Multicenter phase II trial of S-1, paclitaxel and cisplatin triplet combination chemotherapy in patients with advanced gastric cancer

OBJECTIVE

The present study was conducted to evaluate the efficacy and safety of a combination regimen of S-1, paclitaxel plus cisplatin in patients with advanced gastric cancer.

METHODS

Patients with previously untreated metastatic or recurrent, measurable gastric cancer received intravenous paclitaxel 80 mg/m² plus cisplatin 30 mg/m² on days 1, 8 and S-1 35 mg/m² orally twice daily on days 1-14 based on a 3-week cycle.

RESULTS

Forty-four patients were enrolled in the current study, among whom 38 were assessable for efficacy and all assessable for toxicity. Two complete response and 24 partial responses were confirmed, giving an overall response rate of 59.1%. At a median follow-up of 11.4 months, the median time to progression and median overall survival was 9.4 (95% CI 6.8-12.1) months and 11.2 (95% CI 7.6-14.8) months, respectively. Grade 3/4 neutropenia occurred in 45 events (20.9%) and febrile neutropenia was observed in five events (2.3%). The common non-hematologic toxicity was nausea (grade 1/2, 27.2%) and diarrhea (grade 1/2, 9.0%).

CONCLUSION

The combination of S-1, paclitaxel and cisplatin was found to be well tolerated and effective in patients with advanced gastric cancer.

Abstract 610: Metformin augments rituximab and chemotherapeutic agents-induced apoptosis via mTOR inhibition in rituximab-resistant B lymphoma cell lines

With elusive mechanisms, a subgroup of NHL patients who treated with rituximab in combination with cytotoxic chemotherapeutic agents becomes unresponsive. Patients who relapsed lymphoma are known to have poorer outcome when treated with rituximab compared with treated without rituximab. Since activation of mTOR pathway has been recently suggested for progression of NHL, especially in salvage setting, we'd like to examine the effect of metformin which inhibits mTOR pathway in rituximab-resistant NHL. Three lymphoma cell lines (Raji, Raji-2R, Raji-4RH) were used, which were kindly given by Dr Czuczman MS from Rosewell Park Cancer Institute (Ref. Czuczmana MS et al. Clin Cancer Res 2008;14:1561, 2008;14:1550). These cells were treated with cisplatin, adriamycin, vincristine and rituximab in the absence or presence of metformin for 24, 48, 72 hrs. Cell growth and proliferation was evaluated by MTT assay and cell cycle progression was determined FACS analysis. To characterize molecular mechanisms involved in metformin-induced inhibition of cell proliferation, the level of BAX, BAK, Bcl-2, Bcl-XL, Mcl-1, AMPK, pAMPK, pACC, mTOR, p70S6K and S6K was determined by western blot analysis.

Compared with rituximab-sensitive cell line (RSCL) which is parental lymphoma cell, Raji, rituximab-resistant cell lines (RRCLs), that are Raji-2R and Raji-4RH, have shown decreased cytotoxicity in response to chemotherapeutic agents including cisplatin, adriamycin and vincristine as well as rituximab. However, cytotoxic effect of these chemotherapeutic agents and rituximab was improved in combination of metformin in both RSCL and RRCLs. To us surprise, a better synergistic inhibition of cell proliferation was found in RRCLs as a result of combination of metformin and chemotherapeutic agents or rituximab, suggesting that intracellular signaling pathway induced by metformin might not be overlapped to that by chemotherapeutic agent and rituximab. Notably, it has known that in RRCLs, the level of proapototic proteins, BAX, BAK, is relatively low compared to in RSCL decreased, but the expression of anti-apoptotic protein and AMPK activity is increased and dysregulation of mTOR pathway is found. Our data showed that metformin restored dysregulation of mTOR pathway in RRCLs, since activation of p70S6K and S6K posphorylation was decreased. At the same time, expression of BAX and BAK was increased and that of anti-apoptotic proteins was decreased.

Metformin enhances rituximab-induced and chemotherapy-induced apoptosis via mTOR inhibition in rituximab-resistant NHL.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 610.

