Perioperative risk and benefit of antiplatelet therapy in patients undergoing non-cardiac surgery within 1 year after percutaneous coronary intervention with second-generation drug-eluting stents

Background

Antiplatelet therapy (APT) in patients undergoing non-cardiac surgery (NCS) after percutaneous coronary intervention (PCI) is still on debate due to its opposite effects which are to prevent from cardiovascular events and to cause bleeding. There is no apparent consensus on how to determine perioperative APT strategy within 1 year after PCI. Therefore, we investigated the risk and benefit of APT in NCS within 1 year after PCI.

Methods

Patients undergoing NCS after PCI with second-generation drug-eluting stents are retrospectively included from multicenter cohort of 8 medical centers in Korea. Perioperative clinical event within 30 days after NCS was recorded. Net adverse clinical event (NACE) including all cause death, major adverse cardiac event (MACE, a composite of cardiac death, myocardial infarction, and stent thrombosis) and major bleeding were evaluated. To overcome bias, propensity score covariate adjustment was performed using logistic regression analysis to generate propensity scores for patients of both APT strategies.

Results

Total 1130 patients (median age 69 years, female 30.5%) undergoing NCS within 1 year after PCI were eligible in the cohort. Study population included 55.1% patients suffered from ACS and 22.5% underwent complex PCI. NCS included 45.8% intermediate-to-high risk surgery and 10.7% urgent or emergent surgery. APT was continued during NCS in 62.7% of the patients. More patients continued DAPT (48% vs. 32%, p<0.001) among the patients who underwent NCS within 6 months after PCI than those who underwent NCS after 6 months. There were 49 NACE (4.3%), 16 MACE (1.4%) and 23 major bleeding events (2.0%), respectively. Continuing APT was associated with a lower risk of NACE (Adjusted hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.27–0.89; p=0.020)) and MACE (Adjusted HR, 0.35; 95 CI, 0.12–0.96; p=0.042). Subgroup analysis showed a tendency that continuing APT might be favorable than discontinuing APT in terms of MACE in patients who were diagnosed with ACS, underwent complex PCI, or underwent NCS within 6 months after PCI.

Conclusions

About two thirds of the patients were continuing APT during NCS. Our findings may support a careful consideration of APT continuation for some of the patients who are undergoing NCS within 1 year after PCI.

Funding Acknowledgement

Type of funding sources: None.

Abstract OT2-05-02: International retrospective cohort study of locoregional and systemic therapy in oligometastatic breast cancer (OLIGO-BC1)

Breast cancer (BC) is so-called “systemic disease”, because disseminated cancer cells in bone marrow and blood are detected even in early BC patients. Despite adjuvant therapy and postoperative radiation therapy, patients with triple negative BC and Luminal B-like BC often relapse early and systemic therapy is the only way to control disease progression. On the other hand, some BC patients relapse several years later. In such patients, oligometastases are occasionally diagnosed, because metastatic cancer cells are slowly growing and indolent. Oligometastatic BC is defined as low volume metastatic disease with limited number and size of metastatic lesions (up to five and not necessarily in the same organ). This definition is proposed in the Advanced Breast Cancer guidelines that are developed as a joint effort from European School of Oncology and European Society of Medical Oncology. Several retrospective studies demonstrated survival benefit of locoregional therapy in addition to systemic therapy. Locoregional therapy consisted of surgical resection, radiation therapy, ablation therapy, etc. However, it remains unclear about survival benefit of combined therapy in oligometastatic BC. To improve the standard of cancer treatment through the cooperate studies on more effective therapeutic strategies based on drugs, surgery and/or radiotherapy, Federation of Asian Clinical Oncology (FACO) was established in 2012 by Chinese Society of Clinical Oncology (CSCO), Korean Society of Medical Oncology (KSMO) and Japan Society of Clinical Oncology (JSCO). Thus, FACO conducted a retrospective cohort study on oligometastatic BC. The primary endpoint is to compare the estimated 5-year overall survival (OS) of oligometastatic BC patients treated with combined therapy and systemic therapy alone. To hypothesize that combined therapy has more advantage of OS in oligometastatic BC, the 5-year OS rates are expected to be 50% and 40%, respectively. The estimated sample size is calculated to be the number of 698 cases (349 cases in each group) needed to prove the superiority of survival with a two-sided type I error rate of 5% and a statistical power of 80%. Case registry opened in February 2018 and will close in January 2019. We planned to register 700 cases, i.e., 234 cases each from investigators of CSCO, KSMO and JSCO. Update information will be discussed.

