Inhibition of Cyclin F Promotes Cellular Senescence through Cyclin-dependent Kinase 1-mediated Cell Cycle Regulation

Objective Kidney renal clear cell carcinoma(KIRC)is a common renal malignancy that has a poor prognosis.As a member of the F box family,cyclin F(CCNF)plays an important regulatory role in normal tissues and tumors.However,the underlying mechanism by which CCNF promotes KIRC proliferation still remains unclear.Methods Bioinformatics methods were used to analyze The Cancer Genome Atlas(TCGA)database to obtain gene expression and clinical prognosis data.The CCK8 assay,EdU assay,and xenograft assay were used to detect cell proliferation.The cell senescence and potential mechanism were assessed by SA-β-gal staining,Western blotting,as well as ELISA.Results Our data showed that CCNF was highly expressed in KIRC patients.Meanwhile,downregulation of CCNF inhibited cell proliferation in vivo and in vitro.Further studies showed that the reduction of CCNF promoted cell senescence by decreasing cyclin-dependent kinase 1(CDK1),increasing the proinflammatory factors interleukin(IL)-6 and IL-8,and then enhancing the expression of p21 and p53.Conclusion We propose that the high expression of CCNF in KIRC may play a key role in tumorigenesis by regulating cell senescence.Therefore,CCNF shows promise as a new biomarker to predict the clinical prognosis of KIRC patients and as an effective therapeutic target.

Cyclin-dependent kinase 5 is required for suppressing D1-dependent signaling mediated through muscarinic 4 in isolated medium spiny neurons

OBJECTIVE Previous studies have demonstrated acetylcholine muscarinic 4(M4) receptor regulates DARPP-32 phosphorylation at Thr75 in isolated medium spiny neurons(MSNs),indicating antagonistic mechanism with D1 dependent signal cascade,but the exact molecular mechanisms remain unclearly.In this study,we investigated the roles of M4 receptor in modulation D1 dependent signal to integrate striatal DA inputs in isolated MSNs.METHODS(1)Lentivirus technology was employed to genetically knock down the M4 receptor of MSNs;(2) Apomorphine(APO),acts as a dopamine receptor agonist,while SCH23390,acts as a selective antagonist for D1,were used to study the pharmacologically profiles with D1 receptor stimulation or blockade,respectively.Then the no subtype-selective muscarinic agonist oxotremorine M(OX) were used to show that mAchRs activation,in order to dissect the particular function of M4,a selective M4 antagonist,MT3 was used;(3) Intracellular cAMP production of MSNs was measured by using time resolved fluorescence resonance energy transfer detection method;(4) Laser confocal was used to explore the expression of M4 and D1 in MSNs;(5) Immunofluorescence cytochemistry and Western blotting were used to confirm the alteration of signaling molecular including P-CREB,DARPP-32 P-Thr34,DARPP-32 P-Thr75,cyclin-dependent kinase 5(CDK5) as wel as p25/35,which are involved in DA-dependent signaling modulations.RESULTS Firstly,TR-FRET assay revealed APO(10-2 mol·L^(-1))significantly increased the level of intracellular cAMP(vs control,n=3,P<0.01),also Western blotting results showed that APO(10-6 mol · L^(-1))increased DARPP-32 Thr34 phosphorylation(vs control,n=3,P<0.01),and these effect were reversed by D1 receptor antagonist SCH23390(vs APO,n=3,P<0.01).Interestingly,we confirmed that OX(10-6 mol · L^(-1)) down-regulated APO-induced DARPP-32 Thr34 phosphorylation(vs APO,n=3,P<0.01),due to its effects on DARPP-32 phosphorylation at Thr75.The results presented the antagonistic mechanism of mAchRs stimulation with D1 dependent signal cascade in MSNs.Meanwhile,OX(10-7,10-6 and10^(-5) mol·L^(-1)) stimulated DARPP-32 phosphorylation at Thr75,and simultaneously up regulated P25/35 and CDK5 activity(vs control,n=3,P<0.01) by using Western blotting assay.Furthermore,roscovitine(10^(-5) mol · L^(-1)),acts as a CDK5 inhibitor,suppressed CDK5 activity(vs control,n=10,P<0.01),and fully inhibited OX-induced DARPP-32 Thr75 phosphorylation(vs OX,n=10,P<0.01).More important,pretreated with roscovitine(10^(-5) mol·L^(-1)),the effect of APO on DARPP-32 Thr34 phosphorylation was potentiated(vs APO,n=3,P<0.05).The result presented CDK5 is required in suppression of APO on DARPP-32 Thr34 phosphorylation mediated through mAchRs stimulation.In addition,laser confocal results showed that the CDK5 up-regulation was mostly confined to MSNs co-expressing M4,which means that M4 participated in CDK5-mediated phosphorylation of DARPP-32 at Thr75.Consistently,immunofluorescence and Western blotting results confirmed that both genetic knockdown and pharmacologic inhibition of M4 receptors with MT3(10-7 mol · L^(-1)) down-regulated the OX-induced the expression of CDK5(vs OX,n=3,P<0.01) and P25/35(vs OX,n=3,P<0.01)in isolated MSNs.CONCLUSION M4 receptor may play an important role in antagonistic regulation D1 dependent signaling,in which CDK5 is required for suppressing D1-DARPP-32 Thr34 phosphorylation in isolated medium spiny neurons.

