Disruption of the gastric epithelial barrier in Correa's cascade: Clinical evidence via confocal endomicroscopy.

BACKGROUND: Gastric epithelial barrier disruption constitutes a crucial step in gastric cancer (GC). We investigated these disruptions during the Correa's cascade timeline to correlate epithelial barrier dysfunction. MATERIALS AND METHODS: This study was conducted as a single-center, non-randomized clinical trial in China from May 2019 to October 2022. Patients with chronic atrophic gastritis (CAG), gastric intestinal metaplasia (GIM), low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), and intramucosal carcinoma underwent probe-based confocal laser endomicroscopy (pCLE). The pCLE scoring system was used to assess gastric epithelial barrier disruption semi-quantitatively. RESULTS: We enrolled 95 patients who underwent a pCLE examination. The control group consisted of 15 individuals, and the experimental group included 17 patients with CAG, 27 patients with GIM, 20 patients with LGIN, and 16 patients with early gastric cancer (EGC). Apart from CAG, which showed no significant difference compared to the control group, a significantly higher incidence of gastric epithelial barrier damage was found in the GIM, LGIN, and EGC groups compared to the control group (Kruskal-Wallis H test = 69.295, p < 0.001). There is no difference in LGIN patients between GIM and LGIN areas, and there is no difference between the two groups compared with the EGC group. The intestinal metaplasia area in LGIN patients causes more severe gastric epithelial damage compared to that in non-LGIN patients. Additionally, compared to control group, a significant difference (p < 0.001) was noted between individuals with Helicobacter pylori-positive atrophic gastritis and those with IM, whereas no significant difference (p > 0.05) was observed among individuals with H. pylori-negative atrophic gastritis. CONCLUSIONS: The gastric epithelial barrier remains dysfunctional from the initiation of H. pylori infection to GC progression. Beyond the "point of no return," subsequent carcinogenesis processes may be attributed to other mechanisms.

Potassium deficiency diagnosis method of apple leaves based on MLR-LDA-SVM.

Introduction: At present, machine learning and image processing technology are widely used in plant disease diagnosis. In order to address the challenges of subjectivity, cost, and timeliness associated with traditional methods of diagnosing potassium deficiency in apple tree leaves. Methods: The study proposes a model that utilizes image processing technology and machine learning techniques to enhance the accuracy of detection during each growth period. Leaf images were collected at different growth stages and processed through denoising and segmentation. Color and shape features of the leaves were extracted and a multiple regression analysis model was used to screen for key features. Linear discriminant analysis was then employed to optimize the data and obtain the optimal shape and color feature factors of apple tree leaves during each growth period. Various machine-learning methods, including SVM, DT, and KNN, were used for the diagnosis of potassium deficiency. Results: The MLR-LDA-SVM model was found to be the optimal model based on comprehensive evaluation indicators. Field experiments were conducted to verify the accuracy of the diagnostic model, achieving high diagnostic accuracy during different growth periods. Discussion: The model can accurately diagnose whether potassium deficiency exists in apple tree leaves during each growth period. This provides theoretical guidance for intelligent and precise water and fertilizer management in orchards.

Molecular subtypes predict the preferential site of distant metastasis in advanced breast cancer: a nationwide retrospective study.

Objective: This study aimed to explore possible associations between molecular subtypes and site of distant metastasis in advanced breast cancer (ABC). Methods: 3577 ABC patients were selected from 21 hospitals of seven geographic regions in China from 2012-2014. A questionnaire was designed to collect medical information regarding demographic characteristics, risk factors, molecular subtype, recurrence/metastasis information, and disease-free survival (DFS). The cancers were classified into Luminal A, Luminal B, HER2-enriched and Triple Negative subtypes. Chi-square test and multivariate Cox proportional hazard models were performed to explore the associations between molecular subtypes and distant metastasis sites. Results: A total of 2393 cases with molecular subtypes information were finally examined. Patients with Luminal A (51.1%) and Luminal B (44.7%) were most prone to bone metastasis, whereas liver metastasis was more frequently observed in HER2-enriched ABC patients (29.1%).The cumulative recurrence and metastasis rates of ABC patients at 36 months of DFS were the most significant within molecular types, of which Triple Negative was the highest (82.7%), while that of Luminal A was the lowest (58.4%). In the adjusted Cox regression analysis, Luminal B, HER2-enriched and Triple Negative subtypes increased the risk of visceral metastasis by 23%, 46% and 87% respectively. In addition, Triple Negative patients had a higher probability of brain metastasis (HR 3.07, 95% CI: 1.04-9.07). Conclusion: Molecular subtypes can predict the preferential sites of distant metastasis, emphasizing that these associations were of great help in choices for surveillance, developing appropriate screening and cancer management strategies for follow-up and personalized therapy in ABC patients.