Citation Format: Imoto S, Futamura M, Toi M, Fujiwara Y, Ueno T, Im Y-H, Im S-A, Ahn SG, Lee JE, Park YH, Wang K, Kitagawa Y, Nishiyama M. International retrospective cohort study of locoregional and systemic therapy in oligometastatic breast cancer (OLIGO-BC1) [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 OT2-05-02.

Abstract P3-03-02: Redo sentinel lymph node biopsy for ipsilateral breast tumor recurrence after breast conserving surgery with negative sentinel nodes: A pooled analysis from a systematic review and two institutes

Background:Cases of redo sentinel lymph node biopsy (SLNB) are growing according to the increase of ipsilateral breast tumor recurrence (IBTR) after breast-conservative surgery (BCS). To evaluate a feasibility of redo SLNB in patients with IBTR after negative SLN, we conveyed a pooled analysis using data from a systematic review and two institutes.

Materials and methods:A systematic search of PubMed was conducted to identify data of patient level from publications evaluating redo SLNB for cases with IBTR. Eligible patients who underwent BCS and were confirmed as negative axilla after SLNB were identified. An identification rate (IR) and a false-negative rate (FNR) were calculated. To identify FNR, we only included cases with back-up axillary node dissection (ALND) from retrieved data.

Results:In a systematic review, a total of 197 peer-reviewed publications were retrieved, of which 19 papers included patients who met eligibility criteria. Data from 464 patients were collected. In two-institutes, 38 cases with same criteria were identified. A total of 502 patient's data were pooled. The IR of redo-SLNB was 71.7% (360/502) in pooled data. For the FNR, data from 147 patients with back-up ALND after SLNB was analyzed. The FNR and accuracy of redo-SLNB were 9.8% (5/51) and 97% (142/147).

Conclusions:We found that the IR and the FNR of redo SLNB were 71.7% and 9.8%, respectively. Redo SLNB is reliable procedure for axillary staging in patients with IBTR after negative SLNB.

Citation Format: Yoon C-i, Bae SJ, Choi JE, Cha CH, Park SE, Ahn SG, Jeong J. Redo sentinel lymph node biopsy for ipsilateral breast tumor recurrence after breast conserving surgery with negative sentinel nodes: A pooled analysis from a systematic review and two institutes [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 P3-03-02.

Abstract P4-02-11: Accuracy of breast magnetic resonance imaging has limited value to reduce the margin-positive rate: A study in relation to the molecular subtypes

Background: Newly released guideline standardizing a negative margin after breast-conservative surgery (BCS) as “no ink on tumor” by SSO-ASTRO stressed the importance of estimation tumor extent with comprehensive breast imaging studies. To evaluate clinical value of breast magnetic resonance imaging (MRI) in patients with BCS, we compared the degree of correlation between MRI-pathology and ultrasonography (US)-pathology according to subtypes. In addition, we investigated the margin-positive rates and secondary operation rates for margin clearance.

Methods: We identified patients with invasive breast cancer who had preoperative breast MRI and ultrasound between 2011 and 2016. We excluded patients having large tumor more than 5cm or multiple tumors or undergoing mastectomy. Patients were classified into 4 subtypes based on the immunohistochemistry; luminal A, luminal B/HER2, HER2, triple-negative breast cancer (TNBC). Lin's concordance correlation coefficient was used to measure the agreement between the MRI or US and tumor extent. Tumor extent was defined as pathologic tumor size including in situ carcinoma. Margin-positivity was assessed based on intraoperative frozen examination.

