Clinical practice guidelines for cervical cancer: the Korean Society of Gynecologic Oncology guidelines

This fifth revised version of the Korean Society of Gynecologic Oncology practice guidelines for the management of cervical cancer incorporates recent research findings and changes in treatment strategies based on version 4.0 released in 2020. Each key question was developed by focusing on recent notable insights and crucial contemporary issues in the field of cervical cancer. These questions were evaluated for their significance and impact on the current treatment and were finalized through voting by the development committee. The selected key questions were as follows: the efficacy and safety of immune checkpoint inhibitors as first- or second-line treatment for recurrent or metastatic cervical cancer; the oncologic safety of minimally invasive radical hysterectomy in early stage cervical cancer; the efficacy and safety of adjuvant systemic treatment after concurrent chemoradiotherapy in locally advanced cervical cancer; and the oncologic safety of sentinel lymph node mapping compared to pelvic lymph node dissection. The recommendations, directions, and strengths of this guideline were based on systematic reviews and meta-analyses, and were finally confirmed through public hearings and external reviews. In this study, we describe the revised practice guidelines for the management of cervical cancer.

Enhancing autophagy leads to increased cell death in radiation-treated cervical cancer cells

This study was carried out to determine the effect of autophagy modulation in radiation treatment of cervical cancer cells. HeLa and CaSki cells were irradiated with γ-rays (2 Gy/min) after treatment with an autophagy inducer (rapamycin) and inhibitor (3-MA). Expression of LC3 and cell death in two cell preparations were examined. In addition, expression of Caspase-3 and PARP were examined after radiation alone and with autophagy inhibitor treatment. A notable increment of LC3 expression was detected after radiation in both cell lines. Cell viability was observed to decrease in 3-MA-treated cells compared to radiation alone, and even further in rapamycin-treated cells. Apoptosis was confirmed to occur later than autophagy in radiation treatment, and inhibition of autophagy derived a decrease in apoptosis. In conclusion, radiation-induced autophagy may be regulated by modulators, and autophagy augmentation yields an increase in cervical cancer cell death under radiation.Impact statementWhat is already known on this subject? Autophagy is known to contribute both to tumour cell survival and death against radiation therapy. The effect of induction or inhibition of radiation-induced autophagy on cervical cancer cell death is not clear.What the results of this study add? Cell viability was observed to decrease in 3-MA-treated cells compared to radiation alone, and even further in rapamycin-treated cells. Apoptosis occurred later than autophagy in radiation treatment, and inhibition of autophagy derived a decrease in apoptosis.What the implications are of these findings for clinical practice and/or further research? Our results suggest that radiation-induced autophagy may be regulated by modulators, and autophagy augmentation yields an increase in cervical cancer cell death under radiation.

Ten-year treatment outcomes of consolidation hyperthermic intraperitoneal chemotherapy for ovarian cancer (HIPEC-KOV-03R)

OBJECTIVE

We aimed to evaluate the long-term efficacy of consolidation hyperthermic intraperitoneal chemotherapy (HIPEC) for patients with primary epithelial ovarian cancer.

METHODS

This retrospective cohort study included patients who underwent second-look surgery either with or without HIPEC after having complete or partial response to primary cytoreductive surgery and adjuvant platinum-based chemotherapy between January 1991 and December 2003 at Seoul St. Mary's Hospital. The 10-year progression-free survival (PFS), overall survival (OS), and toxicity within postoperative 28 days were investigated.

RESULTS

A total of 87 patients were identified, 44 (50.6%) received second-look surgery with HIPEC whereas 43 (49.4%) received only second-look surgery. The 10-year PFS and OS were significantly longer in the HIPEC group compared with the control group (PFS, 53.6% vs. 34.9%, log-rank p=0.009; OS, 57.0% vs. 34.5%, log-rank p=0.025). Multivariable analysis identified HIPEC as an independent favorable prognostic factor for PFS (adjusted hazard ratio [HR]=0.42; 95% confidence interval [CI]=0.23-0.77; p=0.005) but not for OS (adjusted HR=0.58; 95% CI=0.32-1.07; p=0.079). The more common adverse events in the HIPEC group were thrombocytopenia (90.9% vs. 68.3%, p=0.005), elevated liver enzymes (65.9% vs. 29.3%, p=0.002), and wound complications (18.2% vs. 2.4%, p=0.032). However, these adverse events were reversible and did not delay subsequent consolidation chemotherapy.

CONCLUSION

The consolidation HIPEC demonstrated a significant improvement in 10-year PFS but not OS, with acceptable toxicity in patients with primary epithelial ovarian cancer. Further randomized controlled trials are warranted to confirm these results.