Phase IV study evaluating efficacy of escalated dose of imatinib in chronic myeloid leukemia patients showing suboptimal response to standard dose imatinib

The aim of this phase IV study was to (1) to define efficacy of escalating dose imatinib in chronic myeloid leukemia (CML) patients showing suboptimal response to standard dose imatinib and (2) to find markers that predict the response to escalating doses of imatinib. CML patients in chronic phase (CP) who failed to achieve optimal response with 400 mg/day imatinib or patients in accelerated phase (AP) or blast crisis (BC) who failed to achieve complete hematologic response after 3 months of 400-600 mg/day imatinib were enrolled. CP patients received 600 mg/day, while AP/BC patients received 600-800 mg/day imatinib. Patients received imatinib for at least 12 months or until the disease progression or intolerable toxicity. Along with cytogenetic response (CyR), molecular response was assessed with BCR-ABL/ABL ratio. Baseline BCR-ABL gene mutation test was performed. Seventy-one patients (median age, 49.0 years, M:F = 50:21) received escalated dose imatinib. Grade 3 edema in two patients was the only nonhematologic toxicities more than grade 2. For evaluable patients, 30.8% of patients achieved CCyR at 6 months, and median time to treatment failure (TTFx) was 18.0 months. TTFx was longer in patients who achieved greater than 50% reduction in BCR-ABL/ABL within 6 months (early molecular responder (EMR)) compared with those who did not (non-EMR; p < 0.001). Of 31 patients who had mutational status data, three had mutation. All mutants failed to achieve CCyR. In conclusion, escalated dose imatinib shows considerable efficacy with tolerable toxicity in CML patients showing suboptimal response to standard dose imatinib. EMR is an early predictive marker for positive imatinib response.

An open, non-comparative, multicentre study on the impact of alfuzosin on sexual function using the Male Sexual Health Questionnaire in patients with benign prostate hyperplasia

OBJECTIVES

To determine the effect of alfuzosin on sexual function by using the Male Sexual Health Questionnaire (MSHQ) in men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

In this multicentre, open-label and non-comparative study, a total of 135 sexually active patients with LUTS were enrolled in Korea to receive alfuzosin 10 mg once daily for 12 weeks. International Prostate Symptom Score (IPSS) and a 25-item MSHQ exploring erection ejaculation and satisfaction with sex life were evaluated at baseline after 4 and 12 weeks of treatment.

RESULTS

Of 135 patients (age 58.8 years, duration of LUTS 2.6 years, mean values), 110 (81.5%) completed the study. The ejaculatory domain of the MSHQ significantly improved at the end-point in the intent-to-treat population (score difference of 2.24, p < or = 0.0001, n = 120). The domains of erection and sexual satisfaction improved at the end-point, but the score differences were not statistically significant. After the 12 weeks treatment, the total IPSS score significantly decreased from 17.9 to 12.1 (p < 0.0001), bother score decreased from 3.8 to 2.85 (p < 0.0001) and peak flow rate increased from 11.0 to 14.3 ml/s (p < 0.0001). A significant relationship between ejaculatory domains of MSHQ and IPSS was found. Four patients (2.9%) discontinued the trial for adverse event.

CONCLUSIONS

Based on the analysis of MSHQ scores before and after alfuzosin treatment, improvement was significant on ejaculatory function, in addition to improvement on LUTS and quality of life. MSHQ is a useful tool to evaluate the male sexual dysfunction.

A case of spine origin chondroblastoma metastasis to lung

Chondroblastoma is a rare benign cartilaginous neoplasm that accounts for approximately 1% of all bone tumors and characteristically arises in the epiphysis of a long bone, particularly the humerus, tibia, and femur. Chondroblastoma can affect people of all ages. It is, however, most common in children and young adults between the ages of 10 and 20 years. Although most chondroblastomas are cured by limited surgical procedures, occasional lesions behave more aggressively and may even metastasis. In this case a young man with pulmonary metastatic chondroblastoma on spine is presented. Unlike previously published examples of metastatic chondroblastoma, these metastasis developed before any operative manipulation of the primary tumor. And primary tumor site was also unusual. The histologic characteristics of the primary, metastatic tumors were those of a conventional chondroblastoma.