Age at initial diagnosis and prognosis of breast cancer: a nationwide multicenter retrospective study in China.

Background: Several studies have indicated possible associations between age and the prognosis of breast cancer (BC), but limited data are available from hospital-based multicenter studies in China. This study aimed to explore the associations between age at initial diagnosis of BC and the risk of recurrence or metastasis among Chinese women with newly diagnosed advanced breast cancer (ABC) and provide treatment decision support for BC patients of different ages to medical workers. Methods: The medical records of patients newly diagnosed with ABC were obtained from 21 hospitals in seven geographic regions in China from 2012 to 2014. Patients' general information, clinicopathological features at first diagnosis, treatment information, and prognosis were retrospectively collected based on the self-designed case report form (CRF). Cox proportional hazards regression models were used to determine hazard ratios (HR) and 95% confidence intervals (CI) for the associations between age groups and the risk of recurrence and metastasis. Results: A total of 1,852 cases were included in the final analysis. Age at initial diagnosis was shown to be significantly related to hormone receptor status, human epidermal growth factor receptor 2 (HER2) status, molecular subtypes, and the number of lymph node metastasis (all P<0.05). Patients aged <35 years were more likely to have bone metastasis (45.6%). Patients aged ≥65 years had a lower percentage of receiving surgery (87.1%), adjuvant chemotherapy (61.3%), adjuvant radiotherapy (35.5%), and adjuvant endocrine therapy (30.6%) than the other groups (all P<0.05). Compared with patients aged <35 years, the risk of recurrence or metastasis in those aged 55-64 years was significantly higher (HRage 55-64 =1.24, 95% CI: 1.04-1.47), and the risk of bone metastasis and lung metastasis in those aged 35-44 years was lower (HRbone metastasis =0.74, 95% CI: 0.59-0.93; HRlung metastasis =0.70, 95% CI: 0.53-0.93). After adjusting for stage, grade, and molecular subtype, surgery, neoadjuvant chemotherapy, adjuvant chemotherapy, adjuvant radiotherapy, adjuvant endocrine therapy, and family history of BC, patients aged 35-44 years still had a significantly reduced risk of bone metastasis and lung metastasis by 31% and 52%, respectively (HRbone metastasis =0.69, 95% CI: 0.48-0.98; HRlung metastasis =0.48, 95% CI: 0.31-0.74). Conclusions: Age at initial diagnosis is related to the clinicopathological characteristics and treatment pattern. Although the risk of site-specific metastasis varies by age, age is not an independent factor influencing the risk of total recurrence and metastasis. In accordance with current clinical practice guidelines for BC, however, precise treatment shall be chosen personally for patients whose ages at initial diagnosis are different.

Comparisons of Treatment for HER2-Positive Breast Cancer between Chinese and International Practice: A Nationwide Multicenter Epidemiological Study from China.