Risk factors for the failure of first-line PARP inhibitor maintenance therapy in patients with advanced ovarian cancer: Gynecologic Oncology Research Investigators Collaboration Study (GORILLA-3004)

OBJECTIVE

To identify the risk factors for failure of first-line poly (ADP-ribose) polymerase inhibitor (PARPi) maintenance therapy in patients with advanced ovarian cancer.

METHOD

Patients with stage III-IV epithelial ovarian cancer who received first-line PARPi maintenance therapy were retrospectively reviewed. Clinicopathologic factors were compared between two groups-recur/progression of disease (PD) and non-recur/PD.

RESULTS

In total, 191 patients were included. Median follow-up was 9.9 months, and recurrence rate was 20.9%. BRCA mutations were found in 63.4% patients. Postoperative residual tumor (60.5% vs. 37.8%), non-high grade serous carcinoma (HGSC) (15.0% vs. 6.0%), neoadjuvant chemotherapy (NAC) (55.0% vs. 35.8%), and pre-PARPi serum CA-125 levels ≥23.5 U/mL (35.9% vs. 15.2%) were more frequently observed in the recur/PD group. Multivariate Cox-regression analysis revealed pre-PARPi serum CA-125 levels ≥23.5 U/mL (HR, 2.17; 95%CI, 1.03-4.57; p = 0.042), non-HGSC (3.28; 1.20-8.97; p = 0.021), NAC (2.11; 1.04-4.26; p = 0.037), and no BRCA mutation (2.23; 1.12-4.44; p = 0.023) as independent risk factors associated with poor progression-free survival (PFS). A subgroup analysis according to BRCA mutation status showed that pre-PARPi serum CA-125 levels ≥26.4 U/mL were the only independent risk factor for poor PFS in women with BRCA mutations (2.75; 1.03-7.39; p = 0.044). Non-HGSC (5.05; 1.80-14.18; p = 0.002) and NAC (3.36; 1.25-9.04; p = 0.016) were independent risk factors in women without BRCA mutations.

CONCLUSION

High pre-PARPi serum CA-125 levels, non-HGSC histology, NAC, and no BRCA mutation might be risk factors for early failure of first-line PARPi maintenance therapy. In women with BRCA mutations, high pre-PARPi serum CA-125 levels, which represent a large tumor burden before PARPi, were the only independent risk factor for poor PFS.

Is minimally invasive radical surgery safe for patients with cervical cancer ≤2 cm in size? (MISAFE): Gynecologic Oncology Research Investigators coLLborAtion study (GORILLA-1003)

OBJECTIVE

To identify clinicopathological factors associated with disease recurrence for patients with 2018 FIGO stage IA with lymphovascular invasion to IB1 cervical cancer treated with minimally invasive surgery (MIS).

METHODS

A total of 722 patients with cervical cancer between January 2010 and February 2021 were identified. Clinicopathological factors related to disease recurrence were analyzed. Disease-free survival (DFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method. To determine prognostic factors for DFS, a Cox proportional hazard regression model was used.

RESULTS

Of 722 patients, 49 (6.8%) experienced disease recurrence (37 pelvis, 1 para-aortic lymph node, and 11 peritoneum). Five-year DFS and OS rates were 90.7% and 98.1%, respectively. In multivariate analysis, risk factors associated with disease recurrence were residual disease in the remaining cervix (OR, 3.122; 95% CI, 1.152-8.461; p = 0.025), intracorporeal colpotomy (OR, 3.252; 95% CI, 1.507-7.017; p = 0.003), and positive resection margin (OR, 3.078; 95% CI, 1.031-9.193; p = 0.044). The non-conization group had a higher percentage of stage IB1 (77.4% vs. 64.6%; p = 0.004) and larger tumor (10 mm vs. 7 mm; p < 0.001) than the conization group. Intracorporeal colpotomy and residual disease in the remaining cervix were independent variables associated with disease recurrence in patients undergoing MIS following conization.

CONCLUSION

During MIS, patients with cervical cancer ≤2 cm in size can be vulnerable to peritoneal recurrences. Patients diagnosed with invasive cancer through conization often have low-risk pathological features, which may affect their survival outcomes.

Fertility-sparing hormonal treatment in patients with stage I endometrial cancer of grade 2 without myometrial invasion and grade 1-2 with superficial myometrial invasion: Gynecologic Oncology Research Investigators coLLaborAtion study (GORILLA-2001)

OBJECTIVES

To evaluate oncologic and pregnancy outcomes of fertility-sparing treatment (FST) using progestin in patients with stage I grade 2 endometrioid endometrial cancer (EC) without myometrial invasion (MI) or grade 1-2 with superficial MI.

