Terminal Deoxynucleotidyltransferase-mediated Nick-end Labeling Assay Research Articles

Linc01124 promotes hepatoblastoma proliferation through the miR-24-3p/PI3K/AKT pathway

Children diagnosed with advanced hepatoblastoma (HB) generally have a poor prognosis and are in urgent need of effective treatment strategies. Long non-coding RNAs (lncRNAs) have been found to play crucial roles in various malignant tumors and can be potential targets for tumor diagnosis, treatment and prognosis. However, the role of most lncRNAs in HB pathogenesis is still not well understood. In this study, we investigated the expression of Linc01124 and its effect in HB. Clinical samples of HB patients were collected, and differentially expressed lncRNAs in HB were screened by quantitative real-time polymerase chain reaction (qRT-PCR). The Cell Counting kit-8 and 5-ethynyl-2′-deoxyuridine assay were used to detect cell proliferation in HB cells. The HB cells' apoptosis was assessed by the flow cytometry and terminaldeoxynucleotidyl transferase-mediated nick-end labeling assay. Then micro-RNAs and messenger RNAs targeted by Linc01124 were selected according to miRanda and miRTarbase. The gene pathways regulated by Linc01124 were predicted through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis. The prediction results were subsequently validated using qRT-PCR and Western blotting (WB). A Pearson's correlation analysis was conducted to examine the correlation between hsa-miR-24-3p and Linc01124, IL4, PDGFRB, BRCA1, and NOS3. In addition, HB cells were treated with a Linc01124 inhibitor and PI3K-Akt pathway activator to evaluate the involvement of miR-24-3p/PI3K/AKT in the regulation of HB cell function by Linc01124. Linc01124 was up-regulated in HB cells and tissues. Knockdown of Linc01124 can reduce cell proliferation and increase apoptosis. Bioinformatics analysis predicted that hsa-miR-24-3p could target Linc01124 and 8 genes involved in the PI3K-Akt pathway. qRT-PCR and WB experiments also demonstrated that disrupting Linc01124 expression could increase miR-24-3p expression and inhibit the PI3K/AKT pathway. Meanwhile, the target genes IL4, PDGFRB, BRCA1 and NOS3 expression were also down-regulated by silencing Linc01124. Hsa-miR-24-3p was found to have a negative association with Linc01124, IL4, PDGFRB, BRCA1 and NOS3. PI3K/AKT activator could rescue the decreased proliferation and increased apoptosis induced by Linc01124 knockdown. Linc01124 plays an oncogenic role by improving the activity of the PI3K/AKT pathway, which provides a theoretical basis for future research on the pathogenesis and progression mechanism of HB.

α-Pinene inhibits the growth of cervical cancer cells through its proapoptotic activity by regulating the miR-34a-5p/Bcl-2 signaling axis.

Among gynecological tumors, cervical cancer (CC) has the second-highest prevalence and mortality rate. α-Pinene is a bicyclic monoterpenoid compound extracted from pine needles that carried promising anticancer properties. Nevertheless, its effect on CC and the underlying mechanism has not yet been elucidated. Therefore, we investigated the effect of α-Pinene on apoptosis in CC via in vitro assays of flow cytometry (FCW), terminal deoxynucleotidyl transferase-mediated nick end labeling(TUNEL) assay, quantitative real-time polymerase chain reaction(qRT-PCR), and Western blot. Following that, we detected the proapoptotic function of α-Pinene on HeLa cells in vivo by TUNEL assay and immunofluorescence staining. Our results displayed that the α-Pinene inhibited the growth of HeLa cells and stalled the cells in the G0/G1 phase. Interestingly, we also detected that α-Pinene induced HeLa cells to apoptosis. The results investigated that α-Pinene induced HeLa cells apoptosis along with up-regulating the expression of Bax, Bid, caspase-9, caspase-3, miR-34a-5p, and down-regulating the expression of Bcl-2 in vitro. At the same time, the expression levels of target genes in vivo were consistent with those in vitro. Our experiment proved that α-Pinene promoted apoptosis, which will be used to hopefully maximize the therapeutic strategies in clinical studies in CC.

Quercetin regulates vascular endothelium function in chronic renal failure via modulation of Eph/Cav-1 signaling.