Molecular mechanism underlying the functional loss of cyclindependent kinase inhibitors p16 and p27 in hepatocellular carcinoma

Hepatocellular carcinoma （HCC） is one of the most common human cancers, and its incidence is still increasing in many countries. The prognosis of HCC patients remains poor, and identification of useful molecular prognostic markers is required. Many recent studies have shown that functional alterations of cellcycle regulators can be observed in HCC. Among the various types of cell-cycle regulators, p16 and p27 are frequently inactivated in HCC and are considered to be potent tumor suppressors, p16, a G1-specific cell-cycle inhibitor that prevents the association of cyclindependent kinase （CDK） 4 and CDK6 with cyclin DI, is frequently inactivated in HCC via CpG methylation of its promoter region, p16 may be involved in the early steps of hepatocarcinogenesis, since p16 gene methylation has been detected in subsets of pre-neoplastic liver cirrhosis patients, p27, a negative regulator of the G1-S phase transition through inhibition of the kinase activities of Cdk2/cyclin A and Cdk2/cyclin E complexes, is now considered to be an adverse prognostic factor in HCC. In some cases of HCC with increased cell proliferation, p27 is overexpressed but inactivated by sequestration into cyclin D1-CDK4-containing complexes. Since loss of p16 is closely related to functional inactivation of p27 in HCC, investigating both p16 and p27 may be useful for precise prognostic predictions in individuals with HCC.

Promoter methylation status of hMLH1,MGMT,and CDKN2A/p16 in colorectal adenomas

AIM:To investigate aberrant DNA methylation of CpG islands and subsequent low-or high-level DNA microsatellite instability(MSI)which is assumed to drive colon carcinogenesis. METHODS:DNA of healthy individuals,adenoma(tu-bular or villous/tubulovillous)patients,and colorectal carcinoma patients who underwent colonoscopy was used for assessing the prevalence of aberrant DNA methylation of human DNA mismatch repair gene mutator L homologue 1(hMLH1),Cyclin-dependent kinase inhibitor 2A(CDKN2A/p16),and O-6-methylguanine DNA methyltransferase(MGMT),as well as their rela- tion to MSI. RESULTS:The frequency of promoter methylation for each locus increased in the sequence healthy tissue/adenoma/carcinoma.MGMT showed the highest frequency in each group.MGMT and CDKN2A/p16 presented a statistically significant increase in promoter methylation between the less and more tumorigenic forms of colorectal adenomas(tubular vs tubullovillous and villous adenomas).All patients with tubulovillous/villous adenomas,as well as all colorectal cancer patients,showed promoter methylation in at least one of the examined loci.These findings suggest a potentially crucial role for methylation in the polyp/adenoma to cancer progres- sion in colorectal carcinogenesis.MSI and methylation seem to be interdependent,as simultaneous hMLH1, CDKN2A/p16,and MGMT promoter methylation was present in 8/9 colorectal cancer patients showing the MSI phenotype. CONCLUSION:Methylation analysis of hMLH1,CD- KN2A/p16,and MGMT revealed specific methylation profiles for tubular adenomas,tubulovillous/villous adenomas,and colorectal cancers,supporting the use of these alterations in assessment of colorectal tumorigenesis.