METHODS

Multicenter data of patients with stage I grade 2 EC without MI or grade 1-2 EC with superficial MI, who received FST between 2005 and 2021, were analyzed. Cox regression analysis identified independent factors for progressive disease (PD) during the FST.

RESULTS

Altogether, 54 patients received FST [medroxyprogesterone acetate (500-1000 mg) in 44, megestrol acetate (40-800 mg) in 10] with concurrent levonorgestrel-releasing intrauterine devices use in 31. With median time to achieve a complete response (CR) of 10 (3-24) months, 39 patients (72.2%) achieved CR. Of the 15 patients who attempted to conceive after achieving CR, 7 (46.7%) became pregnant (2 abortions, 5 live births). During a median FST duration of 6 (3-12) months, nine patients (16.6%) were diagnosed with PD. Fifteen (38.5%) experienced recurrence with a median recurrence-free survival of 23 (3-101) months. In the multivariable analysis, tumor size before FST ≥2 cm (HR 5.456, 95% CI 1.34 to 22.14; p = 0.018) was significantly associated with a high PD rate during FST.

CONCLUSION

The overall response rate to FST was promising, however, the PD rate was significant during the first 12 months of FST. Therefore, performing thorough endometrial biopsy and imaging studies is essential to strictly evaluate the extent of the disease every 3 months from FST initiation.

Robot-assisted versus conventional laparoscopic radical hysterectomy in cervical cancer stage IB1

Objective: The aim of this study was to compare survival outcomes of robot-assisted laparoscopic radical hysterectomy (RRH) and conventional laparoscopic radical hysterectomy (LRH) in cervical cancer stage IB1. Method: This is a retrospective study of patients with cervical cancer stage IB1 who surgically treated by either RRH or LRH. Oncologic outcomes of the patients were compared according to surgical approach. Results: In total, 66 and 29 patients were assigned to LRH and RRH groups. All patients had stage IB1 disease (FIGO 2018). Intermediate risk factors (tumor size, LVSI, and deep stromal invasion), proportion of patients receiving adjuvant therapy (30.3% vs. 13.8%, p = 0.09), and median follow-up time (LRH, 61 months; RRH, 50 months; p=0.085) did not differ significantly between the two groups. The recurrence rate was higher in the LRH group; however, there was no significant difference between the two groups (p=0.250). DFS (55.4 vs 48.2 months, p = 0.250), and OS (61.2 vs 50.0 months, p = 0.287) were similar between the LRH and RRH groups. Conclusion: In patients with a tumor size < 2 cm, the recurrence rate was lower in RRH group; however, there was no significant difference. Further large-scale RCTs and clinical studies are required to provide relevant data.

Usefulness of Short-Term Imaging and Squamous Cell Carcinoma Antigen to Early Predict Response to Concurrent Chemoradiotherapy in Patients With Cervical Cancer

OBJECTIVE

The objective is to investigate the factors that can predict early treatment response in patients receiving concurrent chemoradiotherapy (CCRT) for cervical cancer.

METHODS

We assessed clinical factors and treatment response in patients who underwent CCRT for cervical cancer at four time points: initial, 2.5 weeks, 6 weeks after starting CCRT, and 3 months after completing CCRT. The final treatment response was determined by positron emission tomography-computed tomography (PET-CT) 3 months after completion of CCRT. Patients were divided into two groups according to the final treatment response: complete response (CR) group or non-CR group. And the early CCRT response prediction model was developed using stepwise multivariate logistic regression analysis.

RESULTS

Of the 62 patients who underwent CCRT for cervical cancer, 57 patients who completed all 4 time points examinations were included in the analyses and classified as CR (n = 32) and non-CR (n = 25) group. Tumor volume and serum squamous cell carcinoma antigen (SCC Ag) of the initial, 2.5 weeks, and 6 weeks after CCRT were significantly associated with the final treatment response. For the early treatment response prediction model, we selected patient age, tumor volume, and SCC Ag measured at initial and 2.5 weeks of CCRT as variables, and the equation of the final model was yielded. Using a cutoff of 0.433, this model had a sensitivity of 72.0%, a specificity of 84.4%, and a probability of 0.8225 (P < .0001).

CONCLUSION

Short-term (at 2.5 weeks after starting CCRT) measurements of tumor volume and serum SCC Ag were significant predictors of response to CCRT in patients with cervical cancer.