Relapsed or refractory nongastric marginal zone B-cell lymphoma: multicenter retrospective analysis of 92 cases

Over its long survival duration, marginal zone B-cell lymphoma (MZL) routinely involves frequent relapses. In this study, we conducted a retrospective analysis to identify the clinical features and outcomes of relapsed or refractory MZL. From 1995 to 2008, a total of 92 patients with relapsed MZL were retrospectively analyzed. The median age of our subjects was 53.5 years (range: 23-82 years). The most common primary sites of involvement were the orbit and ocular adnexa (28.3%) followed by the lymph node and lymphatic organs (23.9%), and multiple mucosa-associated lymphoid tissue (MALT) sites (13.0%). The median time to relapse from initial diagnosis was 25.5 months. Of the 53 patients with Stage I or II at diagnosis, 42 patients (79.2%) evidenced locoregional recurrence. Among these locoregional relapsed patients, 27 patients achieved CR (54.1%) or PR (18.9%). In addition to the 39 patients initially in advanced Stage III or IV, a total of 50 patients were in advanced stage at relapse. Among those patients with advanced stage at relapse, 44 patients were treated. The overall response rate was 54.5% (24 patients), with 18 CRs and 6 PRs. The median time to progression (TTP) was 34.1 months (95% CI: 11.3-56.9 months) and the estimated 5-year overall survival (OS) was 84.3%. The majority of them was controlled well with salvage treatment, and could achieve prolonged survival. However, patients' refractory to initial therapy and advanced relapse evidenced shorter TTP and OS. Thus, we need to consider more aggressive treatment in cases of refractory MZL or advanced relapsed MZL.

Clinical features and survival outcomes in patients with multiple myeloma: analysis of web-based data from the Korean Myeloma Registry

AIM

The Korean Multiple Myeloma Working Party performed a nationwide registration of multiple myeloma patients via a web-based data bank system.

METHODS

We retrospectively analyzed registered data from 3,209 patients since 1999.

RESULTS

The median overall survival (OS) was 50.13 months (95% confidence interval: 46.20-54.06 months). Patients < or =40 years demonstrated a longer OS than patients >65 years of age (median OS 71.13 vs. 36.73 months, p < 0.001). Patients who received novel agents at any time during their treatments showed a longer OS than patients who did not (median OS 42.23 vs. 55.50 months, p < 0.001). Response to treatment was associated with OS, with tandem autologous stem cell transplantation (SCT) producing longer OS than single autologous SCT.

CONCLUSIONS

We demonstrated associations between survival outcomes and treatment modalities as well as baseline disease characteristics in a registry of multiple myeloma patients using a web-based data analysis.

Low incidence of clinically apparent thromboembolism in Korean patients with multiple myeloma treated with thalidomide

The frequency of thromboembolic events (TE) in Caucasian patients with multiple myeloma (MM) receiving thalidomide as the initial treatment has been reported to be 10~58% without prophylactic anticoagulation. Korean MM patients treated with thalidomide were studied to determine the frequency of TE and associated risk factors. A retrospective medical record review of the Korean MM registry from 25 centers in Korea between 2003 and 2007 was performed. We assessed the incidence of arterial and venous TE and the associated clinical parameters. Three hundred and sixty MM patients (median age 61 years, range 32-88 years) received thalidomide treatment. Fourteen patients (3.9%) developed TE: 12 had venous and two had arterial locations. The sites for the venous TE included lungs (seven), lower extremities (four), upper extremities (one), and neck (one). Arterial TE developed in cerebral and peripheral arteries each. No single clinical parameter such as prerequisite for the metabolic syndrome, disease status, and treatment regimen were predictive for the development of TE. The frequency of TE in patients who received thalidomide as initial therapy (7/155) was not different from those who received thalidomide for progressive or relapsed disease (7/205, p = 0.592). The frequency of TE during thalidomide treatment in Korean patients with MM was low. No significant clinical factor was found to be a risk factor. The subgroup requiring thromboprophylaxis among the Korean patients with MM, receiving thalidomide, needs to be clarified.

A novel translocation t(1;5)(p32;q31) that was not associated with the TAL1 rearrangement in a case of T lymphoblastic leukemia/lymphoma

Chromosome 1 band p32 (1p32) aberrations are common in T lymphoblastic leukemia/lymphoma (T-ALL/LBL). Two types of 1p32 aberrations include translocations with different partners and submicroscopic interstitial deletion. Both aberrations are known to result in TAL1 gene deregulation. The t(1;5)(p32;q31) is a rare translocation of 1p32 in T-ALL. We now present the second case of t(1;5)(p32;q31) in T-ALL, which was present as a primary cytogenetic abnormality, with a review of the relevant literature. Interestingly, neither the translocation of the TAL1 gene nor aberrant expression of TAL1 protein was detected by fluorescent in situ hybridization (FISH) and by immunohistochemical staining in this case.

