Abstract P3-11-07: Exploratory biomarker analysis from a phase II, multicenter, randomized trial of eribulin plus gemcitabine(EG) versus paclitaxel plus gemcitabine(PG) as first-line chemotherapy for human epidermal growth factor receptor 2 (HER2)- negative metastatic breast cancer(MBC): Korean cancer study group trial (KCSG BR13-11)

Introduction : A phase II, multicenter, randomized clinical trial of the comparison between eribulin plus gemcitabine (EG) and paclitaxel plus gemcitabine (PG) as first-line chemotherapy for patients with human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) found EG was less neurotoxic, but had similar efficacy of PG. In this study, we performed exploratory biomarker analysis of the impact of genetic alterations on the efficacy according to EG and PG chemotherapy.

Methods : This biomarker study was conducted using tumor samples from 40patients. When tissue collection was possible after disease progression, we performed paired sample analysis. Tumor DNA and RNA were extracted from formalin-fixed, paraffin-embedded tissues. To perform targeted deep sequencing, we used CancerScanTM, a 375 cancer gene panel. And we performed an nCounter expression assay for gene expression analysis using 730 PanCancer panel and 730 Immune panel.

Results: In total, we obtained 44 tissue samples from 40 patients. Twenty two patients were assigned in EG arm and 18 patients were in PG arm. Thirty-eight were at baseline and six after disease progression. Gene expression assay were performed in 44 tissue samples but only 31 samples were possible to be targeted deep sequencing.

We performed differently expressed gene(DEG) analysis for detecting the association between level of gene expression and disease progression. In this analysis, high expression of CCNE1, TGFB4 and BAMBI and low expression of DDB2, CD14 and SHC3 were associated with disease progression among 730 PanCancer panel genes (p<0.05, respectively). In terms of immune panel genes, most of immune related genes were highly expressed in a group without disease progression compared with that with disease progression. Only 2 genes, C8G and CD24 were highly expressed in a group with disease progression. Paired sample analysis showed that expression levels of THBS4 and CD27 decreased after disease progression while those of CCNE2 and FGFR4 increased.

In targeted deep sequencing, FAT3 (42.3%) was most frequently mutated gene followed by PKHD1, PIK3CA and TP53. Among mutated genes, EWSR1 mutation and upstream mutation of ETV1 were associated with disease progression, respectively (p<0.05, respectively). In mutation signature analysis, signature 1 (S, age related), S3(homologous recombination deficiency, HRD), S6 (mismatch repair, MMR), S20(MMR) and S21(microsatellite instability, MSI) were enriched in this population. Mutation signature 3 related to short disease free survival (p=0.0026).

Conclusion: In gene expression analysis, high expression of TGF-B signaling pathway related genes was associated with disease progression while high expression of immune related genes were related to prolonged disease free survival. In mutation analysis, EWSR1 and ETV1 mutations indicated short disease free interval and HRD mutation signature was also related to poor prognosis.

Citation Format: Kim J-Y, Lee EJ, Park KH, Im S-A, Kim S-B, Sohn SH, Lee KS, Chae YS, Lee KH, Kim JH, Im Y-H, Kim T-Y, Lee K-H, Ahn J-H, Kim GM, Park IH, Lee SJ, Han HS, Kim SH, Jung KH, Park YH. Exploratory biomarker analysis from a phase II, multicenter, randomized trial of eribulin plus gemcitabine(EG) versus paclitaxel plus gemcitabine(PG) as first-line chemotherapy for human epidermal growth factor receptor 2 (HER2)- negative metastatic breast cancer(MBC): Korean cancer study group trial (KCSG BR13-11) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-11-07.