Prognostic significance of histological grade in low-risk endometrial cancer

Objective: Investigate the risk factors for recurrence in patients with low-risk endometrial cancer. Method: A retrospective review was performed to identify patients who underwent primary surgical treatment for endometrial cancer from December 2009 to December 2020. Patients who met the following criteria were included in the study: (a) International Federation of Gynecology and Obstetrics stage IA, (b) endometrioid-type histology, (c) histological grade 1 or 2. Univariate and multivariate analyses using Cox proportional hazards model to evaluate effects of prognostic factors. Disease-free survival and overall survival were calculated using the Kaplan-Meier method. Results: A total of 171 patients with low-risk endometrial cancer were included in the study. Recurrence was detected in 9 patients. Histological grade was found to be independent risk factors for recurrence in women with low-risk endometrial cancer (OR 8.255, 95% confidence interval (CI) 1.585 - 42.981; p = 0.012). Conclusion: The results of this study suggest that grade 2 disease should be considered a significant prognostic factor for the recurrence of low-risk endometrial cancer.

Postoperative Adjuvant Chemoradiotherapy Versus Chemotherapy Alone for Stage III Endometrial Cancer: A Multicenter Retrospective Study

Introduction

We aimed to evaluate the efficacy and toxicity of the combination of 6 cycles of chemotherapy and radiation therapy compared with chemotherapy alone as postoperative adjuvant therapy for patients with stage III endometrial cancer.

Methods

This retrospective cohort study included patients with stage III endometrial cancer who received postoperative chemoradiotherapy or chemotherapy alone at 6 hospitals between January 2009 and December 2019. The progression-free survival (PFS) and overall survival (OS) for each treatment group were analyzed using the Kaplan–Meier method. We also assessed differences in toxicity profiles between the treatment groups.

Results

A total of 133 patients met the inclusion criteria. Of these, 80 patients (60.2%) received adjuvant chemoradiotherapy and 53 (39.8%) received chemotherapy alone. The PFS and OS did not differ significantly between the groups. For patients with stage IIIC endometrioid subtype, the chemoradiotherapy group had significantly longer PFS rate than did the chemotherapy alone group (log-rank test, P = .019), although there was no significant difference in the OS (log-rank test, P = .100). CRT was identified as a favorable prognostic factor for PFS in multivariate analysis (adjusted HR, .37; 95% CI, .16-.87; P = .022). Patients treated with chemoradiotherapy more frequently suffered from grade 4 neutropenia (73.8% vs 52.8%; P = .018) and grade 3 or worse thrombocytopenia (36.3% vs 9.4%; P = .001) compared with the chemotherapy alone group. There were no differences between the 2 treatment groups in the frequency of toxicity-related treatment discontinuation or dose reduction.

Conclusion

We confirmed that chemoradiotherapy yields longer progression-free survival than does chemotherapy alone for patients with stage IIIC endometrioid endometrial cancer, with an acceptable toxicity profile.

Oncologic safety of minimally invasive surgery in non-endometrioid endometrial cancer

OBJECTIVE

This study was aimed to compare the oncologic outcomes of patients with non-endometrioid endometrial cancer who underwent minimally invasive surgery with the outcomes of patients who underwent open surgery.

METHOD

This is a retrospective, multi-institutional study of patients with non-endometrioid endometrial cancer who were surgically staged by either minimally invasive surgery or open surgery. Oncologic outcomes of the patients were compared according to surgical approach.

RESULTS

113 patients met the inclusion and exclusion criteria. 57 underwent minimally invasive surgery and 56 underwent open surgery. Patients who underwent minimally invasive surgery had smaller tumors (median size, 3.3 vs. 5.2%, p = 0.0001) and a lower lymphovascular space invasion rate (29.8% vs. 48.2%, p = 0.045). In the overall population, the numbers and rate of recurrence were significantly higher in the open surgery group (p = 0.016). In multivariate analysis, disease stage and tumor size were associated with DFS in contrast to surgical procedure.

CONCLUSION

Minimally invasive surgery showed similar survival outcomes when compared to open surgery in non-endometrioid endometrial cancer patients, irrespective of disease stage. When minimally invasive surgery is managed by expert surgeons, non-endometrioid histological subtypes should not be considered a contraindication for minimally invasive surgery.