OBJECTIVE: To better understand the status of medical treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer and the differences between the Chinese and the international clinical practice. METHODS: This was a retrospective, nationwide, multicenter, epidemiological study of advanced breast cancer patients from China. Between January 01, 2012, and December 31, 2014, a total of 3649 patients, covering 7 geographic regions and 21 institutions, participated in this series of studies. HER2-positive breast cancer was selected among the group and adopted into this study. In comparison, we summarized the demographics and clinical characteristics of HER2-positive breast cancer from the Surveillance, Epidemiology, and End Results (SEER) database. RESULTS: A total of 918 patients diagnosed as HER2-positive breast cancer patients were included. The median age at diagnosis was 46 years (ranging, 23 to 78) with a single-peak incidence. The proportions of stages II-IV at diagnosis and distance metastasis in viscera were more than half of the participants. In comparison, the prevalence of estrogen or progesterone receptor-positive expression and luminalB subtype was relatively lower than that of the United States. The receipt of chemotherapy was fairly higher, while the usage of targeted therapy was seriously insufficient. Tumor size was in significantly positive associations with the duration of targeted therapy (Kendall's correlation coefficient = 0.3, P < 0.0001), while no prohibitive variables among clinical characteristics were detected. CONCLUSION: Our study suggested that HER2-positive breast cancer patients were characterized as a younger trend, a lower prevalence of hormonal receptor (HR)-positive expression, and less accessible to anti-HER2 targeted therapy with insufficient duration over the past few years in China. Concerted efforts should be exerted for promising survival benefits in the future. The trial registration number is https://clinicaltrials.gov/ct2/show/NCT03047889.

Profile and outcome of receptor conversion in breast cancer metastases: a nation-wide multicenter epidemiological study.

Although receptor status including estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) of the primary breast tumors was related to the prognosis of breast cancer patients, little information is yet available on whether patient management and survival are impacted by receptor conversion in breast cancer metastases. Using data from the nation-wide multicenter clinical epidemiology study of advanced breast cancer in China (NCT03047889), we report the situation of retesting ER, PR and HER2 status for breast cancer metastases and evaluate the patient management and prognostic value of receptor conversion. In total, 3295 patients were analyzed and 1583 (48.0%) patients retesting receptor status for metastasis. Discordance in one or more receptors between the primary and the metastatic biopsy was found in 37.7% of women. Patients who remained hormone receptor (HR) positive in their metastases had similar progression-free survival of first-line and second-line treatment compared to patients with HR conversion (P > .05). In multivariate analysis, patients who showed ER conversion from negative to positive had longer disease-free survival (DFS) than patients who remained negative in their metastases (hazard ratio, 2.05; 95% confidence interval [CI], 1.45-2.90; P < .001). Patients with PR remained positive and had longer DFS than patients with PR conversion from negative to positive (hazard ratio, 0.56; 95% CI, 0.38-0.83; P = .004). Patients with PR conversion have shorter overall survival than patients with PR remained positive or negative (P = .016 and P = .041, respectively). Our findings showed that the receptors' conversions were common in metastatic breast cancer, and the conversion impacted the survival.

[Expression and Clinical Significance of CTGF in Patients with Multiple Myeloma].

OBJECTIVE: To detect the relationship between CTGF in the bone marrow of MM patients and osteolytic lesion of myeloma, moreover, to investigate the clinical significance of CTGF in MM. METHODS: Fifity-four MM patients treated in our hospital from March 2019 to April 2020 were enrolled, and 28 healthy volunteers were selected as the control group. The plasma in bone marrow of the patients was collected, and the ELISA was used to detect the level of CTGF in bone marrow plasma and the relationship between its and clinical characteristics were statistically analyzed. RESULTS: The CTGF level of MM patients was significantly higher than those in the healthy control group (P<0.001); the CTGF level in male patients was higher than that in female patients (P=0.007); the CTGF level in MM patients with osteolytic lesions was significantly higher than patients without osteolytic lesions and controls (P=0.007, P=0.001). The CTGF level in MM patients was positively correlated with the number of bone lesions (P<0.001, r=0.52). CTGF levels in patients with ≥3 bone lesions were significantly higher than those with <3 bone lesions and without bone lesions (P=0.014, P=0.002). ROC curve result showed that CTGF expression level shows a significant diagnostic value for MM bone disease (P<0.001). CONCLUSION: The abnormally high expression of CTGF level in MM patients is related to the degree of myelomas osteolytic lesions and can reflect the progress of MM.

Retracted: Effects of Nano-Hydroxyapatite/Polyetheretherketone-Coated, Sandblasted, Large-Grit, and Acid-Etched Implants on Inflammatory Cytokines and Osseointegration in a Peri-Implantitis Model in Beagle Dogs.

The article is withdrawn by the authors request.