Arteriovenous fistula (AVF) is frequently believed to be the best vascular access for chronic renal failure (CRF) patients. Vascular endothelial cell dysfunction has been implicated in AVF maturation. Quercetin (Quer) is a natural polyphenolic compound widely used in traditional Chinese medicine. We aimed to uncover the impacts of Quer on vascular endothelial cells in a CRF rat model and human umbilical vein endothelial cells (HUVECs) stimulated by lipopolysaccharide (LPS) and serum from rat with CRF. Blood urea nitrogen and serum creatinine levels were tested in CRF rat model after administration of Quer. H&E staining was used to estimate endothelial damage. Nitric oxide (NO), endothelial NO synthase (eNOS), EPH receptor B4 (EphB4), EphrinB2, and p-caveolin-1 (p-Cav-1) levels in the serum were examined by enzyme-linked immunosorbent assay. Western blot was employed to analyze the expressions of eNOS, phosphorylated (p)-eNOS, EphB4, and Cav-1 in arterial tissues and HUVECs. Cell counting kit-8 was applied for assessing cell proliferation. TUNEL(terminal-deoxynucleotidyl transferase-mediated nick end labeling) assay was employed to estimate cell apoptosis. Results showed that Quer ameliorated renal function impairment and endothelial injury in vivo. Meanwhile, Quer boosted the proliferation and suppressed the apoptosis of HUVECs stimulated by LPS and serum from rat with CRF. Additionally, Quer elevated NO and eNOS levels, upregulated p-eNOS expression but downregulated EphB4, EphrinB2, and p-Cav-1 expressions. Moreover, EphB4 inhibitor had the similar effect as Quer treatment in HUVECs stimulated by LPS and serum from rat with CRF. Collectively, Quer might effectively regulate vascular function to prevent AVF failure in CRF via modulation of Eph/Cav-1 signaling.

Combination of anginex gene therapy and radiation decelerates the growth and pulmonary metastasis of human osteosarcoma xenografts.

Investigate whether rAAV‐anginex gene therapy combined with radiotherapy could decrease growth and pulmonary metastasis of osteosarcoma in mice and examine the mechanisms involved in this therapeutic strategy. During in vitro experiment, multiple treatment regimes (rAAV‐eGFP, radiotherapy, rAAV‐anginex, combination therapy) were applied to determine effects on proliferation of endothelial cells (ECs) and G‐292 osteosarcoma cells. During in vivo analysis, the same multiple treatment regimes were applied to osteosarcoma tumor‐bearing mice. Use microcomputed tomography to evaluate tumor size. Eight weeks after tumor cell inoculation, immunohistochemistry was used to assess the therapeutic efficacy according to microvessel density (MVD), proliferating cell nuclear antigen (PCNA), and terminal‐deoxynucleotidyl transferase‐mediated nick‐end labeling (TUNEL) assays. Metastasis of lungs was also evaluated by measuring number of metastatic nodules and wet weight of metastases. The proliferation of ECs and the tumor volumes in combination therapy group were inhibited more effectively than the other three groups at end point (P < 0.05). Cell clone assay showed anginex had radiosensitization effect on ECs. Immunohistochemistry showed tumors from mice treated with combination therapy exhibited the lowest MVD and proliferation rate, with highest apoptosis rate, as confirmed by IHC staining for CD34 and PCNA and TUNEL assays (P < 0.05). Combination therapy also induced the fewest metastatic nodules and lowest wet weights of the lungs (P < 0.05). rAAV‐anginex combined with radiotherapy induced apoptosis of osteosarcoma cells and inhibited tumor growth and pulmonary metastasis on the experimental osteosarcoma models. We conclude that the primary mechanism of this process may be due to sensitizing effect of anginex to radiotherapy.

Fisetin and polymeric micelles encapsulating fisetin exhibit potent cytotoxic effects towards ovarian cancer cells

BackgroundThe anti-tumor activities of Natural compounds and their derivatives are of great interest to pharmaceutical industries. Fisetin is one of prospective natural compounds in this regard but unfortunately with poor hydrophilicity.MethodsThe effects of unmodified and modified fisetin in cultured ovarian cancer cells were compared by transmission electronmicroscopy to determine apoptotic bodies, MTT assay to quantitate cell numbers, and fluorescence activated cell sorting analyse of various markers to determine the apoptotic state. In addition, the efficacy of fisetin and fisetin-micelles in vivo was determined by using immunocompromised mice. Apoptosis was measured by established markers using both western blot analysis and immunochemistry. Angiogenesis in a xenograft mouse model carring SKOV3 cells was evaluated by color Doppler ultrasound and immunohistochemistry.ResultMultiple lines of evidence indicated that fisetin and fisetin micelles induce apoptosis in ovarian cancer cells in a dose-dependent manner. Histological analysis, terminal deoxynucleotidyltransferase-mediated nick-end labeling assay, western blot, immunohistochemical detection and microvessel density detection demonstrated that fisetin and fisetin micelles induced increased tumor apoptosis, proliferation suppression and antiangiogenesis activities.ConclusionAs far as we know, the present study is the first time to demonstrate the potency of both fisetin and fisetin micelles inducing apoptosis in ovarian cancer cells. Further studies will be needed to validate the therapeutic potential of fisetin and fisetin micelles in ovarian cancer treatment.