Results: A total 516 patients with single tumor undergoing BCS were included. Means of tumor size were 1.99 ± 0.91 cm by pathologic examination, 1.91 ± 1.01 cm by MRI, and 1.76 ± 0.92 cm by US, respectively. The correlation coefficient of MRI-pathology was significantly higher than that of US-pathology (r=0.6975 vs. 0.6211, P=0.001). A superiority of MRI than US in measuring pathologic extent was only observed in TNBC (r=0.8089 vs. 0.6014, P<0.001), whereas the agreement between the MRI or US and tumor extents was low in the HER2 (MRI: 0.3509, US: 0.3165). Also, the margin-positive rate was higher in HER2 (luminal A, 11.6%; luminal B/HER2, 17.5%; HER2, 29.6%; TNBC, 17.8%; P=0.0382). In the post-hoc test, the HER2 was more likely to have positive margin compared to Luminal A (P=0.0039). There is no significant difference in secondary operation as margin clearance according to the subtypes (P>0.999).

Margin positive and re-excision rates according to the subtypes Luminal A (n=302)Luminal B (n=80)HER2 (n=27)TNBC (n=107)P valuePositive margin35 (11.6)14 (17.5)8 (29.6)19 (17.8)0.0382Re-excision14 (4.6)4 (5.0)1 (3.7)5 (4.7)>0.9999

Conclusions: Given a superiority of MRI to US in preoperative assessment, MRI-guided BCS did not reduce the margin-positive rate in TNBC. In the HER2, size correlation of MRI-pathology was very low, and the margin-positive rate was high. Collectively, our findings suggest that accuracy of MRI has limited value to reduce the margin-positive rate.

Citation Format: Bae SJ, Ahn SG, Yoon C, Cha YJ, Jeong J. Accuracy of breast magnetic resonance imaging has limited value to reduce the margin-positive rate: A study in relation to the molecular subtypes [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-11.

Abstract P2-01-36: Ex vivo shear-wave elastography of axillary lymph nodes predicting nodal metastasis in patients with primary breast cancer: A pilot study

Objective: To evaluate the feasibility of shear-wave elastography using breast ultrasonography in identifying metastasis of removed sentinel lymph nodes during the operation for treatment of breast cancer.

Background: Conventional method for identification of sentinel nodal metastasis is time and cost consuming. The optimal method for identification of nodal status is important.

Methods: Excised sentinel lymph nodes during the operation were prospectively examined with the elastography. Metastatic status of lymph nodes was confirmed with permanent histology. Only macrometastasis was regarded as positive. Elastic values measured by the ex vivo elastography and nodal characteristics were analyzed to correlate with nodal metastasis.

Results: A total of 274 lymph nodes harvested from 68 breast cancer patients at Gangnam Severance Hospital from May 2014 to April 2015 were included this study. There was the difference of elastic values between nodes with and without metastasis (mean stiffness, 41.6 kPa and 17.4 kPa, P < 0.001). Mean sizes of metastatic nodes (range 0.36-2.59 cm) were significantly larger than that of non-metastatic nodes (1.0 cm versus 0.75 cm, P < 0.001). Moreover, there was a correlation between the size of metastatic nodes which ranged from 0.7 to 21.5 mm with a median of 7 mm and nodal stiffness (correlation coefficient of mean stiffness, r = 0.431). The area under the receiver operating characteristic curve (AUC) by the mean stiffness was 0.794. The combination of size of nodes, mean stiffness and ratio made AUC of 0.856.

Conclusions: In our study, ex vivo shear-wave elastography of sentinel lymph nodes was a feasible method to predict metastasis. Through the validation study, ex vivo elastography could be helpful to determine metastasis of sentinel lymph nodes during the operation.

Keywords Breast cancer; Elastography; Lymph node metastasis.

Citation Format: Lim JW, Lee HW, Park JT, Ahn SG, Jung J. Ex vivo shear-wave elastography of axillary lymph nodes predicting nodal metastasis in patients with primary breast cancer: A pilot study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-36.

Abstract P3-07-10: The association between the expression of progesterone receptor and clinical benefit of adjuvant trastuzumab in estrogen receptor-positive and HER2-positive breast cancer patients

Background: Previous studies have shown that progesterone receptor (PR) status has a prognostic value in hormone receptor-positive breast cancer. In this study, we evaluated the clinical significance of PR status in estrogen receptor (ER)-positive and HER2-positive breast cancer.