CD36 signaling inhibits the translation of heat shock protein 70 induced by oxidized low density lipoprotein through activation of peroxisome proliferators-activated receptor gamma

Oxidized LDL (OxLDL), a causal factor in atherosclerosis, induces the expression of heat shock proteins (Hsp) in a variety of cells. In this study, we investigated the role of CD36, an OxLDL receptor, and peroxisome proliferator-activated receptor gamma (PPARgamma) in OxLDL-induced Hsp70 expression. Overexpression of dominant-negative forms of CD36 or knockdown of CD36 by siRNA transfection increased OxLDL-induced Hsp70 protein expression in human monocytic U937 cells, suggesting that CD36 signaling inhibits Hsp70 expression. Similar results were obtained by the inhibition of PPARgamma activity or knockdown of PPARgamma expression. In contrast, overexpression of CD36, which is induced by treatment of MCF-7 cells with troglitazone, decreased Hsp70 protein expression induced by OxLDL. Interestingly, activation of PPARgamma through a synthetic ligand, ciglitazone or troglitazone, decreased the expression levels of Hsp70 protein in OxLDL-treated U937 cells. However, major changes in Hsp70 mRNA levels were not observed. Cycloheximide studies demonstrate that troglitazone attenuates Hsp70 translation but not Hsp70 protein stability. PPARgamma siRNA transfection reversed the inhibitory effects of troglitazone on Hsp70 translation. These results suggest that CD36 signaling may inhibit stress- induced gene expression by suppressing translation via activation of PPARgamma in monocytes. These findings reveal a new molecular basis for the anti-inflammatory effects of PPARgamma.

Effect of short term calorie restriction on pro-inflammatory NF-kB and AP-1 in aged rat kidney

OBJECTIVE

To compare the effect of short-term calorie restriction (CR) on aging with that of already known long-term CR, the anti-inflammatory efficacy of 10-day CR was explored in aged rat kidney.

TREATMENT

Two different age groups, 6 months (young) and 24 months (old) were used. In the old group, one sub-group was control, fed ad libitum (AL) and the other was fed CR for 10 days with 40 % of the food intake of the AL subgroup (n = 5).

METHODS

Reactive species (RS), lipid peroxides and COX-2 activity were measured. The activities of proinflammatory transcription factors NF-kB and AP-1 were measured by electro-mobility shift assay (EMSA). Upstream signaling cascades of NF-kB and AP-1 as well as proinflammatory gene expression were detected by Western blot.

RESULTS

10-day CR suppressed RS, lipid peroxides, and COX-2 activity in aged rat kidney. CR also inhibited upstream signaling cascades and DNA binding activity of NF-kB and AP-1, and thioredoxin/Ref-1 pathway. CR blocked expression of NF-kB-and AP-1-responsive gene COX-2, iNOS, VCAM-1 and ICAM-1.

CONCLUSIONS

We report for the first time that 10-day CR can attenuate the altered signaling transduction for inflammatory processes which is mediated through RS-induced NF-kB and AP-1 in aged kidney.

l-Ascorbic acid 2-phosphate promotes elongation of hair shafts via the secretion of insulin-like growth factor-1 from dermal papilla cells through phosphatidylinositol 3-kinase

BACKGROUND

l-Ascorbic acid 2-phosphate (Asc 2-P), a derivative of l-ascorbic acid, promotes elongation of hair shafts in cultured human hair follicles and induces hair growth in mice.

OBJECTIVES

To investigate whether the promotion of hair growth by Asc 2-P is mediated by insulin-like growth factor-1 (IGF-1) and, if so, to investigate the mechanism of the Asc 2-P-induced IGF-1 expression.

METHODS

Dermal papilla (DP) cells were cultured and IGF-1 level was measured by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay after Asc 2-P treatment in the absence or presence of LY294002, a phosphatidylinositol 3-kinase (PI3K) inhibitor. Also, hair shaft elongation in cultured human scalp hair follicles and proliferation of cocultured keratinocytes were examined after Asc 2-P treatment in the absence or presence of neutralizing antibody against IGF-1. In addition, keratinocyte proliferation in cultured hair follicles after Asc 2-P treatment in the absence or presence of LY294002 was examined by Ki-67 immunostaining.