Efficacy of granulocyte-macrophage colony-stimulating factor combined with metronomic paclitaxel in the treatment of Lewis lung carcinoma transplanted in mice.

Metronomic chemotherapy in combination with immunotherapy is an attractive approach in cancer therapy. The purpose of the present study was to investigate the anti-tumor effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) in combination with metronomic paclitaxel (MET PTX) on Lewis lung carcinoma transplanted in mice. In the present study, tumor-bearing mice survival time and tumor growth were monitored. The day after the end of the treatment, white blood cells were counted, and the number and maturation of dendritic cell were determined by flow cytometry. Besides, microvessel density and tumor cell proliferation were determined by immunohistochemistry, while apoptosis was determined by TUNEL (Terminal deoxynucleotidyl transferase-mediated nick end labeling) assay. Micro 18F-FDG PET/CT (18F-Fluorodeoxyglucose positron emission tomography/computed tomography) was used to obtain SUVmax values. White blood cells reduction was not observed in the mice treated with GM-CSF combined with MET PTX. Moreover, GM-CSF combined with MET PTX further reduced proliferation and microvessel density, promoted tumor apoptosis, increased the dendritic cells number and induced their maturation, with concomitant delay in tumor growth and improved survival. Taken together, GM-CSF combined with MET PTX exerted a synergistic anti-tumor effect against lung cancer in a mouse model through an antiangiogenic activity and inducing dendritic cells maturation without exerting pronounced adverse effects. Hence, combined metronomic chemotherapy and immunotherapy could be a potential strategy for the treatment of patients with advanced lung cancer.

The α7-nicotinic acetylcholine receptor mediates the sensitivity of gastric cancer cells to taxanes

Gastric cancer is difficult to cure because most patients are diagnosed at an advanced disease stage. Systemic chemotherapy remains an important therapy for gastric cancer, but both progression-free survival and disease-free survival associated with various combination regimens are limited because of refractoriness and chemoresistance. Accumulating evidence has revealed that the homomeric α7-nicotinic acetylcholine receptor (A7-nAChR) promotes human gastric cancer by driving cancer cell proliferation, migration, and metastasis. Therefore, A7-nAChR may serve as a potential therapeutic target for gastric cancer. However, the role of A7-nAChR in taxane therapy for gastric cancer was unclear. Cells were subjected to A7-nAChR knockdown (A7-nAChR KD) using short interfering RNA (siRNA). The anti-proliferative effects of taxane were assessed via 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL), and cell cycle distribution assays. A7-nAChR-KD cells exhibited low resistance to docetaxel and paclitaxel treatment, as measured by the MTT assay. Following paclitaxel treatment, the proportion of apoptotic cells was higher among A7-nAChR-KD cells than among scrambled control cells, as measured by cell cycle distribution and TUNEL assays. Further molecular analyses showed a reduction in the pAKT levels and a dramatic increase in the Bad levels in paclitaxel-treated A7-nAChR-KD cells but not in scrambled control cells. Following paclitaxel treatment, the level of Bax was slightly increased in both cell populations, whereas Poly (ADP-ribose) polymerase (PARP) cleavage was increased only in A7-nAChR-KD cells. These findings indicate that A7-nAChR-KD cells are more sensitive to paclitaxel treatment. We conclude that A7-nAChR may be a key biomarker for assessing the chemosensitivity of gastric cancer cells to taxane.

Alpha 7-nicotinic acetylcholine receptor mediates the sensitivity of gastric cancer cells to 5-fluorouracil.

