The inhibition of cyclin-dependent kinases (CDKs) is considered a promising strategy for cancer treatment due to their role in cell cycle regulation. However, CDK inhibitors with no selectivity among CDK families have not been approved. A CDK inhibitor with high selectivity for CDK4/6 exhibited significant treatment effects on breast cancer and has become a heavy bomb on the market. Subsequently, resistance gradually decreased the efficacy of selective CDK4/6 inhibitors in breast cancer treatment. In this review, we first introduce the development of selective CDK4/6 inhibitors and then explain the role of CDK2 activation in inducing resistance to CDK4/6 inhibitors. Moreover, we focused on the development of CDK2/4/6 inhibitors and selective CDK2 inhibitors, which will aid in the discovery of novel CDK inhibitors targeting the cell cycle in the future.
Humans ; Cell Cycle/drug effects* ; Protein Kinase Inhibitors/chemistry* ; Cyclin-Dependent Kinases/metabolism* ; Neoplasms/genetics* ; Antineoplastic Agents/pharmacology* ; Animals ; Breast Neoplasms/enzymology* ; Cyclin-Dependent Kinase 4/metabolism*

Objective: To observe the platinum drugs resistance effect of N-acetyltransferase 10 (NAT10) overexpression in breast cancer cell line and elucidate the underlining mechanisms. Methods: The experiment was divided into wild-type (MCF-7 wild-type cells without any treatment) group, NAT10 overexpression group (H-NAT10 plasmid transfected into MCF-7 cells) and NAT10 knockdown group (SH-NAT10 plasmid transfected into MCF-7 cells). The invasion was detected by Transwell array, the interaction between NAT10 and PARP1 was detected by co-immunoprecipitation. The impact of NAT10 overexpression or knockdown on the acetylation level of PARP1 and its half-life was also determined. Immunostaining and IP array were used to detect the recruitment of DNA damage repair protein by acetylated PARP1. Flow cytometry was used to detect the cell apoptosis. Results: Transwell invasion assay showed that the number of cell invasion was 483.00±46.90 in the NAT10 overexpression group, 469.00±40.50 in the NAT10 knockdown group, and 445.00±35.50 in the MCF-7 wild-type cells, and the differences were not statistically significant (P>0.05). In the presence of 10 μmol/L oxaliplatin, the number of cell invasion was 502.00±45.60 in the NAT10 overexpression group and 105.00±20.50 in the NAT10 knockdown group, both statistically significant (P<0.05) compared with 219.00±31.50 in wild-type cells. In the presence of 10 μmol/L oxaliplatin, NAT10 overexpression enhanced the binding of PARP1 to NAT10 compared with wild-type cells, whereas the use of the NAT10 inhibitor Remodelin inhibited the mutual binding of the two. Overexpression of NAT10 induced PARP1 acetylation followed by increased PARP1 binding to XRCC1, and knockdown of NAT10 expression reduced PARP1 binding to XRCC1. Overexpression of NAT10 enhanced PARP1 binding to LIG3, while knockdown of NAT10 expression decreased PARP1 binding to LIG3. In 10 μmol/L oxaliplatin-treated cells, the γH2AX expression level was 0.38±0.02 in NAT10 overexpressing cells and 1.36±0.15 in NAT10 knockdown cells, both statistically significant (P<0.05) compared with 1.00±0.00 in wild-type cells. In 10 μmol/L oxaliplatin treated cells, the apoptosis rate was (6.54±0.68)% in the NAT10 overexpression group and (12.98±2.54)% in the NAT10 knockdown group, both of which were statistically significant (P<0.05) compared with (9.67±0.37)% in wild-type cells. Conclusion: NAT10 overexpression enhances the binding of NAT10 to PARP1 and promotes the acetylation of PARP1, which in turn prolongs the half-life of PARP1, thus enhancing PARP1 recruitment of DNA damage repair related proteins to the damage sites, promoting DNA damage repair and ultimately the survival of breast cancer cells.
Breast Neoplasms/enzymology* ; Cell Line, Tumor ; Drug Resistance, Neoplasm ; Female ; Humans ; MCF-7 Cells ; N-Terminal Acetyltransferases/metabolism* ; Organoplatinum Compounds/pharmacology* ; Oxaliplatin/pharmacology* ; X-ray Repair Cross Complementing Protein 1