MiR-451 inhibits proliferation of esophageal carcinoma cellline EC9706 by targeting CDKN2D and MAP3K1

AIM To investigate the underlying molecularmechanisms of miR-451 to inhibit proliferation ofesophageal carcinoma cell line EC9706.METHODS： Assays for cell growth, apoptosis andinvasion were used to evaluate the effects of miR-451expression on EC cells. Luciferase reporter and Westernblot assays were used to test whether cyclin-dependentkinase inhibitor 2D （CDKN2D） and MAP3K1 act as majortargets of miR-451.RESULTS： The results showed that CDKN2D andMAP3K1 are direct targets of miR-451. CDKN2D andMAP3K1 overexpression reversed the effect of miR-451.MiR-451 inhibited the proliferation of EC9706 bytargeting CDKN2D and MAP3K1.CONCLUSION： These findings suggest that miR-451might be a novel prognostic biomarker and a potentialtarget for the treatment of esophageal squamous cellcarcinoma in the future.

Synergistic Effects of Targeting Survivin and CDK1 on Nasopharyngeal Carcinoma <i>in Vitro</i>and <i>in Vivo</i>

Background: To explore the impact of pU6-based tandem survivin and CDK1-specific short hairpin RNA on the biological behaviors of CNE-2 nasopharyngeal carcinoma cells in vitro and in vivo. Patients and Methods: The vectors of pU6-survivinshRNA, pU6-CDK1shRNA and pU6-survivinshRNA-CDK1shRNA were constructed and transfected into CNE-2 cells with Lipofectamine TM 2000, respectively. The mRNAs and proteins of CDK1 and survivin were determined by RT-PCR and Western blotting, accordingly. MTT assay was employed to evaluate the proliferation of CNE-2 cells, and flow cytometry was performed to determine the apoptosis of CNE-2 cells. The effects of interfering survivin and CDK1 on tumorigenesis were evaluated by tumor xenografts experiments. Results: Effective plasmids were successfully constructed knocking down survivin and/or CDK1. The proliferation inhibition of CNE-2 cells by pU6-survivinshRNA-CDK1shRNA (32.5%) was higher than that of by pU6-survivinshRNA (25.6%) and pU6-CDK1shRNA (15.6%), and apoptosis in CNE-2 cells simultaneously interfering survivin and CDK1 (15.2%) dramatically increased when compared to those of interfering survivin (5.4%) or CDK1 (4.7%) alone. Furthermore, simultaneously interfering survivin and CDK1 is more effective than interfering alone component in inhibiting tumor growth of fBalb/C nude mice xenografted with CNE-2 cells. Conclusion: The results altogether indicate that interfering survivin and CDK1simutaneously can produce synergistic effects of anti-nasopharyngeal carcinoma, which could be a potential therapeutic method.

EXPRESSION OF CYCLIN D1 AND CDK4 IN OSTEOSARCOMA OF THE JAWS

Objective: To analyze cyclin D1 and cyclin-dependent kinase 4 (CDK4) expression and their significance in osteosarcoma of the jaws. Methods: Immunohistochemical ABC method was used to detect the expression of cyclin D1 and CDK4 in 20 cases of osteosarcoma and 8 cases of osteochondroma of the jaws. Results: The positive rates of cyclin D1 and CDK4 were 65% (13/20) and 60% (12/20), respectively. There was significant positive correlation between cyclin D1 and CDK4 expression (γs=0.48, P<0.05). Both cyclin D1 and CDK4 were present in 1/8 (12.5%) osteochondroma. The positive rate was remarkably different between osteosarcoma and osteochondroma (P<0.05). Conclusion: Cyclin D1 and CDK4 are overexpressed in osteosarcoma of the jaws and closely related to its occurrence and development.