Gastric cancer is the second most common cause of cancer mortality worldwide. Most gastric cancer patients are asymptomatic until the advanced stages, for which current therapeutic treatments are suboptimal. 5-Fluorouracil (5-FU), an antimetabolite agent, is widely used in gastric cancer therapy. However, the presence of drug resistance in gastric cancer patients reduces the cytotoxic activity of 5-FU. In gastric cancer, no research has yet been conducted to analyze the effect of alpha 7-nicotinic acetylcholine receptor (A7-nAChR) on the therapeutic response to 5-FU. In this study, we generated A7-nAChR knockdown (A7-nAChR-KD) AGS cells by a small interfering RNA (siRNA) technique in gastric cancer cells. The anti-proliferative effects of 5-FU were determined by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, a terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and cell cycle determination. We found that A7-nAChR-KD cells were more resistant to 5-FU treatment compared with the scrambled control cells according to the MTT assay. The apoptotic cell population was increased more in scrambled control cells treated with 5-FU than A7-nAChR-KD cells according to the cell cycle distribution and TUNEL assays. We analyzed expression levels of survival and apoptosis-associated proteins (pAkt, Akt, Mcl-1, Bcl-2, Bad, and Bax) altered by 5-FU treatment. Survival and antiapoptosis signaling (pAkt, Akt, Mcl-1 and Bcl-2) was downregulated, and the proapoptotic proteins (Bad and Bax) were upregulated in 5-FU-treated control cells but expression levels of Bcl-2, Bad, and Bad were not altered in 5-FU-treated A7-nAChR-KD cells. This is consistent with A7-nAChR-KD cells exhibiting more resistance to 5-FU treatment. In our study, we carried out an in vitro study on AGS gastric cancer cell line to elucidate the anticancer efficacy and molecular mechanisms of A7-nAChR silencing on 5-FU-induced cell death. The results clearly showed that depletion of A7-nAChR suppressed the drug sensitivity of gastric cancer cells to 5-FU treatment.

Ginsenoside-Rg1 inhibits endoplasmic reticulum stress-induced apoptosis after unilateral ureteral obstruction in rats

Aim: Endoplasmic reticulum (ER) stress and unfolded protein response (UPR) are implicated in many fibrotic diseases, including renal fibrosis. Whether Ginsenoside-Rg1 (G-Rg1) could attenuate renal fibrosis via suppression of ER stress and UPR has not been reported. The aim of this study was to explore the effect of G-Rg1 on ER stress and UPR-induced apoptosis in kidneys with unilateral ureteral obstruction (UUO) rat model. Methods: Twenty-four male Sprague–Dawley rats were randomly divided into control group, model group and G-Rg1 treatment group. G-Rg1 was administered to rats by intraperitoneal injection. Renal interstitial fibrosis in the model group was developed by UUO in rats. Renal function was estimated by the levels of serum creatinine (Scr) and blood urea nitrogen (BUN). Renal pathological damage was evaluated by hematoxylin and eosin (HE) and Masson’s trichrome staining. The ER stress was assessed with glucose-regulated protein (GRP) 78 expression, and the proapoptotic response was detected with CCAAT/enhancer-binding protein homologous protein (CHOP) and caspase-12 expressions by Western Blot. The number of apoptotic cells was determined by Terminal-deoxynucleotidyl Transferase Mediated Nick End Labeling (TUNEL) analysis. Results: UUO for 14 days aggravated renal function, renal damage and renal interstitial fibrosis, activated ER stress response (induction of GRP78 protein), enhanced the proapoptotic response (increase in CHOP and caspase-12 proteins) and increased the number of apoptotic cells (shown by the TUNEL assay). Treatment with G-Rg1 significantly ameliorates the renal pathological lesions and decreases expressions of ER stress-associated proteins and the level of apoptotic cells in kidneys. Conclusion: G-Rg1 suppresses renal cell apoptotic and fibrotic process partly through inhibition of ERS- and UPR-related apoptotic pathway in the kidneys after UUO.

Concurrent chemoradiotherapy with low-dose docetaxel inhibits the growth of DU-145 prostate cancer xenografts

Concurrent chemoradiotherapy (CCRT) has been widely used during the past decades in clinical trials and has now become a common treatment option in many clinical settings. The present study was designed to evaluate the efficacy of combining radiation with low-dose docetaxel in DU-145 prostate cancer xenograft models. Male BALB/c nude mice bearing human DU-145 prostate tumors were assigned to four treatment groups: (1) control, (2) docetaxel (10 mg/kg/week, i.v., ×3 weeks), (3) radiation (2 Gy, q.d. ×5, ×3 weeks), (4) CCRT (the combination of docetaxel and radiation). Treatment efficacy was determined by tumor volume and tumor regression measurements. The extent of apoptosis in tumors in response to treatments was assessed via terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assay. In addition, immunohistochemical staining of CD34 was done to quantify microvessel density in the tumors. Our in vivo studies using DU-145 xenograft models in nude mice showed that CCRT compared to either alone significantly inhibited tumor growth, and the percentages of tumor regression were 32.6, 44.2, and 68.6 % for docetaxel, radiation, and CCRT, respectively. Moreover, CCRT did not significantly affected mice weight as compared to docetaxel or radiation alone. TUNEL assays showed that significantly more apoptotic cells were induced in the tumors treated with CCRT than either treatment alone. Anti-CD34 immunohistochemical staining indicated that CCRT significantly inhibited tumor angiogenesis. These findings suggest that CCRT with low-dose docetaxel inhibits the growth of DU-145 prostate cancer xenografts, by enhancing apoptosis and suppressing angiogenesis. Based on these preclinical findings, we suggest that CCRT for the treatment of prostate cancer deserves further development.