Diagnosis of bovine freemartinism by fluorescence in situ hybridization on interphase nuclei using a bovine Y chromosome-specific DNA probe

A heifer co-twin to a bull, in most cases, is a sterile freemartin which needs to be identified and culled from replacement stock. Various methods are available for the diagnosis of freemartinism, but none is ideal in terms of speed, sensitivity, or specificity. The present study was thus conducted to develop and validate a satisfactory fluorescence in situ hybridization procedure on interphase nuclei (I-FISH) for identifying the bovine XX/XY-karyotypic chimerism, the hallmark of freemartinism. A 190-bp DNA FISH probe containing the bovine male-specific BC1.2 DNA sequence was synthesized and labeled with digoxigenin by PCR. The FISH was performed on metaphase spreads and interphase nuclei of blood lymphocytes. Upon FISH, the probe expectedly bound to the nucleus of the male cell or to a region of the p12 locus of the Y chromosome. Twenty-four young heterosexual twins (Holstein-Friesian and Korean Cattle breeds; 10 pairs and 4 singletons) were analyzed in the present study; all but three exhibited the XX/XY-karyotypic chimerism to varying extents in both I-FISH and karyotyping. One heifer was identified to have 100% XX cells by both analyses, whereas two bulls were judged as 100% XY- and XX/XY-chimeric karyotypes by karyotyping and I-FISH, respectively. Nevertheless, the ratios of the XY to XX cells in these animals were very similar between the two analyses. In conclusion, the present I-FISH was a rapid and reliable procedure that can be used for early-life diagnosis of bovine freemartinism.

48 THE AMOUNT OF TELOMERIC DNA IN LYMPHOCYTES OF DOG CLONES

Controversy regarding the restoration of eroded telomere length of donor cells after the nuclear transfer process has arisen from previous studies of cloned cattle, mice, and pigs. Little is known about telomere lengths in dogs from either natural breeding or somatic cell nuclear transfer (SCNT). In this study, we investigated the amount of telomeric DNA (ATD) in the lymphocytes of growing dog clones and their somatic cell donors. One cloned male Afghan hound dog [Snuppy (Lee et al. 2005 Nature 436, 641)] and 3 cloned female Afghan hound dogs (Jang et al. 2006 Theriogenology; doi:10.1016J.THERIOGENOLOGY.2006.11.006) were obtained from somatic cell nuclear transfer (SCNT) of ear skin fibroblasts. The lymphocytes were recovered from all dog clones: their nuclear donor dogs (male donor dog, female donor dog), and six normal Afghan hound dogs (control, and 10-, 20-, 26-, 49-, 55-, and 58-month-old, respectively). The ATD was analyzed by quantitative fluorescence in situ hybridization (Q-FISH) with a telomeric DNA probe. A telomeric probe containing the TTAGGG repeated DNA sequence was simultaneously amplified and labeled with digoxigenin (DIG) by polymerase chain reaction (PCR) using dog genomic DNA as template, a (GGGTAA)7 primer, and a DIG-labeling kit (Roche, Mannheim, Germany). To analyze the amount of telomeric DNA on the lymphocytes, at least 100 interphase nuclei were examined in each specimen. The image was captured by a digital camera (DP-70, Olympus) and analyzed using MetaMorph (Universal Imaging Co., Downingtown, PA, USA), an image analysis program. Our results indicated that the ATD in normal Afghan hounds gradually decreased with age. Although no difference in ATD was observed between 10- and 26-month-old dogs, the ATD in the 26-month-old dog was significantly higher than that in 49-, 55-, and 58-month-olds (P < 0.05). The mean percentage of telomeric DNA in Snuppy (18-month-old; 2.38%) was significantly higher than that in the nuclear donor dog (49-month-old; 2.12%) but less than that in the age-matched control (20-month-old; 2.72%; P < 0.05). The ATD in 3 female clone dogs (3-, 2-, and 2-month-olds; 3.47, 3.28, and 3.07%) were significantly higher than that in the nuclear donor (26-month-old; 2.65%). In conclusion, the mean percentages of telomeric DNA in dog clones were higher than in nuclear donor dogs, and the ATD of the cloned male dog was different from that in age-matched controls from natural reproduction. The results suggest that the amount of telomeric DNA in dog clones can be restored with the nuclear transfer of cultured donor fibroblasts, but further studies are required as to how telomere reprogramming occurs during the nuclear transfer process.