Effect of Choukroun Platelet-Rich Fibrin Combined With Autologous Micro-Morselized Bone on the Repair of Mandibular Defects in Rabbits.

PURPOSE: The aim of this study was to explore the effect of Choukroun platelet-rich fibrin (PRF) combined with autologous micro-morselized bone on the repair of mandibular defects in rabbits. MATERIALS AND METHODS: Thirty-six healthy New Zealand rabbits were selected for the present study. After models of mandibular defects were established, rabbits were randomly divided into Choukroun PRF, autologous micro-morselized bone (autologous), Choukroun PRF combined with autologous bone (combined) and model groups. After the rabbits were sacrificed at 2, 8, and 12 weeks postoperatively, their bone formation was assessed by x-ray and scanning electron microscopy, and the histologic changes of the mandibular defect area were detected by hematoxylin and eosin staining. Cone-beam computed tomography was used to observe the size of the change of the mandibular defect area. Bone mineral density (BMD) was analyzed by dual-energy x-ray absorptiometry. RESULTS: The bone defect in the combined group showed better repair, increased bone mineral content, and denser callus than the other groups, and the defect area was filled with mature trabecular bone. In the Choukroun PRF and autologous groups, the defect area was smaller and filled with osteoporotic trabecular bone. A clear mandibular defect area was still observed in the model group. Compared with the other groups, the combined group showed more bone regeneration, more fibrous tissue regeneration, and greater bone maturity at all time points. The combined group had the highest BMD, there was no relevant difference in BMD between the Choukroun PRF and autologous groups, and the model group had the lowest BMD. BMD in all 4 groups increased with time. CONCLUSION: These findings indicate that Choukroun PRF combined with autologous micro-morselized bone can substantially improve the repair of mandibular defects in rabbits, and the effect is superior to Choukroun PRF or autologous micro-morselized bone alone.

Effects of Nano-Hydroxyapatite/Polyetheretherketone-Coated, Sandblasted, Large-Grit, and Acid-Etched Implants on Inflammatory Cytokines and Osseointegration in a Peri-Implantitis Model in Beagle Dogs.

BACKGROUND This study explored the effects of nano-hydroxyapatite/polyetheretherketone (n-HA/PEEK)- coated sandblasted, large-grit, and acid-etched (SLA) implants on inflammatory cytokines and osseointegration in peri-implantitis model beagle dogs. MATERIAL AND METHODS Peri-implantitis models were established. Eight beagle dogs were randomly and evenly assigned into SLA tied, SLA + n-HA/PEEK tied, SLA untied, or SLA + n-HA/PEEK untied groups. A special periodontal probe was used to detect the plaque index (PLI), probing depth (PD), and modified Sulcus Bleeding Index (mSBI). Gingival crevicular fluid was collected and an ELISA kit was utilized to detect IL-1, IL-6, and IL-17 levels. The colony-forming units were counted and the maximum shear strength of implants was tested using the axial pullout test. HE staining was used to detect the inflammation of peri-implant bone tissues. Osseointegration was observed through toluidine blue staining. Bone-to-implant contact (BIC) was obtained through histological observation and the mineral apposition rate (MAR) was calculated after immune fluorescent double staining. RESULTS The SLA tied group demonstrated higher levels of PLI, PD, mSBI, IL-1, IL-6, and IL-17 and a higher degree of inflammation than the SLA + n-HA/PEEK tied group. The tied groups also displayed similar results over the untied groups at the same time point. The maximum shear strength, BIC, and MAR in the SLA tied group were significantly lower than in the SLA + n-HA/PEEK tied group. CONCLUSIONS Our findings demonstrate that SLA + n-HA/PEEK implants can promote osseointegration and relieve the inflammation response of peri-implantitis in beagle dogs.

[Influence of ENSO Events on the Hydrogen (δ2H) and Oxygen (δ18O) Isotopic Values of Precipitation in Shanghai].