The present study was aimed to investigate the effect of Janus kinase 3 (JAK3) on the migration of breast cancer cells and the underlying mechanism. The expression of JAK3 in breast cancer MCF-7 cells was silenced by siRNA (siJAK3). The migration ability of MCF-7 cells was detected by scratch test. The activity of store-operated calcium channel (SOCC) was detected by fluorescence calcium imaging. The expression levels of Orai1 and STIM1, key molecules in the process of store-operated calcium entry (SOCE) were detected by Western blot and RT-PCR. The results showed that 2-APB, an inhibitor of SOCC, could inhibit the migration ability of MCF-7 cells. siJAK3 transfection significantly inhibited the migration ability of MCF-7 cells, decreased the activity of SOCC, and down-regulated mRNA and protein expression levels of Orai1 and Stim1. Over-expression of Orai1 or STIM1 in JAK3-silenced cells restored their migration ability. These results suggest that JAK3 facilitates the migration of breast cancer cells by SOCC.
Breast Neoplasms ; enzymology ; Calcium ; metabolism ; Calcium Channels ; metabolism ; Cell Movement ; physiology ; Gene Expression Regulation, Neoplastic ; Humans ; Janus Kinase 3 ; genetics ; metabolism ; MCF-7 Cells ; ORAI1 Protein ; genetics

Metastasis is responsible for the majority of cancer-related deaths and prevention of metastasis remains a big challenge for cancer therapy. Cucurbitacin B (Cuc B) is a natural triterpenoid with potent anticancer activities while its effect on metastasis remains unclear. In the present study, the inhibitory effect and mechanisms of Cuc B on metastasis were investigated in MDA-MB-231 breast cancer cells. The cells were treated with or without Cuc B, and the cytotoxicity was determined by MTT assay. The effect of Cuc B on metastasis was evaluated with wound healing, transwell, and adhesion assays. Furthermore, the adhesion of cancer cells to endothelial cells was determined. The protein expression was determined by Western blotting. Cuc B (< 100 nmol·L) showed no obvious cytotoxicity to MDA-MB-231 cells, but significantly inhibited migration, invasion, and adhesion to Matrigel, fibronectin, type I collagen, and endothelial cells. Cuc B dramatically inhibited the phosphorylation of focal adhesion kinase (FAK) and paxillin in dose- and time-dependent manners. Furthermore, Cuc B induced intracellular reactive oxygen species (ROS) generation, which could be reduced by N-acetyl-l-cysteine (NAC). In addition, NAC pretreatment could reverse Cuc B-induced suppression of migration and adhesion, expression of FAK, but showed no effect on paxillin expression. In summary, Cuc B suppressed ROS-dependent metastasis through FAK pathway in breast cancer MDA-MB-231 cells, demonstrating novel mechanisms for the anticancer effects of Cuc B.
Acetylcysteine ; pharmacology ; Antineoplastic Agents ; pharmacology ; Breast Neoplasms ; enzymology ; metabolism ; pathology ; physiopathology ; Cell Adhesion ; drug effects ; Cell Line, Tumor ; Cell Movement ; drug effects ; Collagen Type I ; metabolism ; Dose-Response Relationship, Drug ; Down-Regulation ; drug effects ; Female ; Fibronectins ; metabolism ; Focal Adhesion Kinase 1 ; metabolism ; Humans ; Neoplasm Invasiveness ; pathology ; Neoplasm Metastasis ; pathology ; Paxillin ; metabolism ; Phosphorylation ; drug effects ; Reactive Oxygen Species ; metabolism ; Triterpenes ; antagonists & inhibitors ; chemistry ; pharmacology

OBJECTIVETo study the relationship between fibrotic focus (FF) and carbonic anhydrase (CA) IX in invasive ductal carcinomas (IDC) of the breast.