Correlation between the expression of CyclinB1/CDK1 complex in esophageal cancer tissue and the contents of marker molecules in serum and lesion

Objective: To study the correlation between the expression of CyclinB1/CDK1 complex in esophageal cancer tissue and the contents of marker molecules in serum and lesion. Methods:Patients who were diagnosed with esophageal cancer in Mianyang Central Hospital between April 2014 and December 2016 were selected as esophageal cancer group, and the esophageal cancer lesion tissue, adjacent lesion tissue and serum samples were collected;healthy volunteers who received physical examination during the same period were selected as control group and serum samples were collected. The expression of CyclinB1/CDK1 complex, tumor suppressor genes and invasion genes in esophageal cancer lesion tissue and adjacent lesion tissue as well as the levels of tumor markers in serum were detected. Results: CyclinB1, CDK1 and E2F-1 mRNA expression in esophageal cancer lesion were significantly higher than those in adjacent lesion;serum tumor markers CYFRA21-1, SCC-Ag, CD44v5 and Stathmin levels of esophageal cancer group were significantly higher than those of control group and positively correlated with CyclinB1, CDK1 and E2F-1 mRNA expression in esophageal cancer lesion, PTEN, Spink8, p21 and p18 mRNA expression in esophageal cancer lesion were significantly lower than those in adjacent lesion and negatively correlated with CyclinB1, CDK1 and E2F-1 mRNA expression in esophageal cancer lesion, and nestin, β-catenin, Snail and Vimentin mRNA expression in esophageal cancer lesion were significantly higher than those in adjacent lesion and positively correlated with CyclinB1, CDK1 and E2F-1 mRNA expression in esophageal cancer lesion. Conclusion: The high expression of CyclinB1/CDK1 complex in esophageal cancer tissue can promote the proliferation and invasion of cancer cells.

Effect of cis-9,trans-11-conjugated linoleic acid on cell cycle of gastric adenocarcinoma cell line(SGC-7901)

AIM: To determine the effect of cis -9, trans -11-conjugated linoleic acid (c9, t11-CLA) on the cell cycle of gastric cancer cells (SGC-7901) and its possible mechanism in inhibition cancer growth. METHODS: Using cell culture and immunocytochemical techniques, we examined the cell growth, DNA synthesis, expression of PCNA, cyclin A, B(1), D(1), p16(ink4a) and p21(cip/waf1) of SGC-7901 cells which were treated with various c9, t11-CLA concentrations (25, 50, 100 and 200 micromol.L(-1))of c 9, t 11-CLA for 24 and 48h, with a negative control (0.1% ethane). RESULTS: The cell growth and DNA synthesis of SGC-7901 cells were inhibited by c9, t11-CLA.SGC-7901 cells. Eight day after treatment with various concentrations of c9, t11-CLA mentioned above, the inhibition rates were 5.92%, 20.15%, 75.61% and 82.44%, respectively and inhibitory effect of c9, t11-CLA on DNA synthesis (except for 25 micromol.L, 24h) showed significantly less (3)H-TdR incorporation than that in the negative controls (P【0.05 and P【0.01). Immunocytochemical staining demonstrated that SGC-7901 cells preincubated in media supplemented with different c9, t11-CLA concentrations at various times significantly decreased the expressions of PCNA (the expression rates were 7.2-3.0%, 24h and 9.1-0.9% at 48h, respectively), Cyclin A (11.0-2.3%, 24h and 8.5-0.5%,48h), B(1) (4.8-1.8% at 24h and 5.5-0.6% at 48h)and D(1) (3.6-1.4% at 24h and 3.7%-0 at 48h) as compared with those in the negative controls(the expressions of PCNA, Cyclin A, B(1) and D(1) were 6.5% at 24h and 9.0% at 48h, 4.2% at 24h and 5.1% at 48h, 9.5% at 24h and 6.0% at 48h,respectively)(P【0.01), whereas the expressions of P16(ink4a) and P21(cip/waf1), cyclin-dependent kinases inhibitors(CDKI), were increased. CONCLUSION: The cell growth and proliferation of SGC-7901 cell is inhibited by c9, t11-CLA via blocking the cell cycle, with reduced expressions of cyclin A,B(1) and D(1) and enhanced expressions of CDKI(P16(ink4a) and p21(cip/waf1)).