Minimally invasive surgery for patients with advanced stage endometrial cancer

Objective: Compare the oncologic outcomes of patients with advanced stage endometrial cancer who were staged by minimally invasive surgery with the outcomes of patients who underwent open surgery. Methods: Data from 138 patients with advanced stage endometrial cancer who were treated between January 2009 and January 2019 were reviewed. The patients' data were retrieved from five institutions. The patients were divided into two groups: those who underwent open surgery and those who underwent minimally invasive surgery. Tumor characteristics, recurrence rate, disease-free survival, and overall survival were compared according to surgical approach. Results: Among the 138 patients included in this study, 72 underwent open surgery (52.2%) and 66 underwent MIS (47.8%). In patients with advanced-stage endometrial cancer, the recurrence rate was significantly higher among those who underwent open surgery (43.1% vs. 25.8%, p = 0.033). Patients with advanced-stage endometrial cancer who underwent open surgery had a significantly lower disease-free survival (p = 0.029) than those who underwent minimally invasive surgery, however, the overall survival (p = 0.051) was similar between the two groups. Conclusion: Minimally invasive surgery showed better survival outcomes when compared to open surgery in advanced-stage EC patients irrespective of the histologic type.

Preoperative neutrophil-to-lymphocyte, platelet-to-lymphocyte and monocyte-to-lymphocyte ratio as a prognostic factor in non-endometrioid endometrial cancer

Objective: Evaluate the prognostic value of neutrophil-lymphocyte ratio (NMR), platelet-lymphocyte ratio (PLR), and monocyte-lymphocyte ratio (MLR) in patients with non-endometrioid endometrial cancer. Method: Laboratory and clinicopathological data from 118 patients with non-endometrioid endometrial cancer who underwent surgical resection between January 2010 and December 2019 were reviewed. NLR, PLR and MLR were analyzed for correlations with recurrence and survival. The receiver operating characteristic (ROC) curves were generated for the NLR, PLR, and MLR. Optimal cut-off values were determined as the points at which the Youden index (sensitivity + specificity - 1) was maximal. Based on the results of the ROC curve analysis, the patients were grouped into high MLR and low MLR groups. Recurrence rate, disease-free survival, and overall survival were compared between the two groups. The prognostic factors were investigated using univariate and multivariate Cox proportional hazards model. Results: The optimal cut-off value of MLR was 0.191 (AUC, 0.718; p < 0.001). Significantly more patients in the high MLR group experienced recurrence (60.3% vs. 15.6%, p < 0.0001) and cancer-related deaths (46.6% vs. 13.3%, p = 0.003). In multivariate analysis, advanced stage and high MLR were independent prognostic factors for disease-free survival and overall survival. Conclusion: Elevated MLR was significantly associated poor clinical outcomes in patients with non endometrioid endometrial cancer. Our findings suggest that MLR may be clinically reliable and useful as an independent prognostic marker for patients with non-endometrioid endometrial cancer.

Prediction of lymphovascular space invasion in patients with endometrial cancer

Objective: Predict the presence of lymphovascular space invasion (LVSI), using uterine factors such as tumor diameter (TD), grade, and depth of myometrial invasion (MMI). Develop a predictive model that could serve as a marker of LVSI in women with endometrial cancer (EC). Methods: Data from 888 patients with endometrioid EC who were treated between January 2009 and December 2018 were reviewed. The patients' data were retrieved from six institutions. We assessed the differences in the clinicopathological characteristics between patients with and without LVSI. We performed logistic regression analysis to determine which clinicopathological characteristics were the risk factors for positive LVSI status and to estimate the odds ratio (OR) for each covariate. Using the risk factors and OR identified through this process, we created a model that could predict LVSI and analyzed it further using receiver operating characteristic curve analysis. Results: In multivariate logistic regression analysis, tumor size (P = 0.027), percentage of MMI (P < 0.001), and presence of cervical stromal invasion (P = 0.002) were identified as the risk factors for LVSI. Based on the results of multivariate logistic regression analysis, we developed a simplified LVSI prediction model for clinical use. We defined the "LVSI index" as "TD×%MMI×tumor grade×cervical stromal involvement." The area under curve was 0.839 (95% CI= 0.809-0.869; sensitivity, 74.1%; specificity, 80.5%; negative predictive value, 47.3%; positive predictive value, 8.6%; P < 0.001), and the optimal cut-off value was 200. Conclusion: Using the modified risk index of LVSI, it is possible to predict the presence of LVSI in women with endometrioid endometrial cancer. Our prediction model may be an appropriate tool for integration into the clinical decision-making process when assessed either preoperatively or intraoperatively.