73 RE-CLONING BY SOMATIC CELL NUCLEAR TRANSFER FROM A CLONED KOREAN NATIVE GOAT

Nuclear transfer (NT) is one of the most advanced technologies to increase animal efficiency in livestock production. Re-cloning can be utilized to investigate more effective methods for agricultural, biological, and medical research. However, few studies have been undertaken on re-cloning from cloned animals. The present study was conducted to examine some factors affecting in vitro development of re-cloned embryos and pregnancy by somatic cell nuclear transfer (SCNT). Ear fibroblast cells as karyoplast donors were isolated from a cloned Korean goat, Jinsoonny, 3 weeks after birth and cultured in serum-starvation condition (TCM-199 + 0.5% FBS) for cell confluence. Recipient oocytes were surgically collected by flushing the oviducts at 35 h after hCG injection from FSH-stimulated goats. The zonae pellucidae of the oocytes were partially drilled using a laser system and each somatic cell was individually transferred into an enucleated oocyte. The couplets were electrically fused and activated by ionomycin (5 min) and 6-DMAP (4 h). The reconstructed embryos were cultured in mSOF medium containing 0.8% BSA at 39�C in an atmosphere of 5% CO2, 5% O2, 90% N2 for 12 to 15 h. Re-cloned embryos (2- to 4-cell stages) were surgically transferred into the oviducts of the recipients. Estrous synchronization was induced by 10 days of treatment with a CIDR and a single injection of PGF2�. Pregnancy was diagnosed by progesterone assay and ultrasound on Days 21 and 63 of pregnancy. The fusion and cleavage rates of re-cloned oocytes were 87.5% (182/208) and 56.0% (102/182), respectively. A total of 175 re-cloned embryos were transferred into 28 recipients. Eleven (39.3%) and 4 recipients (14.3%) were confirmed pregnant on Days 21 and 60, respectively. In comparison of pregnany rate by estrous synchronization, a total of 66 and 109 re-cloned embryos were transferred into 11 recipients in natural estrus and 17 recipients in induced estrus, respectively. Five (45.4%) and 2 recipients (18.2%) in natural estrus were confirmed pregnant on Days 21 and 63, while 6 (35.3%) and 2 (11.8%) recipients in induced estrus were pregnant, respectively. There were no differences in pregnancy rate when the recipients were in estrus within 12 h of the donors (40 to 60%). However, the pregnancy rate was significantly decreased when the difference was greater than 24 h (0 to 35%; P &lt;&lt; 0.05). Re-cloning can be used for many purposes, and synchronization between donors and recipients may be an important factor for further success of nuclear transfer.

79 THE AMOUNT OF TELOMERIC DNA IN CLONED CATTLE AND THEIR CALVES IS LESS THAN THAT OF AGE MATCHED CATTLE

A telomere is a structure consisting of tandem repeats sequences of (TTAGGG)n at the end of the eukaryotic chromosome. Telomere lengths in animals vary by species, age, and tissues, as well as environment. This experiment concentrated on the amount of telomeric DNA in cloned cattle, their calves, and age-matched normal cattle. Using somatic cell nuclear transfer (SCNT), we had obtained 16 cloned Korean Native cows derived from ear skin fibroblasts and two cloned bulls from fetal fibroblasts. In addition, four female calves were produced from each cloned cow by artificial insemination. Control cattle selected to have matched age and the same raising place served as counter-parts of cloned the cattle in this study. The lymphocytes of all cloned cattle, their calves, and the age-matched controls were examined for telomere quantity. The amount of telomeric DNA was analyzed by quantitative fluorescence after in situ hybridization (Q-FISH) with a human telomeric DNA repeat probe. A minimum of 100 interphase nuclei from each set of harvests was studied to determine the mean and medium percentages of telomeric DNA using the MetaMorph Imaging System (Universal Imaging Co., West Chester, PA, USA). The amount of telomeric DNA obtained was found to decrease in cloned and control animals during growth. The amounts of telomeric DNA in cloned cattle from both ear skin fibroblasts (n = 16) and fetal fibroblasts (n = 2) was less than that of age-matched controls (P < 0.01). Surprisingly, the amount of telomeric DNA of calves from cloned cattle was also lower than that of age matched controls (n = 4, P < 0.01). The results showed a remarkable difference in the amount of telomeric DNA between SCNT cloned cattle and normal cattle. In conclusion, the telomeres of cloned animal and their calves are significantly shorter than those of normal cattle. Moreover, the short telomeres in calves could be inherited from their cloned mothers.