Anti-Tumor Effect of Adipose Tissue Derived-Mesenchymal Stem Cells Expressing Interferon-β and Treatment with Cisplatin in a Xenograft Mouse Model for Canine Melanoma

Adipose tissue-derived mesenchymal stem cells (AT-MSCs) are attractive cell-therapy vehicles for the delivery of anti-tumor molecules into the tumor microenvironment. The innate tropism of AT-MSCs for tumors has important implications for effective cellular delivery of anti-tumor molecules, including cytokines, interferon, and pro-drugs. The present study was designed to determine the possibility that the combination of stem cell-based gene therapy with low-dose cisplatin would improve therapeutic efficacy against canine melanoma. The IFN-β transduced canine AT-MSCs (cAT-MSC-IFN-β) inhibited the growth of LMeC canine melanoma cells in direct and indirect in vitro co-culture systems. In animal experiments using BALB/c nude mouse xenografts, which developed by injecting LMeC cells, the combination treatment of cAT-MSC-IFN-β and low-dose cisplatin significantly reduced tumor volume compared with the other treatment groups. Fluorescent microscopic analysis with a TUNEL (terminal deoxynucleotidyl transferase-mediated nick-end labeling) assay of tumor section provided evidence for homing of cAT-MSC-IFN-β to the tumor site and revealed that the combination treatment of cAT-MSC-IFN-β with low-dose cisplatin induced high levels of cell apoptosis. These findings may prove useful in further explorations of the application of these combined approaches to the treatment of malignant melanoma and other tumors.

A molecular complex of bovine milk protein and oleic acid selectively kills cancer cells in vitro and inhibits tumour growth in an orthotopic rat bladder tumour model

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Novel intravesical therapies are needed for superficial bladder cancer that reduce the risk of infection associated with Bacillus Calmette-Guérin (BCG) and further destabilization of the urothelium associated with cytotoxic chemotherapy. Experimental therapies to date have included photodynamic therapy, oncolytic viruses, gene therapy (antisense oligonucleotides and silencing RNA), cytokine therapy, death receptor agonists (tumour-necrosis-factor-related apoptosis-inducing ligand and anti-DR5 monoclonal antibody), naturally occurring substances (curcumin and deguelin) and human α-lactalbumin made lethal to tumour cells (HAMLET). HAMLET, a natural occurring product in milk, induces apoptosis in urothelial cancer cells but has limitations in clinical application because of its human source. A previous study in patients with bladder cancer has demonstrated that intravesical HAMLET (daily for 5 days before tumour resection) caused selective apoptotic tumour cell death. BAMLET, the bovine equivalent of HAMLET, is a complex of bovine α-lactalbumin and oleic acid (bLAC) that has been shown in vitro to accumulate in the endolysosomal compartment of tumour cells and induce leakage of lysosomal cathepsins into the cytosol followed by activation of the pro-apoptotic protein Bax. This is the first in vivo study to show that BAMLET (bLAC) induces apoptosis in urothelial cancer cells and controls the growth of high risk urothelial cancer in a syngeneic rat orthotopic model. This same bladder cancer model system has been used to test other novel therapies, including BCG, and therefore provides a relative comparison of its effectiveness with other intravesical therapies. To investigate the efficacy of a complex of bovine α-lactalbumin and oleic acid (bLAC) to kill urothelial cancer cells in vitro and inhibit tumour growth and progression in a high risk bladder tumour model. The cytotoxicity of bLAC to a large panel of urothelial cell cancer (UCC) cells was tested by the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay, using bLA, the folded α-lactalbumin without oleic acid, as a control. The mechanism of bLAC-inducing cell death was evaluated by annexin V staining, TUNEL (terminal deoxynucleotidyl transferase mediated nick end labelling) assay and sub-G1 DNA analysis. The selective bLAC cytotoxicity was examined using multicellular spheroids consisting of UCC and non-transformed fibroblasts. Rats bearing orthotopic tumour received intravesical instillations (twice weekly, for 3 weeks) of bLAC, bLA, BCG or saline, starting 6 days after UCC (AY-27) cell inoculation. Animals were monitored for survival, toxicity and tumour growth control. A dose-dependent bLAC-inducing apoptotic-like cell death was shown in UCC cells tested, including cells refractory to classic apoptosis-inducing agents, whereas bLA showed little cytotoxicity. bLAC selectively destroyed cancer cells in spheroids. Intravesical bLAC therapy demonstrated marked reduction in tumour growth/progression and significantly prolonged animal survival vs saline instillations (P = 0.004, log-rank test) and showed comparable efficacy with BCG (standard) therapy. The findings identify bLAC as a new candidate for UCC therapy and suggests that topical administration of bLAC alone or with BCG to prevent progression of bladder cancer warrants further exploration.