Effects of histone acetylation and DNA methylation on p21^(WAF1)regulation

Cell cycle progression is regulated by interactions between cyclins and cyclin-dependent kinases (CDKs). p21(WAF1) is one of the CIP/KIP family which inhibits CDKs activity. Increased expression of p21(WAF1) may play an important role in the growth arrest induced in transformed cells. Although the stability of the p21( WAF1) mRNA could be altered by different signals, cell differentiation and numerous influencing factors. However, recent studies suggest that two known mechanisms of epigenesis, i.e.gene inactivation by methylation in promoter region and changes to an inactive chromatin by histone deacetylation, seem to be the best candidate mechanisms for inactivation of p21( WAF1). To date, almost no coding region p21(WAF1) mutations have been found in tumor cells, despite extensive screening of hundreds of various tumors. Hypermethylation of the p21(WAF1) promoter region may represent an alternative mechanism by which the p21(WAF1/CIP1) gene can be inactivated. The reduction of cellular DNMT protein levels also induces a corresponding rapid increase in the cell cycle regulator p21(WAF1) protein demonstrating a regulatory link between DNMT and p21(WAF1) which is independent of methylation of DNA. Both histone hyperacetylation and hypoacetylation appear to be important in the carcinoma process, and induction of the p21(WAF1) gene by histone hyperacetylation may be a mechanism by which dietary fiber prevents carcinogenesis. Here, we review the influence of histone acetylation and DNA methylation on p21(WAF1) transcription, and affection of pathways or factors associated such as p 53, E2A, Sp1 as well as several histone deacetylation inhibitors.

p21 and p27 immunoexpression in gastric well differentiated endocrine tumors(ECL-cell carcinoids)

AIM： To investigate the expression of cyclin-dependent kinase inhibitors p21 and p27 in gastric well differentiated endocrine tumors （GWDET） （ECLocell carcinoids）.METHODS： The expressions of p21 and p27 were examined immunhistochemically in endoscopic biopsy specimens from 16 patients matching the diagnostic criteria of GWDET. Percentage of positive nuclear staining either weak or strong was noted. The association of immunoexpressions with age, gender, tumor localization, multifocality and accompanying chronic atrophic gastritis, neuroendocrine cell hyperplasia （NEH）, neuroendocrine dysplasia （NED）, intestinal metaplasia （IM）, Ki-67 proliferation index and clinical outcome were also evaluated.RESULTS： All cases expressed p27 with a mean expression score of 43.6%, while 31.3% of the cases showed any p21 expression, p21 and p27 immunoexpressions were significantly correlated with each other （P 〈 0.01）, and the p21-expressing group had higher p27 expression scores （68% vs 22%）. p21 and p27 expressions were lower in women, in non-atrophic mucosa and cases whose tumors were located somewhere other than fundus without submucosal extension. On contrary, p21 and p27 expressions were higher in males and the patients with submucosal extension and atrophic gastritis. Cases presenting lower p27 scores had solitary tumors showing neither NEH-NED nor IM. Despite, cases with lower p21 expression presented multifocal tumors accompanied by NEH-NED. However, no correlation of p21 and p27 expressions was found with age and Ki-67 expression.CONCLUSION： p27 is widely expressed in GWDETs, while p21 expression is sparse and observed in two thirds of the cases. Loss of p21 and p27 expressions may be correlated with different carcinoid tumor subtypes; however,more studies are needed to assess the role of these prospective markers in gastrointestinal endocrine tumors.