METHODSIn 167 cases of IDC, the FF was assessed morphologically, and expression of ER, PR and CA IX was evaluated using MaxVision immunohistochemistry.

RESULTSThe expression of CA IX in IDC with and without FF was 56.3% (45/80) and 28.7% (25/87) respectively, with significant difference (P=0.001). In IDC with FF, the CA IX expression of tumor cells in tumors with CA IX-positive fibroblasts (35/40, 87.5%) was significantly (P<0.001) higher than that in tumors with CA IX-negative fibroblasts (10/40, 25.0%). In IDC with FF, the CA IX expression of fibroblasts of FF in grade 3 IDC (23/33, 69.7%) was significantly (P=0.006) higher than that in grade 1+2 tumors (17/47, 36.2%). The ER and PR expression of tumor cells in tumors containing CA IX-negative fibroblasts was 72.5% (29/40) and 65.0% (26/40) respectively, whereas the ER and PR expression of tumor cells in tumors containing CA IX-positive fibroblasts was 50.0% (20/40) and 42.5% (17/40) respectively; the difference was statistically significant (for both ER and PR, P=0.04). The age of patients with tumors containing CA IX-negative fibroblasts was significantly (P=0.002) older than those containing CA IX-positive fibroblasts. The FF diameter/tumor diameter in tumors containing CA IX-positive fibroblasts was significantly larger than those containing CA IX-negative fibroblasts. (3) For the groups of tumor size≤2 cm and tumor size between 2 cm to 5 cm, the diameter of the fibrotic focus was significantly (P<0.01) smaller than the fibrotic focus size of tumors>5 cm in size.

CONCLUSIONSCA IX expression is correlated with FF, and that in fibroblasts of FF correlated with patients' age, tumor grade, hormone receptors and FF diameter/tumor diameter. CA IX expression in FF might be a marker for poor prognosis in patients with breast cancer.

Age Factors ; Antigens, Neoplasm ; Breast Neoplasms ; metabolism ; pathology ; Carbonic Anhydrase IX ; Carbonic Anhydrases ; Carcinoma, Ductal, Breast ; enzymology ; pathology ; Female ; Fibroblasts ; metabolism ; Humans ; Immunohistochemistry ; Neoplasm Grading ; Neoplasm Proteins ; Receptors, Estrogen ; metabolism ; Receptors, Progesterone ; metabolism

27-O-(E)-p-coumaric acyl ursolic acid( DY-17) from Ilex latifolia is a compound of the monomer. To investigate the DY-17 inducing apoptosis in the human breast cancer cell line, the MDA-MB-231 cells were used as research object in this experiment. The proliferation activity of the MDA-MB-231 cells stimulated with the different concentrations of DY-17 (20, 40 µmol · L(-1)) was detected at different time( 12, 24, 36, 48, 60,72 h) . We surveyed the DY-17 inducing apoptosis of the MDA-MB-231 cells with the fluorescent staining technology. The rate of MDA-MB-231 cells apoptosis and necrosis was determined by flow cell cytometry (FCC). Moreover, expression of JNK, phosphorylated JNK, Bax, PARP shear and caspase-3 shear related to JNK/SAPK pathways were investigated in every group ( control group, EGF group, EGF + DY-17 40 µmol · L(1) group and EGF + SP600125 group) with Western blot. The MTT results showed that, in the presence of DY-17, the proliferation activity of MDA-MB-231 cells decreased in a dose-dependent and time-dependent manner. The apoptosis and necrosis rates of MDA-MB-231 cells with DY-17(20, 40 µmol · L(-1)) groups was respectively 31.86%, 49.91% by flow cytometry and significantly increased compared with control group under Fluores- cence microscopy. Up-regulation of the JNK phosphorylation protein expression was observed in EGF group compared with control group. In addition, markedly decreased the expression of JNK phosphorylation protein were also surveyed in EGF + DY-17 40 µmol · L(-1) group compared with EGF group. The expression of Bax, shear PARP and shear caspase-3 protein in EGF + DY-17 40 µmol · L(-1) group were significantly increased in comparison with EGF group. The results showed DY-17 induced apoptosis of human breast cancer MDA-MB-231 cell line related to down-regulating JNK/SAPK signal pathways.
Apoptosis ; drug effects ; Breast Neoplasms ; drug therapy ; enzymology ; genetics ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Female ; Humans ; MAP Kinase Kinase 4 ; genetics ; metabolism ; Mitogen-Activated Protein Kinase 8 ; genetics ; metabolism ; Signal Transduction ; drug effects ; Triterpenes ; chemistry ; pharmacology