E10A, an adenovirus-carrying endostatin gene, dramatically increased the tumor drug concentration of metronomic chemotherapy with low-dose cisplatin in a xenograft mouse model for head and neck squamous-cell carcinoma.

Most cancer chemotherapeutic agents are administered at the maximum-tolerated dose (MTD) in short cycles with treatment breaks. However, MTD-based chemotherapies are often associated with significant toxicity and treatment breaks allow the opportunity for tumor regrowth and acquisition of chemoresistance. To minimize these drawbacks, a metronomic strategy, in which chemotherapeutics are administered at doses significantly below the MTD without treatment breaks, has been suggested by many investigators. The antitumor effect of metronomic chemotherapy may be partially due to inhibition of tumor angiogenesis, and it could be enhanced by a combination therapy, including antiangiogenic agents. In this study, we evaluated the synergistic effect of E10A, an adenovirus carrying the endostatin gene, the most potent inhibitors of tumor angiogenesis, in combination with weekly low-dose cisplatin in a xenograft mouse model for head and neck squamous-cell carcinoma. The E10A induced mRNA and protein expressions of endostatin in H891 cells in vitro. E10A significantly enhanced the in vivo tumor growth inhibitory effect of cisplatin. Immunohistochemical analysis with a TUNEL (terminal deoxynucleotidyl transferase-mediated nick-end labeling) assay and anti-CD31 antibodies revealed that the combination of E10A and cisplatin induced high levels of cell apoptosis and inhibited tumor angiogenesis. Importantly, E10A increased the platinum concentrations in tumors to fivefold higher than that induced by cisplatin alone.

Comparative observation of freeze–thaw‐induced damage in pig, rabbit, and human corneal stroma

Although variations exist between species with respect to outcomes after cryopreservation, little is known about the differences in the susceptibility of the corneal stroma to cryoinjury. We performed this study to investigate freeze-thaw-induced damage in keratocytes and collagen in rabbit, pig, and human corneas. Rabbit, pig, and human. We prepared 250-microm-thick anterior stroma from rabbit, pig, and human corneas after scraping off the epithelium and endothelium. Each 250-microm-thick corneal stroma without epithelium was placed in a 50-mL tube, frozen with liquid N2 for 15 min and taken out to thaw rapidly at 37 degrees C. This procedure of rapid freezing and thawing was repeated three times. Differences between the species with respect to cells and collagen structures were examined using hematoxylin-eosin (H&E) staining, terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and transmission electron microscopy (TEM). We orthotopically transplanted the pig and rabbit corneal transplants after the triple freeze-thaw cycle into rabbit eyes and evaluated graft survival. On gross examination, rabbit corneas became opaque after the triple freeze-thaw procedure, while pig and human corneas remained transparent. Histologically, keratocytes were apoptotic on TUNEL assay and TEM in rabbit, pig, and human corneas. Collagen fibrils were fragmented and the arrangement of collagen fibrils was severely disturbed in rabbit corneas on H&E staining and TEM; collagen was well preserved in pig and human corneas. Rabbit corneal stroma underwent autolysis after transplantation, whereas the pig corneal stroma remained clear for 1 month. Our study showed that rabbit corneal stroma was more susceptible to freeze-thaw injury than pig and human corneas.

The effect of mifepristone on apoptosis and caspase-3 activation in human ovarian luteinized granulosa cells

Objective To investigate the effect of mifepristone, an oral contraceptive, on apoptosis in human ovarian luteinized granulosa cells. Study design Human ovarian luteinized granulosa cells were treated in vitro with 1.25, 2.5, 5.0, 10.0, or 20.0 μM of mifepristone. Nuclear morphology, apoptosis ratio, and level of caspase-3 expression were determined with immunofluorescence microscopy, the terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL) assay, and flow cytometry. Results We found that mifepristone-treated cells contained single condensed chromatin with multiple nuclear fragments, which is morphologic evidence of apoptosis. A significant difference was observed in the TUNEL assay between mifepristone-treated cells and control cells ( P < 0.05). Consistent with the results of the TUNEL assay, the fluorescence intensity of caspase-3 in drug-treated cells was also significantly different ( P < 0.05) from control cells; specifically, the difference between cells treated with different doses of drugs was much smaller and negligible. Conclusion From these results, we propose that mifepristone induces human ovarian luteinized granulosa cells to undergo apoptosis by activating caspase-3.