Contragestazol (DL111-IT) inhibits proliferation of human androgen-independent prostate cancer cell line PC3 in vitro and in vivo

Aim： To evaluate the antiproliferative activity of contragestazol （DL111-IT） on the human prostate cancer cell line PC3 in vitro and in vivo and to elucidate its potential molecular mechanisms. Methods： The cell killing ability of DL111-IT was measured by the 3-（4,5-dimethylthia-zol,2-yl）-2,5-diphenyltetrazolium bromide （MTT） reagent assay method and the tumor xenograft model. The cell cycle was analyzed by flow cytometry and protein expression, including retinoblastoma （pRb）, cyclin-dependent kinase 4 （CDK4） and cyclin D 1, was detected by Western blotting. Results： DL111-IT exhibited high efficiency on cell growth inhibition of the human androgen-independent prostate cancer cell line PC3. The drug concentration that yielded 50 % cell inhibition （IC50 value） was 9.9 mg/mL. In the PC3 tumor xenograft study, DL111-IT （1.25 mg/kg-20.0 mg/kg） given once a day for 10 days significantly inhibited tumor growth, with the inhibition rate ranging from 21% to 50 %. Flow cytometric analysis indicated that DL111-IT could cause GI arrest in the PC3 cell line, but not apoptosis. DL111-IT enhanced pRb expression and down-regulated CDK4 and cyclin D 1 expression, suggesting that cell cycle regulation might contribute to the anticancer property of DL 111- IT. Conclusion： DL111-1T inhibits the proliferation of human androgen-independent prostate cancer cell line PC3 in vitro and in vivo by a cell cycle regulation pathway.

Cyclin-dependent kinase 7 inhibitor THZ1 in cancer therapy

Current cancer therapies have encountered adverse response due to poor therapeutic efficiency,severe side effects and acquired resistance to multiple drugs.Thus,there are urgent needs for finding new cancer-targeted pharmacological strategies.In this review,we summarized the current understanding with THZ1,a covalent inhibitor of cyclin-dependent kinase 7(CDK7),which demonstrated promising anti-tumor activity against different cancer types.By introducing the anti-tumor behaviors and the potential targets for different cancers,this review aims to provide more effective approaches to CDK7 inhibitor-based therapeutic agents and deeper insight into the diverse tumor proliferation mechanisms.

Cdk5 knocking out mediated by CRISPR-Cas9 genome editing for PD-L1 attenuation and enhanced antitumor immunity

Blocking the programmed death-ligand 1(PD-L1)on tumor cells with monoclonal antibody therapy has emerged as powerful weapon in cancer immunotherapy.However,only a minority of patients presented immune responses in clinical trials.To develop an alternative treatment method based on immune checkpoint blockade,we designed a novel and efficient CRISPR-Cas9 genome editing system delivered by cationic copolymer aPBAE to downregulate PD-L1 expression on tumor cells via specifically knocking out Cyclin-dependent kinase 5(Cdk5)gene in vivo.The expression of PD-L1 on tumor cells was significantly attenuated by knocking out Cdk5,leading to effective tumor growth inhibition in murine melanoma and lung metastasis suppression in triple-negative breast cancer.Importantly,we demonstrated that aPBAE/Cas9-Cdk5 treatment elicited strong T cell-mediated immune responses in tumor microenvironment that the population of CD8^+T cells was significantly increased while regulatory T cells(Tregs)was decreased.It may be the first case to exhibit direct in vivo PD-L1 downregulation via CRISPR-Cas9 genome editing technology for cancer therapy.It will provide promising strategy for preclinical antitumor treatment through the combination of nanotechnology and genome engineering.