Surgical outcomes of single port lapraroscopic radical hysterectomy in cervical cancer

e17003

Background: We aim to see the postoperative outcomes of single port laparoscopic radical hysterectomy in cervical cancer. Methods: Twenty five cervical cancer patients (FIGO stage 9 IA, 13 IB, and 3 IIA) were treated by single port laparoscopic radical hysterectomy in single center. Results: Six patients were performed by type A hysterectomy, 6 by type B, and 13 by type C radical hysterectomy. Median operation time was 91, 197, and 275 minutes, respectively. Median number of pelvic nodes retrieved was 20. There was no postoperative complication except a colon serosa injury in type C radical hysterectomy and which repaired by single port approach. Ten out of 25 patients got an adjuvant radiation therapy and there were 3 recurrences (1 in type A, 2 in type C). Median disease free survival was 9.5 months in type A, 14 months in type C. Conclusions: Single port radical hysterectomy is safe and comparable to conventional laparoscopic hysterectomy in cervical cancer

Influence of epidermal growth factor supplementation during in vitro maturation on nuclear status and gene expression of canine oocytes

This study evaluated the effect of epidermal growth factor (EGF) supplementation during in vitro maturation on the meiotic status and the expression of EGF receptor (EGFr), luteinizing hormone receptor (LHr) and gap junction protein α 5 (GJA5) in canine cumulus-oocyte-complexes (COCs). COCs of ≥110 μm diameter, exhibiting dark pigmentation and completely surrounded by three or more layers of cumulus cells collected from anestrus stage ovaries in natural cycle were matured in TCM-199 supplemented with 10% fetal bovine serum, 0.57 mM cysteine, 10 μg/ml LH and FSH, and different concentrations of EGF (0, 10 and 30 ng/ml). Oocytes cultured for 72 h were fixed to assess the nuclear maturation. Expression of EGFr, LHr and GAJ5 was assessed by immunocytochemistry and real-time PCR. Proportion of metaphase II status of oocytes cultured in in vitro maturation (IVM) medium supplemented with 10 ng/ml EGF for 72 h was significantly (P<0.05) higher than 0 and 30 ng/ml EGF supplemented IVM medium (9.8% vs. 6.5% and 5.2%). In both cumulus cells and oocytes, EGFr protein was undetectable, LHr protein level of expression was low and a strong expression of GJA5 protein was observed. The relative abundance (RA) of EGFr transcript revealed low levels and the LHr expression decreased steadily with addition of EGF. However it did not vary among different concentrations of EGF supplementation. The RA of GJA5 transcript exhibited lower level at 10 ng/ml EGF supplementation. In conclusion, the supplementation of 10 ng/ml EGF in IVM media exerted a positive influence on the progression of maturation to MII phase and the expression level of GJA5 at 72 h, but did not demonstrate any stimulatory role on the expression of EGFr and LHr during the maturation of the canine IVM oocytes.

Expression pattern of oxygen and stress-responsive gene transcripts at various developmental stages of in vitro and in vivo preimplantation bovine embryos

The present study examined the expression pattern of oxygen (O(2)) and stress-responsive gene transcripts at various preimplantation developmental stages of in vitro produced (IVP) and in vivo derived (IVD) bovine embryos. Embryos were produced in vitro from oocytes matured, fertilized and cultured in synthetic oviductal fluid (SOF) medium under low (5%) and high (20%) O(2) concentrations. In vivo embryos were derived from 18 superovulated and artificially inseminated cows. In IVP and IVD groups, embryos were collected at 2-, 4-, 8-, 16-cell morula and blastocyst stages at specific time points for gene expression analysis. The cleavage rates (69.8+/-4.8%) did not differ significantly, but blastocyst rates were significantly higher (28.5+/-3.7%) in low O(2) than those in high O(2) group (18.7+/-3.9%). Mean cell number in low O(2) (145+/-12) and high O(2) (121+/-73) IVP blastocyst were lower (P<0.05) than those of IVD blastocyst (223+/-25). The ICM ratio of IVD blastocyst (26+/-4) was lower (P<0.05) than that of IVP embryos under 5% O(2) (33+/-5) and 20% O(2) (34+/-4) concentrations, respectively. Using real time PCR, for the set of target transcripts (Glut1, Glut5, Sox, G6PD, MnSOD, PRDX5, NADH and Hsp 70.1) analyzed, there were differences in the mRNA expression pattern at 2-, 4-, 8-, 16-cell morula and Day 7 blastocyst stages between the two embryo sources. It can be concluded that, although in vitro bovine embryo culture in SOF medium under low (5%) O(2) concentration provided a more conducive environment in terms of blastocyst formation; differences in the total cell number and gene expression pattern between the IVP and IVD embryos reflected the effect of O(2) concentration.