An analysis of the effect of ENSO events with different strengths on the isotopic composition of precipitation is conducted based on test data for 206 precipitation samples collected from January 2012 to February 2017 in Shanghai coupled with the archives for Nanjing, Wuhan, Fuzhou, and Hong Kong from 1961 to 2012 from the Global Network of Isotopes in Precipitation (GNIP) database. During the research periods, the δD and δ18O values in precipitation are lower in summer and autumn but higher in winter and spring. The slope and intercept of the atmospheric precipitation lines during El Niño events are larger than during other times, while anti-temperature, precipitation amount, and vapor pressure effects are more significant than during La Niña events. The δ18O and deuterium excess values (value of d) of rainfall in Shanghai during El Niño and La Niña events of varied strengths have an obvious negative correlation with the oceanic Niño index (ONI), sea surface temperature anomaly (SSTA), and the extreme and cumulative values of ONI. Moreover, ENSO events are closely intertwined with the correlation between δ18O isotopic value in precipitation, ONI, and SSTA.

RSK4 knockdown promotes proliferation, migration and metastasis of human breast adenocarcinoma cells.

RSK4 has been shown to inhibit the growth of certain cancer cells. The aim of this study was to construct a lentiviral vector of RSK4-shRNA (Lenti-RSK4-shRNA) to specifically block the expression of RSK4 in the human breast adenocarcinoma cell line MCF-7, and investigate the effect of the RSK4 gene on cell proliferation and invasion in vitro and in vivo. Lenti-RSK4-shRNA was stably transfected into MCF-7 cells. RSK4 mRNA and protein expression were measured by fluorescence quantitative RT-PCR and western blot analysis. Cell proliferation was evaluated by MTT assays and flow cytometric analysis. Invasion was evaluated by Transwell assays and xenograft nude mouse models. The expression of RSK4 mRNA, Ki-67 mRNA, cyclin D1 mRNA, CXCR4 mRNA and E-cadherin mRNA of tumor xenografts were detected by fluorescence quantitative RT-PCR. Significant decreases in RSK4 mRNA and protein expression was detected in MCF-7 cells carrying lentiviral RSK4-shRNA vector. The cell proliferation was significantly promoted in the RSK4-shRNA group as compared to that in the negative and blank control group. In addition, the number of cells in the S phase in the RSK4­shRNA group was significantly greater than the blank and negative control groups (P<0.05). Furthermore, the number of invading cells was increased in the RSK4-shRNA (P<0.05). In vivo, we also found that the knockdown of RSK4 promoted tumorigenicity and migration in the xenograft nude mouse model. In addition, we showed that the RSK4 mRNA and E-cadherin mRNA expression were significantly lower in the RSK4-shRNA group compared to that in negative and blank control group (both P<0.05), while the Ki-67 mRNA, cyclin D1 mRNA and CXCR4 mRNA were higher in the shRNA group compared to that in negative and blank control group (both P<0.05). In conclusion, downregulation of RSK4 expression is indicated to be associated with tumor cell proliferation and invasion, and silencing of the RSK4 may be involved in the development and progression of breast cancer through the changes of Ki-67, cyclin D1, CXCR4 and E-cadherin, and suggesting that RSK4 may act as a potential cancer suppressor gene and therapeutic target for the treatment of breast cancer.

Osteogenesis of bone marrow mesenchymal stem cells on strontium-substituted nano-hydroxyapatite coated roughened titanium surfaces.

OBJECTIVE: To investigate osteogenesis of bone marrow mesenchymal stem cells (BMSCs) on strontium-substituted nano-hydroxyapatite (Sr-HA) coated roughened titanium surfaces. METHODS: Sr-HA coating and HA coating were fabricated on roughened titanium surfaces by electrochemical deposition technique and characterized by field emission scanning electron microscope (FESM). BMSCs were cultured on Sr-HA coating, HA coating and roughened titanium surfaces respectively. Cell proliferation, alkaline phosphatase (ALP) activity, mineralized nodules formation and cell osteocalcin (OC) secretion were measured. RESULTS: Electrochemically deposited Sr-HA coating and HA coating had no effect on the proliferation of BMSCs and demonstrated that the materials have a good biocompatibility. BMSCs cultured on Sr-HA coating showed increased alkaline phosphatase activity, mineralized nodules formation, and cell OC secretion compared with the other two groups. Cells cultured on HA coating also showed increased biological activity compared with the roughened group. CONCLUSION: Sr-HA coated titanium surfaces by electrochemical deposition can promote osteogenesis of BMSCs in vitro and have the potential to shorten bone healing period and enhance implant osseointegration.