RESULTS

IGF-1 mRNA in DP cells was upregulated and IGF-1 protein in the conditioned medium of DP cells was significantly increased after treatment with Asc 2-P. Immunohistochemical staining showed that IGF-1 staining is increased in the DP of cultured human hair follicles by Asc 2-P. The neutralizing antibody against IGF-1 significantly suppressed the Asc 2-P-mediated elongation of hair shafts in hair follicle organ culture and significantly attenuated Asc 2-P-induced growth of cocultured keratinocytes. LY294002 significantly attenuated Asc 2-P-inducible IGF-1 expression and proliferation of follicular keratinocytes in cultured hair follicles.

CONCLUSIONS

These data show that Asc 2-P-inducible IGF-1 from DP cells promotes proliferation of follicular keratinocytes and stimulates hair follicle growth in vitro via PI3K.

A prospective, multicenter, phase 2 study of imatinib mesylate in korean patients with metastatic or unresectable gastrointestinal stromal tumor

OBJECTIVES

This prospective, multicenter, phase 2 study evaluated the efficacy and safety of imatinib mesylate and assessed KIT and PDGFRA gene mutation status in Korean patients with gastrointestinal stromal tumors (GISTs).

METHODS

Forty-seven patients with pathologically proven KIT-positive metastatic or unresectable GISTs were accrued from eight institutions in Korea. Imatinib was administered orally at 400 mg once daily. In case of disease progression, the dose was escalated to 600 mg once daily, then 400 mg twice daily. KIT and PDGFRA mutations were analyzed in 29 of the 47 patients.

RESULTS

Imatinib produced partial responses in 30 patients (63.8%; 95% confidence interval, 50.1-77.6%) and stable disease in 13 patients (27.7%). The median time to response was 2.6 months (range, 1.0-6.2 months). With a median follow-up of 62 months (range, 32-67 months), 4-year progression-free survival and overall survival rates were 50 and 65%, respectively. The most common adverse events were anemia, neutropenia, edema, and skin rash (predominantly of grade 1-2). There were no treatment-related deaths. In the subset evaluated for mutational status, 24 patients (82.8%) had KIT exon 11 mutations and 1 (3.4%) had a KIT exon 9 mutation.

CONCLUSIONS

Imatinib is effective and safe in Korean patients with metastatic or unresectable GIST.

Interaction between BCL2 and interleukin-10 gene polymorphisms alter outcomes of diffuse large B-cell lymphoma following rituximab plus CHOP chemotherapy

PURPOSE

Rituximab may overcome bcl-2-mediated chemoresistance through the inhibition of interleukin-10 (IL-10)-mediated loops, thus down-regulating bcl-2 expression. We examined the effects of genetic variation in BCL2/IL10 gene loops on treatment outcomes of diffuse large B-cell lymphoma when treated with either CHOP or rituximab plus CHOP (R-CHOP) chemotherapy.

EXPERIMENTAL DESIGN

Four genotypes were tested including BCL2 -938 C>A (rs2279115), +21 A>G (rs1801018), IL10 -819 T>C (rs1800871), and -592 A>C (rs1800872) in patients receiving either R-CHOP (n = 125) or CHOP (n = 110).

RESULTS

IL10 SNPs, -819 TT/TC or -592 AA/AC genotypes correlated with improved CHOP response rates (P = 0.04). Neither polymorphism separately influenced the failure-free survival (FFS) or overall survival in patients, but the IL10 haplotype was associated with treatment outcomes after R-CHOP for FFS (P = 0.03) or progression (P = 0.007), whereas the -938 AA BCL2 genotype significantly affected overall survival (P = 0.04). An interactive effect between BCL2 and IL10 SNPs was significant in the group with both -938 AA BCL2 genotype and 1 to 2 copies of CC IL10 haplotype. This group showed a better FFS (P = 0.01) and a lower probability of progression (P = 0.004) compared with other genotype groups when treated with R-CHOP chemotherapy.