Effects of Confluent, Roscovitine Treatment and Serum Starvation on the Cell-cycle Synchronization of Bovine Foetal Fibroblasts

The present study was designed to examine the effects of cell-cycle synchronization protocols, such as confluent, roscovitine treatment and serum starvation, in bovine foetal fibroblasts on synchronization accuracy at G0/G1, viability, apoptosis, necrosis and ploidy for use as a nuclei donor. The cells in 5-10 passages were randomly allocated into three treated groups. Cells were cultured either in Dulbecco's modified Eagle's medium (DMEM) + 10% foetal bovine serum (FBS) until 90% confluent (group 1, confluent), in DMEM + 10% FBS + 30 microM roscovitine for 12 h (group 2, roscovitine), or in DMEM + 0.5% FBS for 5 days (group 3, serum starvation). Most of the cells (>80%) in all groups were arrested at the G0/G1 stage. Although the rates did not differ, cells in group 1 showed an increased cell population arrested at the G0/G1 phase. Significantly (p < 0.05) higher rates of apoptosis occurred in group 3 than in group 1 and 2 (10% vs 6% and 6%, respectively). No differences in chromosomal abnormality were observed among groups. However, by increasing the number of cell culture passages up to 15, significantly (p < 0.05) higher chromosomal abnormality was observed than in 5 and 10 passages (39% vs 28% and 23%, respectively) in group 1. The results clearly indicated that bovine foetal fibroblasts could be effectively synchronized at G0/G1 stages by all the three different treatments, confluent, roscovitine and serum starvation. However, cells in confluent showed reduced apoptosis and necrosis when they underwent 5-10 passages, exhibiting increased percentage of cells with stable chromosome diversity. Hence, cells in confluent merit further studies before they could be used as nuclear donors.

Efficient Production of Cloned Bovine Embryos Using cdc2 kinase Inhibitor

This study was carried out to compare the effects of the combination of ionomycin with a H1-histone kinase inhibitor (dimethylaminopurine, DMAP) or cdc2 kinase inhibitor (sodium pyrophosphate, SPP) on the development of reconstituted bovine eggs. For this study, the enucleated bovine oocytes were injected with a presumptive primordial germ cell pre-treated with 1% sodium citrate, and randomly allocated into three activation groups: Group 1 (ionomycin 5 microm, 5 min), Group 2 (ionomycin + DMAP 1.9 mm, 3 h), and Group 3 (ionomycin + SPP 2 mm, 3 h). The reconstituted eggs were compared on the rates of cleavage and development with the blastocyst stage and the ploidy of embryos at 96 h post-activation. Cleavage rates and blastocyst development in Groups 1, 2 and 3 were 7 and 0%, 63 and 17%, and 53 and 14%, respectively. The chromosomal composition differed significantly (p < 0.05) among treatments. Although the embryos in Group 1 had significantly lower developments, 60% of embryos evaluated had diploid chromosomal sets. In contrast, approximately 60% of embryos in Group 2 had abnormal ploidy (21% polyploid and 38% mixoploid). In Group 3, the appearance of abnormal chromosome sets was reduced with the proportion of diploid embryos being increased to 86% (19 of 22), significantly higher (p < 0.05) than in Group 2. It can be concluded that the use of SPP with ionomycin reduces greatly the incidence of chromosomal abnormalities, and may be applicable for the activation of nuclear transplant bovine embryos.

Analysis of the cbbF genes from Alcaligenes eutrophus that encode fructose-1,6-/sedoheptulose-1,7-bisphosphatase

The cbbF genes of the facultative chemoautotroph Alcaligenes eutrophus H16 are part of two highly homologous cbb operons. Both the chromosomal and the megaplasmid pHG1-borne copy of cbbF were cloned and sequenced. Subsequent analyses including comparison with known sequences from other organisms and heterologous expression in Escherichia coli revealed that each of the genes encodes fructose-1,6-bisphosphatase (FBPase). A closely related activity likewise operating in the Calvin carbon reduction cycle, sedoheptulose-1,7-bisphosphatase, was also catalyzed by the two isoenzymes which were purified from autotrophically grown cells of A. eutrophus. Two-dimensional gel electrophoresis allowed the separation of the cbbF gene products. Preliminary physical evidence by Southern hybridization with a heterologous gene probe was obtained for the existence of a third FBPase gene, fbp, on the chromosome of the organism. Its product is probably involved in the heterotrophic carbon metabolism.