Docetaxel Followed by Castration Improves Outcomes in LNCaP Prostate Cancer–Bearing Severe Combined Immunodeficient Mice

Androgen ablation is the standard initial treatment for advanced prostate cancer; however, tumors eventually develop androgen independence and become incurable. Chemotherapy is commonly used after hormone treatment fails but has not shown significant survival benefit. Studies suggest that androgen ablation can select for a population of hormone-independent cells that are also relatively chemotherapy resistant. Thus, it may be therapeutically advantageous to target prostate cancer with chemotherapy before hormone ablation. This study was undertaken to determine the relative efficacy of such an approach in a preclinical model of prostate cancer. Severe combined immunodeficient mice bearing human LNCaP prostate tumors were treated with docetaxel and/or surgical castration applied singly, concurrently, or in different sequences. Treatment efficacy was determined by tumor volume and growth delay measurements. The extent of apoptosis in tumors in response to treatments was assessed via terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assays. In addition, Western blots were done to study the relative expression of Bcl-2 and Bax in the tumors. Docetaxel followed by castration showed the most potent antitumor effects. In contrast, with the exception of castration alone, castration followed by docetaxel produced the least antitumor activity. TUNEL assays confirmed that the density of apoptotic tumor cells was significantly greater for docetaxel followed by castration than for any other treatment. In tumors of mice treated with single modality therapies, Bax to Bcl-2 ratios decreased significantly after castration, whereas this ratio remained high after docetaxel treatment. A treatment sequence of docetaxel followed by hormone ablation may be more effective in treating prostate cancer than concurrent docetaxel/hormone therapy or hormone ablation followed by docetaxel.

Effect of Combination Therapy with a Novel Bisphosphonate, Minodronate (YM529), and Docetaxel on a Model of Bone Metastasis by Human Transitional Cell Carcinoma

Transitional cell carcinoma (TCC) of the urinary tract is a chemosensitive tumor. Most deaths from TCC of the urinary tract are caused by metastasis, which is resistant to conventional chemotherapy. Frequent sites of metastases from TCC of the urinary tract are regional lymph nodes, liver, lung, and bone. Of these distant metastases, bone metastasis is consistently resistant to cisplatin-based conventional chemotherapy. Therefore, in this study, we investigated whether or not a newly developed minodronate, YM529, could prevent osteolytic bone metastasis of human TCC and also enhance the effect of docetaxel in a bone tumor model of athymic nude mice. In the present study, we evaluated the effect of in vitro treatment with minodronate and/or docetaxel on the proliferation by cell count, the induction of apoptosis by terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and the biological activity of osteoclast by pit formation assay in human bladder cancer cell line, UMUC-14, and mouse osteoclast cells. In vivo, we examined the effect of minodronate in a bone tumor model of athymic nude mice, in which the percutaneous intraosseal injection in the tibia of UMUC-14, leads to osteolytic bone tumor, as a bone metastasis model. To examine whether or not minodronate could inhibit tumorigenicity and enhance the effect of the chemotherapeutic agent, docetaxel, we gave minodronate i.p. and/or docetaxel i.p. to nude mice 3 days after an intraosseal tumor implantation. Moreover, proliferation and the induction of apoptosis of cancer cells and osteoclasts in bone tumors were determined by immunohistochemistry and the TUNEL assay. In vitro: In vitro treatment with docetaxel inhibited proliferation and resorption pit-forming activity and induced apoptosis of mouse osteoclast cells and UMUC-14 cells. In vitro treatment with minodronate inhibited proliferation and activity and induced apoptosis of mouse osteoclast cells but not UMUC-14 cells. The treatment with minodronate enhanced the inhibition of proliferation and activity by docetaxel in osteoclasts. In vivo: In vivo combination therapy with docetaxel and minodronate significantly reduced the tumor incidence compared with the control (P < 0.05) and also growth of intraossal TCC in athymic nude mice compared with the control (P < 0.001), single therapy with docetaxel (P < 0.01), and minodronate (P < 0.05). Drug-induced body weight loss was not significantly different in any treatment group. Therapy with minodronate significantly enhanced inhibition of proliferation by docetaxel in osteoclasts of bone tumors compared with the control (P < 0.01), single therapy with docetaxel (P < 0.01), and minodronate (P < 0.05). These studies indicate that combination therapy with minodronate and docetaxel may be beneficial in patients with bone metastasis of human TCC in the urinary tract.