Methods: We retrospectively analyzed the data of ER+ and HER2+ breast cancer patients who underwent surgery at Gangnam Severance hospital and Severance hospital from 2002 to 2012. We excluded patients who had a history of previous cancer, received neoadjuvant chemotherapy, did not received adjuvant chemotherapy, and had contralateral breast cancer or metastasis at diagnosis. A total of 346 patients were identified. Among them, 155 patients (44.8%) received adjuvant trastuzumab.

Results: At a median follow-up of 59 months, median disease-free survival (DFS) and overall survival (OS) were 56 and 59 months, respectively. The DFS and OS showed no difference according to PR status in overall patients. Then, these patients were categorized into two groups: ER+/HER2+/PR+ and ER+/HER2+/PR-. In ER+/HER2+PR+ patient, there was no difference of DFS or OS according to trastuzumab use. In ER+/HER2+/PR- patients, DFS was significantly better in patients who received adjuvant trastuzumab treatment compared to those who did not (p=0.009). We also analyzed influence of PR status on treatment outcome between patients who received adjuvant trastuzumab and those who did not. In patients who received adjuvant trastuzumab, there was no difference of DFS or OS according to PR status. However, in patients who did not receive adjuvant trastuzumab, ER+/HER2+/PR- patients showed worse DFS than ER+/HER2+/PR+ patients (p=0.006).

Conclusions: In patients with ER+/HER2+ breast cancer, we found that a prognostic value of PR only retained in those who did not receive adjuvant trastuzumab. Our findings suggest that the use of adjuvant trastuzumab may offer less clinical benefit for the patients with ER+/HER2+/PR+ breast cancer.

Citation Format: Lee HW, Ahn SG, Park JT, Yang BS, Park S, Jeong J, Kim SI. The association between the expression of progesterone receptor and clinical benefit of adjuvant trastuzumab in estrogen receptor-positive and HER2-positive breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-10.

Abstract P6-05-21: High standardized uptake value of 18F-fluorodeoxy-glucose positron emission tomography is related with FOXM1 expression, which negatively influences survival in breast cancer patients

Background

Standardized uptake value (SUV), which is an indicator reflecting glucose uptake in 18F-fluorodeoxy-glucose positron emission tomography (18FDG-PET), can be implicated to be a prognostic factor in various malignant tumors. Using a data set with gene expression profiling, we tried to uncover a molecular marker associated with a high SUV, along with an exploration its prognostic value in breast cancer.

Methods

Microarray gene expression profiling was performed in 287 breast tumor samples. Five hundred nanograms of total RNA were used for labeling and hybridization, according to the manufacturer's protocols (Illumina, San Diego, CA). In 66 samples with SUV, genes with expression patterns highly correlated with the value of SUV were selected for cluster analysis. Five hundred thirty tree gene features were selected for analysis. Patients were divided into the following two groups: SUV-high cluster and SUV-low cluster. Hierarchical clustering analysis based on 533 gene features. The prognostic value of the identified gene was validated in 287 samples and the online public set.

Results

Gene network analysis using Ingenuity Pathway Analysis software revealed considerable enrichment of the gene network toward FOXM1 in the SUV-high cluster, suggesting that its activation might be a key determinant associated with SUV level. Also, the expression of many marker genes for cell proliferation, such as AURKA, AURKB, BIRC5, BUB1, and TOP2A, was significantly higher in the SUV-high cluster than in the SUV-low cluster. Next, in the 287 patients with known FOXM1 expression levels, the Kaplan-Meier survival analysis revealed a negative prognostic impact of highly expressed FOXM1 for overall survival (OS), disease-free survival (DFS), and distant-metastasis-free survival (DMFS) (P = 0.002, P = 0.015, P = 0.008, respectively; Table 1). To validate a prognostic impact of FOXM1 in an external data, we performed a survival analysis using online gene-expression array data. There was significant correlation between the FOXM1 expression level and OS, DFS and DMFS.

Conclusion

Here we analyzed FOXM1 as a biomarker associated with a high SUV and demonstrated that FOXM1 is a negative prognostic factor in breast cancer.

Prognostic significance of FOXM1 in 287 patients Overall SurvivalBreast cancer-specific survivalDisease-free survivalDistant metastasis-free survivalFOXM1 high (n = 144)log-rank testlog-rank testlog-rank testlog-rank testFOXM1 low (n = 133)P = 0.002P = 0.001P = 0.015P = 0.008

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-05-21.