Role of senescence induction in cancer treatment

Cellular senescence is a form of permanent cell cycle arrest that can be triggered by a variety of cell-intrinsic and extrinsic stimuli, including telomere shortening,DNA damage, oxidative stress, and exposure to chemotherapeutic agents and ionizing radiation. Although the induction of apoptotic cell death is a desirable outcome in cancer therapy, mutations and/or deficiencies in the apoptotic signaling pathways have been frequently identified in many human cancer types,suggesting the importance of alternative apoptosis-independent therapeutic approaches for cancer treatment. A growing body of evidence has documented that senescence induction in tumor cells is a frequent response to many anticancer modalities including cyclin-dependent kinases 4/6 small molecule inhibitor-based targeted therapeutics and T helper-1 cytokine-mediated immunotherapy. This review discusses the recent advances and clinical relevance of therapy-induced senescence in cancer treatment.

聚焦超声治疗外阴上皮内非瘤变后对细胞周期素D 1和周期素依赖性蛋白激酶4表达的影响

目的探讨聚焦超声治疗外阴上皮内非瘤变(nonneoplastic epithelial disorders of vulva,NNEDV)后细胞周期素D 1(Cyclin D 1)和周期素依赖性蛋白激酶4(cyclin-dependent kinase 4,CDK 4)的表达及意义。方法回顾性分析2015年8月至2016年7月西南医科大学附属医院妇产科收治的20例NNEDV患者的皮损标本,设为病例组,经聚焦超声治疗后5~12月(平均8月)在原活检部位再次取材;选取因各种外阴疾病就诊局部活检后经病理证实为正常组织者10例为正常组。采用免疫组织化学法研究NNEDV患者聚焦超声治疗前后皮损中Cyclin D 1和CDK 4蛋白的表达。结果 NNEDV组织中Cyclin D 1和CDK 4蛋白阳性表达组织学评分治疗前高于治疗后及正常组(P<0.05),治疗后与正常组比较差异无统计学意义(P>0.05)。治疗前NNEDV患者Cyclin D 1和CDK 4在上皮组织棘细胞层/基底细胞层阳性表达组织学评分比值均高于治疗后及正常组(P<0.05),治疗后与正常组比较差异无统计学意义(P>0.05)。结论聚焦超声可以有效阻断NNEDV组织中Cyclin D 1、CDK 4的高表达而达到治疗目的,治疗后Cyclin D 1和CDK 4阳性细胞在NNEDV的上皮组织各层中的分布趋于正常。

Targeted lapatinib anti-HER2/ErbB2 therapy resistance in breast cancer:opportunities to overcome a difficult problem

Approximately 20%of invasive breast cancers have upregulation/gene amplification of the oncogene human epidermal growth factor receptor-2(HER2/ErbB2).Of these,some also express steroid receptors(the so-called Luminal B subtype),whereas others do not(the HER2 subtype).HER2 abnormal breast cancers are associated with a worse prognosis,chemotherapy resistance,and sensitivity to selected anti-HER2 targeted therapeutics.Transcriptional data from over 3000 invasive breast cancers suggest that this approach is overly simplistic;rather,the upregulation of HER2 expression resulting from gene amplification is a driver event that causes major transcriptional changes involving numerous genes and pathways in breast cancer cells.Most notably,this includes a shift from estrogenic dependence to regulatory controls driven by other nuclear receptors,particularly the androgen receptor.We discuss members of the HER receptor tyrosine kinase family,heterodimer formation,and downstream signaling,with a focus on HER2 associated pathology in breast carcinogenesis.The development and application of anti-HER2 drugs,including selected clinical trials,are discussed.In light of the many excellent reviews in the clinical literature,our emphasis is on recently developed and successful strategies to overcome targeted therapy resistance.These include combining anti-HER2 agents with programmed cell death-1 ligand or cyclin-dependent kinase 4/6 inhibitors,targeting crosstalk between HER2 and other nuclear receptors,lipid/cholesterol synthesis to inhibit receptor tyrosine kinase activation,and metformin,a broadly inhibitory drug.We seek to facilitate a better understanding of new approaches to overcome anti-HER2 drug resistance and encourage exploration of two other therapeutic interventions that may be clinically useful for HER+invasive breast cancer patients.