To study the effect of sodium aescinate in inducing human breast cancer MCF-7 cells apoptosis and its possible mechanism. MTT assay was used to detect the inhibitory effect of sodium aescinate on the proliferation of MCF-7 cells. The morphological changes were observed under inverted microscope. DAPI nuclear staining was used to detect the changes in cell nucleus. Annexin V-FITC/PI flow cytometry was adopted to test the apoptosis rate. Changes in apoptosis-related proteins (PARP, cleaved caspase-8 and pro-caspase-3), cell survival-associated signal molecules (AKT and ERK) and their common upstream kinase SRC was detected by Western blotting. The result showed that after different concentrations of sodium aescinate were used to treat breast cancer MCF-7 cells, they inhibited the proliferation of MCF-7 cells in a dose-dependent manner, induced cell apoptosis (typical morphological changes in nucleus, significant increase in cell apoptosis rate). The expressions of cleaved PARP and caspase-8 increased, while the expression of pro-caspase-3 decreased, which further verified sodium aescinate's effect in inducing cell apoptosis. Sodium aescinate significantly inhibited the phosphorylation of cell survival-related signal molecules (AKT, ERK) and down-regulate the activation of their common up-stream kinase SRC. The findings indicated that sodium aescinate can block signals transiting to downstream molecules AKT, ERK, inhibit the proliferation of breast cancer cell MCF-7 cell apoptosis and induced cell apoptosis by suppressing the activation of SRC.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Breast Neoplasms ; drug therapy ; enzymology ; genetics ; physiopathology ; Down-Regulation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; genetics ; metabolism ; Female ; Humans ; MCF-7 Cells ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Saponins ; pharmacology ; Signal Transduction ; drug effects ; Triterpenes ; pharmacology ; src-Family Kinases ; genetics ; metabolism

OBJECTIVETo investigate the significance of NADPH quinine oxidoreductase 1 (NQO1) protein overexpression on prognostic evaluation of head and neck squamous cell carcinoma (HNSCC).

METHODSNQO1 protein was detected in 162 of HNSCC, 45 cases of adjacent nontumor tissues and 26 samples of normal head and neck epithelia using EnVision immunohistochemical. Correlation between NQO1 overexpression and patients prognosis was also analyzed.

RESULTSThe positive rate and strongly positive rate of NQO1 protein were 84.0% (136/162) and 69.8% (113/162) in HNSCC, respectively, and both of which were significantly higher than either those in adjacent nontumor tissues and normal head and neck epithelia (both P < 0.01). NQO1 expression was significantly correlated with the clinical stage, pT and chemoradiotherapy of HNSCC (P < 0.01). Kaplan-Meier survival analysis showed that overall survival and disease-free survival rates were significantly higher in HNSCC patients with high level NQO1 expression than that those with low level of NQO1 expression (Log-rank = 6.625 , P = 0.010;Log-rank = 6.234 , P = 0.013). Additional analysis by Cox proportional hazard regression model showed that high level of NQO1 expression was an independent hazard predictor for overall survival of patients with HNSCC (Wald = 6.626, P = 0.008).

CONCLUSIONSNQO1 expression level is closely correlated with the progression and prognosis of patients with HNSCC. High level of NQO1 expression may be used as an important indicator for patients with poor prognostic HNSCC.