Analysis of the genes forming the distal parts of the two cbb CO2 fixation operons from Alcaligenes eutrophus

In the facultative chemoautotroph Alcaligenes eutrophus H16, most of the genes (cbb genes) encoding enzymes of the Calvin carbon reduction cycle are organized within two highly homologous cbb operons, one located on the chromosome and the other on the megaplasmid pHG1. Nucleotide sequencing of the promoter-distal part of the operons revealed three open reading frames, designated cbbG, cbbK, and cbbA. Similarity searches in databases and heterologous expressions of the subcloned genes in Escherichia coli identified them as genes encoding the Calvin cycle enzymes glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase, and a class II fructose-1,6-bisphosphate aldolase, respectively. The aldolase could be grouped together with the enzymes from Rhodobacter sphaeroides and Bacillus subtilis as a new subtype of class II aldolases. A phenotypic complementation analysis with a cbb operon mutant of A. eutrophus showed that the cbbG product is essential for autotrophic growth of the organism, whereas the products of cbbK and cbbA can apparently be substituted by isoenzymes encoded elsewhere on the chromosome. No or only low constitutive promoter activity was associated with cbbK and cbbA, respectively, confirming the two genes as parts of the cbb operon. Downstream of cbbA, the very high overall nucleotide sequence identity (about 94%) prevailing throughout the two cbb operons discontinues, suggesting that cbbA is the most promoter-distal gene of the operon.

The cbb operons of the facultative chemoautotroph Alcaligenes eutrophus encode phosphoglycolate phosphatase

The two highly homologous cbb operons of Alcaligenes eutrophus H16 that are located on the chromosome and on megaplasmid pHG1 contain genes encoding several enzymes of the Calvin carbon reduction cycle. Sequence analysis of a region from the promoter-distal part revealed two open reading frames, designated cbbT and cbbZ, at equivalent positions within the operons. Comparisons with known sequences suggested cbbT to encode transketolase (TK; EC 2.2.1.1) as an additional enzyme of the cycle. No significant overall sequence similarities were observed for cbbZ. Although both regions exhibited very high nucleotide identities, 93% (cbbZ) and 96% (cbbT), only the chromosomally encoded genes were heterologously expressed to high levels in Escherichia coli. The molecular masses of the observed gene products, CbbT (74 kDa) and CbbZ (24 kDa), correlated well with the values calculated on the basis of the sequence information. TK activities were strongly elevated in E. coli clones expressing cbbT, confirming the identity of the gene. Strains of E. coli harboring the chromosomal cbbZ gene showed high levels of activity of 2-phosphoglycolate phosphatase (PGP; EC 3.1.3.18), a key enzyme of glycolate metabolism in autotrophic organisms that is not present in wild-type E. coli. Derepression of the cbb operons during autotrophic growth resulted in considerably increased levels of TK activity and the appearance of PGP activity in A. eutrophus, although the pHG1-encoded cbbZ gene was apparently not expressed. To our knowledge, this study represents the first cloning and sequencing of a PGP gene from any organism.

The Calvin cycle enzyme pentose-5-phosphate 3-epimerase is encoded within the cfx operons of the chemoautotroph Alcaligenes eutrophus

Several genes (cfx genes) encoding Calvin cycle enzymes in Alcaligenes eutrophus are organized in two highly homologous operons comprising at least 11 kb. One cfx operon is located on the chromosome; the other is located on megaplasmid pHG1 of the organism (B. Bowien, U. Windhövel, J.-G. Yoo, R. Bednarski, and B. Kusian, FEMS Microbiol. Rev. 87:445-450, 1990). Corresponding regions of about 2.7 kb from within the operons were sequenced. Three open reading frames, designated cfxX (954 bp), cfxY (765 bp), and cfxE (726 bp), were detected at equivalent positions in the two sequences. The nucleotide identity of the sequences amounted to 94%. Heterologous expression of the subcloned pHG1-encoded open reading frames in Escherichia coli suggested that they were functional genes. The observed sizes of the gene products CfxX (35 kDa), CfxY (27 kDa), and CfxE (25.5 kDa) closely corresponded to the values calculated on the basis of the sequence information. E. coli clones harboring the cfxE gene showed up to about 19-fold-higher activities of pentose-5-phosphate 3-epimerase (PPE; EC 5.1.3.1) than did reference clones, suggesting that cfxE encodes PPE, another Calvin cycle enzyme. These data agree with the finding that in A. eutrophus, PPE activity is significantly enhanced under autotrophic growth conditions which lead to a derepression of the cfx operons. No functions could be assigned to CfxX and CfxY.