CONCLUSIONS

These data indicated that R-CHOP chemotherapy resistance in diffuse large B-cell lymphoma may involve interactions between the BCL2 and IL10 genes.

Impact of storage temperature and product pH on the survival of Listeria monocytogenes in vacuum-packaged souse

Souse is a fully cooked, ready-to-eat gelled pork product. There is a zero-tolerance policy for Listeria monocytogenes in ready-to-eat meat products. The survival and/or growth of L. monocytogenes in souse is unknown. The effectiveness of three different souse formulations (pH 4.3, 4.7, and 5.1) for controlling the growth of L. monocytogenes at two refrigerated storage temperatures (5 and 10 degrees C) was evaluated. All products were vacuum packaged. Uninoculated product was prepared as the control, and other products were artificially surface contaminated with a three-strain cocktail of L. monocytogenes (10(6) CFU/ cm2). Microbial counts were obtained on selective and nonselective media twice weekly through 8 weeks of storage. Souse did not support the growth of L. monocytogenes regardless of product formulation or storage temperature. At 5 degrees C, D-values for products with pH values of 4.7 and 5.1 were not different, but survival of L. monocytogenes in product with a lower pH (4.3) was decreased compared with survival in products with higher pH values (P < 0.05). Survival of L. monocytogenes was not impacted by storage temperatures (P > 0.05). Consumer acceptability (n = 75 souse consumers) of pH 4.3 products was not different from that for (typical) pH 4.7 products (P > 0.05). These results indicate that conventionally produced souse does not support the growth of L. monocytogenes and that inactivation of the organism is more likely in products formulated at a lower pH (< or = 4.3) without affecting consumer acceptance.

Effect-site concentration of remifentanil for laryngeal mask airway insertion during target-controlled infusion of propofol

The purpose of this study was to determine the effect-site concentration of remifentanil that would provide optimal conditions for successful laryngeal mask airway insertion during a target-controlled infusion (TCI) of propofol at 3.5 microg.ml(-1) without the use of neuromuscular blockade. Five minutes after propofol infusion, remifentanil was infused at a dose determined by a modified Dixon's up-and-down method. Five minutes after remifentanil infusion, the laryngeal mask was inserted. The effect-site concentration of remifentanil for successful laryngeal mask insertion in 50% of adults (EC(50)) was 3.04 (SD 0.49) ng.ml(-1) during a TCI of 3.5 microg.ml(-1) propofol without neuromuscular blockade. From the probit analysis, the EC(50) and EC(95) of remifentanil were 2.84 ng.ml(-1) (95% CI 2.09-3.57 ng.ml(-1)) and 3.79 ng.ml(-1) (95% CI 3.26-9.25 ng.ml(-1)), respectively.

Effects of activin A on the in vitro development and mRNA expression of bovine embryos cultured in chemically-defined two-step culture medium

The purpose of the present study was to evaluate the effects of activin A on the developmental competence of in vitro fertilized (IVF) bovine embryos derived from a two-step defined culture system (C1/C2 medium) during the early or later stages of embryo development. To evaluate the effects of activin A on transcriptional levels, we analysed genes related to blastocyst hatching and implantation and to activin signalling pathway in IVF embryos. Cumulus-oocyte complexes were matured for 22 h and fertilized in vitro. Presumptive zygotes were cultured in the presence or absence of activin A during early (0-120 h, C1) or later (120-192 h, C2) stages. Although the developmental competence of embryos cultured with activin A in C1 medium was not significantly different from their corresponding controls, development to blastocysts (22.4% vs 34.7%; p < 0.05) and the blastocyst hatching rate (9.3% vs 22.4%; p < 0.05) in C2 medium supplemented with 100 ng/ml activin A were significantly higher than in the control group. To evaluate the effect of activin A on transcription, the relative expression levels of genes related to blastocyst hatching and implantation (Na/K-ATPase, E-cad and Glut-1) as well as activin signalling pathway (ActRII, ActRIIB and Smad2) were analysed. Compared to control medium, gene expression of Na/K-ATPase, E-cad, Glut-1, ActRII and ActRIIB was increased in medium supplemented with activin A. In conclusion, this study suggests that activin A, during the later stage of in vitro bovine embryo development, can enhance in vitro development of embryos by increasing hatching rates and affecting expression levels of genes related to hatching and implantation in defined culture medium.