Role for anti-Müllerian hormone in congenital absence of the uterus and vagina

Molecular genetic techniques were used to determine if mutations in the genes encoding anti-Müllerian hormone (AMH) (also known as Müllerian inhibiting substance (MIS)) and its receptor (AMHR) are commonly present in patients with congenital absence of the uterus and vagina (CAUV). Twenty-two CAUV patients and 96 control subjects from diverse ethnic groups were studied after obtaining informed consent. Genomic DNA samples prepared from leukocytes were digested separately with several different restriction enzymes, and the resultant fragments were analyzed for restriction fragment melting polymorphisms (RFMPs) by denaturing gradient gel electrophoresis (DGGE). Electrophoretic mobility of DNA fragments which were 200-700 base pairs in length was compared using polyacrylamide gels that included linear gradients of denaturing solvents designed to separate DNA fragments according to sequence-dependent variation in thermal stability. Two RFMPs were found in the AMH gene in both patients and normal control subjects. One RFMP in the AMHR gene was present at low frequencies in both patients and normal control subjects. No RFMPs specific to CAUV patients were found in either gene. Because no mutations or rare DNA sequence polymorphisms were detected in the AMH and the AMHR genes in this group of CAUV patients, it is unlikely that either gene commonly has an etiologic role in CAUV.

Crystallization and preliminary X-ray crystallographic analysis of deoxycytidylate hydroxymethylase from bacteriophage T4

Deoxycytidylate hydroxymethylase from bacteriophage T4 is a homodimeric enzyme in which each polypeptide chain consists of 246 amino-acid residues. It has been crystallized in the presence of its substrate, deoxycytidine monophosphate, at room temperature using sodium citrate as precipitant. The crystals are monoclinic, belonging to space group C2, with unit-cell parameters a = 174.22, b = 53.12, c = 75.17 A, beta = 115.29 degrees. The asymmetric unit contains one homodimer, with a corresponding Vm of 2.65 A3 Da-1 and solvent content of 54%. Native diffraction data to 1.6 A resolution have been collected from two crystals using synchrotron radiation.

Crystal structure of deoxycytidylate hydroxymethylase from bacteriophage T4, a component of the deoxyribonucleoside triphosphate-synthesizing complex

Bacteriophage T4 deoxycytidylate hydroxymethylase (EC 2.1.2.8), a homodimer of 246-residue subunits, catalyzes hydroxymethylation of the cytosine base in deoxycytidylate (dCMP) to produce 5-hydroxymethyl-dCMP. It forms part of a phage DNA protection system and appears to function in vivo as a component of a multienzyme complex called deoxyribonucleoside triphosphate (dNTP) synthetase. We have determined its crystal structure in the presence of the substrate dCMP at 1.6 A resolution. The structure reveals a subunit fold and a dimerization pattern in common with thymidylate synthases, despite low (approximately 20%) sequence identity. Among the residues that form the dCMP binding site, those interacting with the sugar and phosphate are arranged in a configuration similar to the deoxyuridylate binding site of thymidylate synthases. However, the residues interacting directly or indirectly with the cytosine base show a more divergent structure and the presumed folate cofactor binding site is more open. Our structure reveals a water molecule properly positioned near C-6 of cytosine to add to the C-7 methylene intermediate during the last step of hydroxymethylation. On the basis of sequence comparison and crystal packing analysis, a hypothetical model for the interaction between T4 deoxycytidylate hydroxymethylase and T4 thymidylate synthase in the dNTP-synthesizing complex has been built.

