPM Gene Knockdown on Proliferation of Chronic Myeloid Leukemia Cell Line K562 and Its Mechanism].

OBJECTIVE: To investigate the role of nucleophosmin (NPM) in the proliferation of chronic myeloid leukemia cells (K562 cells) and its mechanism by RNAi technology. METHODS: shRNA was used to inhibit the expression of NPM. The expression of NPM gene was detected by real-time quantitative PCR. The effect of inhibiting NPM gene on cell proliferation was detected by MTS assay. Change of cell cycle was detected by flow cytometry. Western blot was used to detect the expression of cell cycle-related proteins. RESULTS: The shRNA lentiviral vector targeting at NPM gene was successfully constructed and used to transfect the K562 cells. The results showed that compared with the control groups, suppression of NPM gene expression in K562 cells could inhibit the cell proliferation and decrease the cell colony formation. Moreover, interference of NPM gene could prolong G0/G1 phase and arrest cell cycle, which may be related to the down-regulation of NPM gene expression and activation of p21 protein expression, thereby inhibited the formation of CDK2/ Cyclin E complex. CONCLUSION: Down-regulation of NPM gene expression in K562 cells can induce cell cycle arrest and inhibit cell proliferation.