Clinical usefulness of breast-specific gamma imaging as an adjunct modality to mammography for diagnosis of breast cancer: a systemic review and meta-analysis.

PURPOSE: The purpose of this study was to assess the diagnostic performance of breast-specific gamma imaging (BSGI) as an adjunct modality to mammography for detecting breast cancer. METHODS: Comprehensive searches of MEDLINE (1984 to August 2012) and EMBASE (1994 to August 2012) were performed. A summary receiver operating characteristic curve (SROC) was constructed to summarize the overall test performance of BSGI. The sensitivities for detecting subcentimetre cancer and ductal carcinoma in situ (DCIS) were pooled. The potential of BSGI to complement mammography was also evaluated by identifying mammography-occult breast cancer. RESULTS: Analysis of the studies revealed that the overall validity estimates of BSGI in detecting breast cancer were as follows: sensitivity 95 % (95 % CI 93-96 %), specificity 80 % (95 % CI 78-82 %), positive likelihood ratio 4.63 (95 % CI 3.13-6.85), negative likelihood ratio 0.08 (95 % CI 0.05-0.14), and diagnostic odds ratio 56.67 (95 % CI 26.68-120.34). The area under the SROC was 0.9552 and the Q* point was 0.8977. The pooled sensitivities for detecting subcentimetre cancer and DCIS were 84 % (95 % CI 80-88 %) and 88 % (95 % CI 81-92 %), respectively. Among patients with normal mammography, 4 % were diagnosed with breast cancer by BSGI, and among those with mammography suggestive of malignancy or new biopsy-proven breast cancer, 6 % were diagnosed with additional cancers in the breast by BSGI. CONCLUSION: BSGI had a high diagnostic performance as an excellent adjunct modality to mammography for detecting breast cancer. The ability to identify subcentimetre cancer and DCIS was also high.

[Effects of breast cancer cells stably overexpressing RSK4 on growth of transplanted human breast cancer in severe combined immunodeficiency mice].

OBJECTIVE: To construct a breast cancer cell line MD-MB-231 stably overexpressing RSK4 gene and study its in vivo effects on tumor tumorigenesis. METHODS: The MD-MB-231 cells were transfected with pcDNA3.1/Neo and pcDNA3.1/Neo-RSK4 by lipofectamin transfection respectively. The stable expression of RSK4 (MR11 and MR12) and control vector (MN10 and MN11) were inoculated into severe combined immunodeficiency (SCID) mice subcutis to establish a model of human breast cancer in SCID mice. The xenograft tumor growth, invasion and metastasis were observed after 6 - 10 weeks. RESULTS: The stable cell lines MR11, MR12 and MN10, MN11 were screened successfully. We constructed the human breast cancer transplanted model and dissected SCID mice. After 6 weeks, SCID mice subcutis of the MN10/MN11 group yielded 10/10 metastatic tumors versus 6/10 and 7/10 in the MR11/MR12 group respectively. MR11 and MR12 showed much smaller tumor sizes and significantly reduced tumor volume and weight versus MN10 and MN11 (P < 0.001). In the control group, visceral metastasis developed in 80% (8/10) of mice while in metastasis developed in 40% (4/10) of mice injected with RSK4-overexpressing MDA-MB-231 cells. Histological examination of hematoxylin and eosin-stained paraffin sections of lungs revealed numerous metastases in mice injected with vector control cells whereas RSK4-overexpressing cells showed markedly decreased metastatic lesions. CONCLUSION: Transplanted human breast cancer in SCID mice closely correlates with the disease course of clinical tumor patients. Overexpression of RSK4 can inhibit tumor growth of transplanted human breast cancer in SCID mice.

Silencing of lysyl oxidase gene expression by RNA interference suppresses metastasis of breast cancer.