Breast ; enzymology ; Carcinoma, Squamous Cell ; enzymology ; mortality ; pathology ; Disease-Free Survival ; Female ; Head and Neck Neoplasms ; enzymology ; mortality ; pathology ; Humans ; Kaplan-Meier Estimate ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NADH, NADPH Oxidoreductases ; metabolism ; Prognosis ; Proportional Hazards Models

Radiation and drug resistance remain the major challenges and causes of mortality in the treatment of locally advanced, recurrent and metastatic breast cancer. Dysregulation of phospholipase D (PLD) has been found in several human cancers and is associated with resistance to anticancer drugs. In the present study, we evaluated the effects of PLD inhibition on cell survival, cell death and DNA damage after exposure to ionizing radiation (IR). Combined IR treatment and PLD inhibition led to an increase in the radiation-induced apoptosis of MDA-MB-231 metastatic breast cancer cells. The selective inhibition of PLD1 and PLD2 led to a significant decrease in the IR-induced colony formation of breast cancer cells. Moreover, PLD inhibition suppressed the radiation-induced activation of extracellular signal-regulated kinase and enhanced the radiation-stimulated phosphorylation of the mitogen-activated protein kinases p38 and c-Jun N-terminal kinase. Furthermore, PLD inhibition, in combination with radiation, was very effective at inducing DNA damage, when compared with radiation alone. Taken together, these results suggest that PLD may be a useful target molecule for the enhancement of the radiotherapy effect.
Breast Neoplasms/*drug therapy/*enzymology/pathology ; Cell Death/drug effects/radiation effects ; Cell Line, Tumor ; Cell Proliferation/drug effects/radiation effects ; DNA Damage ; Enzyme Activation/drug effects/radiation effects ; Enzyme Inhibitors/*pharmacology/*therapeutic use ; Extracellular Signal-Regulated MAP Kinases/metabolism ; Female ; Humans ; JNK Mitogen-Activated Protein Kinases/metabolism ; Phospholipase D/*antagonists & inhibitors/metabolism ; Radiation Tolerance/*drug effects ; Radiation, Ionizing ; p38 Mitogen-Activated Protein Kinases/metabolism

OBJECTIVETo evaluate the application of traditional cytomorphology, telomerase activity analysis and immunocytochemistry in cytopathologic diagnosis of pleural effusion and bronchoalveolar lavage samples.

METHODSA total of 123 agar-paraffin double-embedded pleural effusion and bronchoalveolar lavage fluid samples were enrolled into study. The cytomorphologic features were reviewed and correlated with immunocytochemical findings and telomerase activity.

RESULTSTelomerase activity was detected in 53 specimens using the real-time telomeric repeat amplification protocol. Amongst the cases studied, 39 samples (31.7%) contained overtly malignant cells while 20 cases (16.0%) were equivocal by conventional cytology. After verification by immunocytochemistry and clinical follow-up data, the diagnostic accuracy of telomerase activity and cytology was 87.0% and 82.1%, respectively. The sensitivity (97.6%) and specificity (100.0%) of cytology examination, when combined with telomerase activity analysis, were greater than those of cytology examination or telomerase activity analysis alone.

CONCLUSIONSTelomerase activity analysis can be used as an adjunctive investigative tool in cytology assessment of pleural effusion and bronchoalveolar lavage samples. The diagnostic accuracy can be further improved with the application of immunocytochemistry on agar-paraffin double-embedded cell block tissues.

Breast Neoplasms ; diagnosis ; enzymology ; pathology ; Bronchoalveolar Lavage Fluid ; chemistry ; Female ; Follow-Up Studies ; Humans ; Immunohistochemistry ; Lung Neoplasms ; diagnosis ; enzymology ; pathology ; Pleural Effusion ; diagnosis ; enzymology ; pathology ; Pleural Effusion, Malignant ; diagnosis ; enzymology ; pathology ; Sensitivity and Specificity ; Telomerase ; metabolism