Proyl isomerase Pin1 facilitates ubiquitin-mediated degradation of cyclin-dependent kinase 10 to induce tamoxifen resistance in breast cancer cells

Endocrine therapies that inhibit estrogen receptor (ER)-α signaling are the most common and effective treatment for ER-α-positive breast cancer. However, the use of these agents is limited by the frequent development of resistance. The aim of this study was to elucidate the mechanisms by which downregulation of CDK10 expression confers resistance to tamoxifen in breast cancer. Here, we show that peptidyl-prolyl isomerase Pin1 downregulates CDK10 protein as a result of its interaction with and ubiquitination of CDK10, thereby affecting CDK10-dependent Raf-1 phosphorylation (S338). Pin1(-/-) mouse embryonic fibroblasts (MEFs) show higher CDK10 expression than Pin1(+/+) MEFs, whereas CDK10 protein was downregulated in the rescued Pin1(-/-) MEFs after reexpression of Pin1. Pin1 silencing in SKBR-3 and MCF7 cells increased the CDK10 expression. In human tamoxifen-resistant breast cancer and tamoxifen-resistant MCF7 cells, immunohistochemical staining and immunoblotting analysis shows an inverse correlation between the expression of CDK10 and the degree of tamoxifen resistance. There was also a positive correlation between the high level of P-Raf-1 (Ser338) and Pin1 in human tamoxifen-resistant breast cancer and tamoxifen-resistant MCF7 (TAMR-MCF7) cells. Importantly, 4-OH tamoxifen (4-OHT), when used in combination with overexpressed CDK10 or Raf-1 inhibitor, increased cleaved PARP and DNA fragmentation to inhibit cologenic growth of MCF7 cells and Tamoxifen-resistant MCF7 cells, respectively. On the basis of these findings, we suggest that the Pin1-mediated CDK10 ubiquitination is a major regulator of tamoxifen-resistant breast cancer cell growth and survival.

Effect of reinforcement particle size on the tribological properties of nano-diamond filled polytetrafluoroethylene based coating

The tribological properties of PTFE composite coatings reinforced by nano-diamonds were investigated. Mechanical particle size reduction and dispersion of nano-diamond aggregates were performed by milling with ceramic beads in an organic solvent. Particle size was controlled by the milling time. Pastes comprising a PTFE solution mixed with nano-diamond having various sizes were coated on the aluminum substrate. Ball-on-plate type wear test was performed to investigate the friction and wear behavior. The results indicated that the addition of nano-diamonds effectively improved tribological performance of the PTFE coating. The reduction in nano-diamond sizes were not always improved the wear resistance of PTFE coating. This unexpected behavior was explained by observation on the worn surfaces and wear debris.

Calcifications in a clear cell mucoepidermoid carcinoma of the hard palate

Although calcification is a common finding in inflammatory salivary gland disorders, salivary gland tumour rarely shows calcifications. A case of clear cell mucoepidermoid carcinoma (MEC) of the hard palate with extensive intratumoural calcifications visible on computed tomography (CT) scans and histologic sections is described. The calcification in the salivary gland tumour of the palate recognized by a CT scan should be considered in the differential diagnosis of a MEC. The mechanism of the intratumoural calcification in our case is speculated to be a result of a secretory function of the tumour cells.

The loop domain of heat shock transcription factor 1 dictates DNA-binding specificity and responses to heat stress

Eukaryotic heat shock transcription factors (HSF) regulate an evolutionarily conserved stress-response pathway essential for survival against a variety of environmental and developmental stresses. Although the highly similar HSF family members have distinct roles in responding to stress and activating target gene expression, the mechanisms that govern these roles are unknown. Here we identify a loop within the HSF1 DNA-binding domain that dictates HSF isoform specific DNA binding in vitro and preferential target gene activation by HSF family members in both a yeast transcription assay and in mammalian cells. These characteristics of the HSF1 loop region are transposable to HSF2 and sufficient to confer DNA-binding specificity, heat shock inducible HSP gene expression and protection from heat-induced apoptosis in vivo. In addition, the loop suppresses formation of the HSF1 trimer under basal conditions and is required for heat-inducible trimerization in a purified system in vitro, suggesting that this domain is a critical part of the HSF1 heat-stress-sensing mechanism. We propose that this domain defines a signature for HSF1 that constitutes an important determinant for how cells utilize a family of transcription factors to respond to distinct stresses.