OBJECTIVE: The aim of this study was to investigate possible mechanisms of LOX gene effects on invasion and metastasis of breast cancer cells by RNA interference. METHODS: LOX-RNAi-LV was designed, synthesized, and then transfected into a breast cancer cell line (MDA-MB-231). Expression of LOX, MMP-2 and MMP-9 was determined by real-time PCR, and protein expression of LOX by Western blotting. Cell migration and invasiveness were assessed with Transwell chambers. A total of 111 cases of breast cancer tissues, cancer-adjacent normal breast tissues, and 20 cases of benign lesion tissues were assessed by immunohistochemistry. RESULTS: Expression of LOX mRNA and protein was suppressed, and the expression of MMP-2 and MMP-9 was significantly lower in the RNAi group than the control group (P<0.05), after LOX-RNAi-LV was transfection into MDA-MB-231 cells. Migration and invasion abilities were obviously inhibited. The expression of LOX protein in breast cancer, cancer-adjacent normal breast tissues and benign breast tumor were 48.6% (54/111), 26.1% (29/111), 20.0% (4/20), respectively, associations being noted with clinical stage, lymph node metastasis, tumor size and ER, PR, HER2, but not age. LOX protein was positively correlated with MMP-2 and MMP-9. CONCLUSION: LOX displayed an important role in invasion and metastasis of breast cancer by regulating MMP-2 and MMP-9 expression which probably exerted synergistic effects on the extracellular matrix (ECM).

[Mechanism of lysyl oxidase (LOX) in breast cancer invasion and metastasis].

OBJECTIVE: To investigate possible mechanism of silencing lysyl oxidase (LOX) gene by RNA interference affecting on invasion and metastasis of breast cancer cells. METHODS: LOX-RNAi-LV was designed and synthesized, which was transfected into breast cancer cell line MDA-MB-231. The expressions of LOX, MMP-2 and MMP-9 were determined by Real-time PCR in MDA-MB-231 cells, and the protein expression of LOX was determined by Western blot. The cells migration and invasion abilities were measured by cell migration and invasion test. 111 cases of breast cancer tissue and cancer-adjacent breast tissues and 20 cases of benign lesion tissues of LOX, MMP-2 and MMP-9 were detected by immunohistochemistry, and the relationship of LOX and clinicopathological characteristics was analyzed. RESULTS: The expression levels of LOX mRNA and protein were down-regulated obviously after transfecting LOX-RNAi-LV, with the inhibition rate 89.2% ± 1.3% and 84.4% ± 0.4% respectively. The relative expressions of MMP-2 and MMP-9 mRNA were 0.496 ± 0.021 and 0.571 ± 0.099 in RNAi group, which was significantly lower than that in negative control group (0.846 ± 0.047, 0.786 ± 0.042) and blank control group (1.000 ± 0.000, 1.000 ± 0.000) (both P < 0.05). Cell migration and invasion test showed the average cell numbers per field in the group RNAi were 47 ± 2 and 63 ± 2, was significantly lower than that in negative control group (100 ± 1, 118 ± 2) and blank control group (100 ± 1, 118 ± 2) (both P < 0.05). The expression of LOX protein in breast cancer, cancer-adjacent breast tissues and benign breast tumor were 48.6% (54/111), 26.1% (29/111), 20.0% (4/20), the expression of LOX protein in breast cancer was significantly higher than that in cancer-adjacent breast tissues and benign lesion tissues (P = 0.019). The expression of LOX protein was associated with clinical stage, lymph node metastasis, tumor size. Correlation analysis showed that LOX protein expression was significantly positive correlation with MMP-2 (r = 0.262, P = 0.005) and MMP-9 (r = 0.424, P = 0.000). CONCLUSION: LOX can promote invasion and metastasis of breast cancer; LOX and MMP-2, MMP-9 may have a synergistic role in promoting invasion and metastasis of breast cancer.

[Abnormal expression of RSK-4 and its clinical significance in breast cancer].