The Ras Effector RASSF2 Is a Novel Tumor-Suppressor Gene in Human Colorectal Cancer

Activation of Ras signaling is a hallmark of colorectal cancer (CRC), but the roles of negative regulators of Ras are not fully understood. Our aim was to address that question by surveying genetic and epigenetic alterations of Ras-Ras effector genes in CRC cells. The expression and methylation status of 6 RASSF family genes were examined using RT-PCR and bisulfite PCR in CRC cell lines and in primary CRCs and colorectal adenomas. Colony formation assays and flow cytometry were used to assess the tumor suppressor activities of RASSF1 and RASSF2. Immunofluorescence microscopy was used to determine the effect of altered RASSF2 expression on cell morphology. Mutations of K- ras , BRAF, and p53 were identified using single-strand conformation analysis and direct sequencing. Aberrant methylation and histone deacetylation of RASSF2 was associated with the gene's silencing in CRC. The activities of RASSF2, which were distinct from those of RASSF1, included induction of morphologic changes and apoptosis; moreover, its ability to prevent cell transformation suggests that RASSF2 acts as a tumor suppressor in CRC. Primary CRCs that showed K- ras /BRAF mutations also frequently showed RASSF2 methylation, and inactivation of RASSF2 enhanced K- ras -induced oncogenic transformation. RASSF2 methylation was also frequently identified in colorectal adenomas. RASSF2 is a novel tumor suppressor gene that regulates Ras signaling and plays a pivotal role in the early stages of colorectal tumorigenesis.

Facilitation of adenoviral wild-type p53-induced apoptotic cell death by overexpression of p33ING1 in T.Tn human esophageal carcinoma cells

To investigate the effect of p33(ING1) on wild-type p53 gene therapy, T.Tn human esophageal carcinoma cells were stably transfected with p33(ING1) cDNA. Infection with Ad-p53 (recombinant adenovirus containing wild-type p53) into p33-transfected cells reduced cell viability, while infection with empty vector had little effect. This reduced viability was shown to be due to apoptotic cell death by the TUNEL (terminal deoxynucleotidyl transferase-mediated nick end-labeling) assay. Following infection with Ad-p53, levels of p53 were similar in p33-expressing cells and in the parental line. However, levels of p21 and Mdm2 were elevated in p33-transfected cells. Nonetheless, this enhanced expression of Mdm2 appeared to be ineffective in downregulating p53. Transient transfection with mutant Mdm2 prior to Ad-p53 infection provided a significant protection as compared with cells transfected with wild-type Mdm2. These results imply a synergistic effect between p33 and p53 in the induction of apoptosis of human esophageal carcinoma cells. A role for Mdm2 in this synergism is suggested.

Doxorubicin-induced Apoptosis in Endothelial Cells and Cardiomyocytes Is Ameliorated by Nitrone Spin Traps and Ebselen: ROLE OF REACTIVE OXYGEN AND NITROGEN SPECIES

Doxorubicin (DOX) is a broad spectrum anthracycline antibiotic used to treat a variety of cancers. Redox activation of DOX to form reactive oxygen species has been implicated in DOX-induced cardiotoxicity. In this work we investigated DOX-induced apoptosis in cultured bovine aortic endothelial cells and cardiomyocytes isolated from adult rat heart. Exposure of bovine aortic endothelial cells or myocytes to submicromolar levels of DOX induced significant apoptosis as measured by DNA fragmentation and terminal deoxynucleotidyltransferase-mediated nick-end labeling assays. Pretreatment of cells with 100 microm nitrone spin traps, N-tert-butyl-alpha-phenylnitrone (PBN) or alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (POBN) dramatically inhibited DOX-induced apoptosis. Ebselen (20-50 microm), a glutathione peroxidase mimetic, also significantly inhibited apoptosis. DOX (0.5-1 microm) inactivated mitochondrial complex I by a superoxide-dependent mechanism. PBN (100 microm), POBN (100 microm), and ebselen (50 microm) restored complex I activity. These compounds also inhibited DOX-induced caspase-3 activation and cytochrome c release. PBN and ebselen also restored glutathione levels in DOX-treated cells. We conclude that nitrone spin traps and ebselen inhibit the DOX-induced apoptotic signaling mechanism and that this antiapoptotic mechanism may be linked in part to the inhibition in formation or scavenging of hydrogen peroxide. Therapeutic strategies to mitigate DOX cardiotoxicity should be reexamined in light of these emerging antiapoptotic mechanisms of antioxidants.