Administration of progesterone before oocyte retrieval negatively affects the implantation rate

OBJECTIVE

To compare the efficacy of two clinically accepted methods of progesterone supplementation during IVF.

DESIGN

Prospective randomized trial.

SETTING

A university-based IVF program.

PATIENT(S)

Three hundred fourteen stimulated IVF cycles between January 1993 and October 1994.

INTERVENTION(S)

Patients were assigned to one of two luteal phase progesterone regimens by a random permuted block design. In protocol A, 12.5 mg of IM progesterone was given 12 hours before oocyte retrieval; in protocol B, 25 mg of IM progesterone was given on the day of oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy.

RESULT(S)

Patient demographic characteristics, including age, diagnosis, number of oocytes retrieved and fertilized, and number of embryos transferred, were not different between the two groups. There was no difference in the rate of cycle cancellation between the groups. One hundred forty ETs were performed in patients assigned to protocol A and 142 in patients assigned to protocol B. The clinical pregnancy rate in group A was 12.9% compared with 24.6% in group B.

CONCLUSION(S)

The administration of progesterone before oocyte retrieval is associated with a lower pregnancy rate than the administration of progesterone after oocyte retrieval.

Mutation analysis of the gonadotropin-releasing hormone receptor gene in idiopathic hypogonadotropic hypogonadism

OBJECTIVE

To determine if GnRH receptor mutations occur in patients with idiopathic hypogonadotropic hypogonadism.

DESIGN

Patients and controls were studied by molecular genetic analysis.

SETTING

A tertiary medical center setting.

PATIENT(S)

Twenty-four patients with idiopathic hypogonadotropic hypogonadism and 20 controls.

INTERVENTION(S)

Deoxyribonucleic acid from all individuals was analyzed by Southern blot analysis and denaturing gradient gel electrophoresis. Genomic DNA was digested with restriction enzymes, and Southern blots and denaturing gradient gel blots were constructed. Blots were hybridized with the GnRH receptor complementary DNA probe. The DNA sequencing was performed on samples from two representative patients.

MAIN OUTCOME MEASURE(S)

Gonadotropin-releasing hormone receptor gene structure was ascertained by comparing fragments from autoradiographs in patients and controls. Individual nucleotides were ascertained from DNA sequencing gels.

RESULT(S)

No GnRH receptor gene deletions or polymorphisms were identified by Southern blot analysis. New restriction-fragment melting polymorphisms using the enzymes DpnII, RsaI, and HaeIII were identified by denaturing gradient gel blots in patients and controls.

CONCLUSION(S)

Gonadotropin-releasing hormone receptor gene deletions or rearrangements were not observed in our idiopathic hypogonadotropic hypogonadism patients. Denaturing gradient gel electrophoresis failed to identify single-base differences unique to patients with idiopathic hypogonadotropic hypogonadism, dramatically reducing the likelihood that point mutations of the GnRH receptor gene are present in idiopathic hypogonadotropic hypogonadism.

Nonpalpable in situ ductal carcinoma of the breast. Predictors of multicentricity and microinvasion and implications for treatment

Fifty breasts with nonpalpable ductal carcinoma in situ (DCIS) were examined for the presence of microinvasion, multicentricity, and number of involved ducts to see if the biopsy specimen could have predicted the findings in the remainder of the breast. When DCIS was an incidental finding, fewer ducts were involved and no evidence of either microinvasion or multicentricity was found. Solid and cribriform DCIS were rarely multicentric or microinvasive; micropapillary DCIS was often multicentric, rarely microinvasive; comedocarcinoma was more likely to be both microinvasive and multicentric. Ductal carcinoma in situ as an incidental finding may be treated by excision alone; papillary and micropapillary DCIS are best treated by therapy aimed at the entire breast, although axillary dissection may not be required. Therapy for comedocarcinomas should include the entire breast and the axillary nodes.