OBJECTIVE: To study the expression and clinical significance of ribosomal S6 kinase-4 (RSK-4) in breast cancer and explore the role of RSK-4 in the genesis and development of breast cancer. METHOD: The expression levels of RSK-4 mRNA and protein were detected in 56 cases of breast cancer and the normal breast tissues, as well as in 20 cases of breast benign lesions, by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. RESULTS: The expression rates of RSK-4 mRNA in breast cancer, the normal breast tissues and breast benign lesions were 48.2%, 76.8% and 75.0%, respectively. The expression level of RSK-4 mRNA in breast cancer was significantly lower than those in normal breast tissues and breast benign lesions tissues (P < 0.05). The expression level of RSK-4 significantly correlated with tumor size and clinical stage (P < 0.05).The expression rate of RSK-4 protein was 39.3% in breast cancer tissues, which was significantly lower than that of normal breast tissues (71.4%) and breast benign lesions (75.0%, P < 0.01). The expression level of RSK-4 protein was lower in breast cancer with large tumor, high clinical stage and lymph node metastasis. In 56 cases of breast cancer samples, the consistency rate of RSK-4 mRNA and protein was 73.2%. A significant correlation was found between RSK-4 mRNA and protein (χ² = 10.254, P < 0.05). CONCLUSION: The down-regulation of RSK-4 expression in breast caner suggests that it is a breast cancer suppressor gene, and the lack or down-regulation of RSK-4 expression is involved in the genesis and progression of breast cancer.

[Screening the differential expression of adriamycin-resistance related genes of breast cancer by cDNA microarray].

OBJECTIVE: To study the differential gene expression of adriamycin-resistance of breast cancer cell line MCF-7/ADR as compared with its parent cell MCF-7 and screen the related genes. METHODS: The in vitro inhibitory rate of MCF-7/ADR and MCF-7 cell lines to ADM (adriamycin) was examined by MIT assay. Then a cDNA microarray representing 14,755 genes was used to analyze the expression profiles of these two breast cancer cell lines. RESULTS: The inhibitory rate of MCF-7/ ADR to ADM was lower than that of MCF-7(P <0.05)and the drug resistance to ADR of MCF-7/ADR was stronger than that of MCF-7. There were 2374 differential expression genes in MCF-7/adr and MCF-7 cell lines, of which 1099 genes upregulated with 99 genes 10-fold upregulated and 1275 genes downregulated with 71 genes 10-fold downregulated. The important upregulated genes were Bcl-2, GSTP1, c-myc, MMP-1 and NNMT while those downregulated ones p53, p21, p27 and CYPIA1. CONCLUSION: Drug resistance of breast cancer is a complicated process involving the expression of many upregulated or downregulated genes. The application of gene chip in screening drug-resistant genes may be a new approach for selecting the optimal chemotherapeutic regimens. [Key words]

Use of a DNA microarray for simultaneous detection of antibiotic resistance genes among staphylococcal clinical isolates.

We developed a multiplex asymmetric PCR (MAPCR)-based DNA microarray assay for characterization of the clinically relevant antibiotic resistance genes leading to penicillin, methicillin, aminoglycoside, macrolide, lincosamide, and streptogramin B (MLS(B)) resistance in staphylococci. The DNA-based assay involves detection of specific conserved regions of the mecA, blaZ (methicillin and penicillin resistance), aac(6')-Ie-aph(2'') (aminoglycoside resistance), ermA and ermC genes (MLS(B) resistance), and the msrA gene (macrolide and streptogramin B resistance). The microarray uses a variable sequence region of the 16S rRNA gene to broadly differentiate between Staphylococcus aureus and other coagulase-negative staphylococci (CoNS). The performance of the microarray was validated with a total of 178 clinically important S. aureus and 237 CoNS isolates, with correlations of 100% for S. aureus to CoNS discrimination and more than 90% for antibiotic resistance between the genotypic analysis determined by the microarray and the phenotype determined by standard methods of species identification and susceptibility testing. The major discrepant results were 17 mecA-positive CoNS and 60 aac(6')-Ie-aph(2'')-positive CoNS isolates measured by microarray that were susceptible to the corresponding antibiotics based on disk diffusion assay. Overall, this microarray-based assay offers a simultaneous, fast (< or =5 h), and accurate identification of antibiotic resistance genes from a single colony, as well as species classification. Our extensive validation of the microarray suggests that it may be a useful tool to complement phenotypic susceptibility testing in clinical laboratories and to survey the spread of antibiotic resistance determinants in epidemiological studies.