3-deazaadenosine, a S-adenosylhomocysteine hydrolase inhibitor, has dual effects on NF-kappaB regulation. Inhibition of NF-kappaB transcriptional activity and promotion of IkappaBalpha degradation

Previously we reported that 3-deazaadenosine (DZA), a potent inhibitor and substrate for S-adenosylhomocysteine hydrolase inhibits bacterial lipopolysaccharide-induced transcription of tumor necrosis factor-alpha and interleukin-1beta in mouse macrophage RAW 264.7 cells. In this study, we demonstrate the effects of DZA on nuclear factor-kappaB (NF-kappaB) regulation. DZA inhibits the transcriptional activity of NF-kappaB through the hindrance of p65 (Rel-A) phosphorylation without reduction of its nuclear translocation and DNA binding activity. The inhibitory effect of DZA on NF-kappaB transcriptional activity is potentiated by the addition of homocysteine. Taken together, DZA promotes the proteolytic degradation of IkappaBalpha, but not IkappaBbeta, resulting in an increase of DNA binding activity of NF-kappaB in the nucleus in the absence of its transcriptional activity in RAW 264.7 cells. The reduction of IkappaBalpha by DZA is neither involved in IkappaB kinase complex activation nor modulated by the addition of homocysteine. This study strongly suggests that DZA may be a potent drug for the treatment of diseases in which NF-kappaB plays a central pathogenic role, as well as a useful tool for studying the regulation and physiological functions of NF-kappaB.

Identification of cDNAs for Sox-4, an HMG-Box protein, and a novel human homolog of yeast splicing factor SSF-1 differentially regulated during apoptosis induced by prostaglandin A2/delta12-PGJ2 in Hep3B cells

We have examined specific genes whose expression is altered during apoptosis induced by prostaglandin (PG)A2 and Delta12-PGJ2 in human hepatocellular carcinoma Hep3B cells. Using mRNA differential display, we have identified two genes: one is specifically up-regulated and encodes for human Sox-4 (Sry-HMG box gene) and the other is significantly down-regulated and is the human homolog of yeast Ssf-1, a novel splicing factor. Northern blot analysis confirmed their differential expressions. Interestingly, Sox-4 was highly expressed in subcutaneous tumors grown in nude mice as a xenograft from Hep3B cells. These results suggest that the expression of Sox-4 may be related to the apoptosis pathway leading to cell death as well as to tumorigenesis, and that Ssf-1 gene may serve as a negative regulator of PGA2/Delta12-PGJ2-mediated Hep3B cell apoptosis.

The role of c-Myc and heat shock protein 70 in human hepatocarcinoma Hep3B cells during apoptosis induced by prostaglandin A2/Delta12-prostaglandin J2

Prostaglandin (PG) A2 (PGA2) and Delta12-PGJ2 have potent antiproliferative activity on various tumor cell growths in vitro. In this study, we investigated the mechanism of PGA2/Delta12-PGJ2-mediated apoptosis, including intracellular apoptosis-related genes in human hepatocarcinoma Hep3B cells. Hep3B cells treated with PGA2/Delta12-PGJ2 showed that a time-dependent DNA fragmentation characterized by marked apoptosis and the elevation of c-myc mRNA expression. In proportion to the increased c-myc gene transcription, heat shock protein 70 (hsp70) mRNA was induced from 1 to 24 h after PGA2/Delta12-PGJ2 treatment. The transfection of c-myc antisense oligomers in Hep3B cells significantly delayed the induction of HSP70 expression and blocked formation of DNA fragmentation by PGA2/Delta12-PGJ2. Moreover, overexpressed HSP70 showed an increased resistance to apoptosis by PGA2/Delta12-PGJ2 treatment. These results demonstrated that the decreased survival in response to PGA2/Delta12-PGJ2 was causally related to the amount of c-myc and the induction of c-myc regulated the elevation of HSP70 which have been known to correlate with a resistance to apoptosis.