Expression of poly (adenosine diphosphate-ribose) polymerase and p53 in epithelial ovarian cancer and their role in prognosis and disease outcome

Correlation of Poly (adenosine diphosphate[ADP]-ribose) Polymerase Expression and Prognosis in Ovarian Cancer: A Systematic Review and Meta-analysis

PURPOSE

This meta-analysis evaluated the correlation between poly (adenosine diphosphate [ADP]-ribose) polymerase (PARP) expression and prognosis in patients with ovarian cancer.

METHODS

Eligible studies were extracted from the electronic databases of PubMed, Web of Science, and EMBASE until 1 August 2019. The included studies investigated the correlation between PARP expression and clinical outcomes in patients with ovarian cancer. Clinical outcomes are overall survival (OS) and progression free survival (PFS). The clinical data of patients, such as clinicopathologic characteristics and survival, were analyzed. The language was limited to English, and studies conducted at the cellular level, animal studies, and non-original research were excluded. The odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs) were used for this meta-analysis.

RESULTS

A total of 9 eligible studies involving 1230 patients were included in our meta-analysis. Based on the analysis, higher PARP expression was correlated with worse overall survival [OS] (HR,1.64; 95% CI, 1.08-2.49; P = 0.020) in the univariate analysis, whereas results from multivariate analysis indicated that PARP overexpression wasn't statistically associated with worse OS (HR, 1.36; 95% CI, 0.98-1.90; P = 0.069). Moreover, the pooled results revealed that patients with PARP overexpression were not associated with worse histologic grade (OR,2.22; 95% CI, 0.98-5.02; P = 0.06).

CONCLUSION

PARP overexpression maybe associated with poor prognosis and survival in patients with ovarian cancer. The patients with PARP over expression were not tended to have a worse histologic grade. Findings require further validation.

The Prognostic Relevance of Poly (ADP-Ribose) Polymerase Expression in Ovarian Cancer Tissue of Wild Type and BRCA-Mutation Carrier Patients

(1) Background: The mechanism of platinum resistance in ovarian cancer is not fully clarified, but the properly functioning DNA repair mechanism can counteract the effect of conventional anticancer treatment. The objective of our study was to evaluate the expression of an important DNA repair enzyme, the Poly (ADP-Ribose) Polymerase (PARP) expression in epithelial ovarian cancer (EOC) tissues depending on BRCA status and to assess its relationship with platinum resistance. (2) Methods: Immunostaining to highlight PARP protein expression was performed using a rabbit polyclonal anti-PARP antibody. The intensity and distribution of immunostaining were assessed by light. Somatic BRCA1 or BRCA2 mutation carriers were identified with bidirectional sequencing of DNA from archived tumor tissue, if the test could not be performed due to technical reasons from tumor cells, the sequencing was done from peripheral blood cells to identify germline mutation carriers. The median progression-free survival (PFS) was generated for each semiquantitative group of PARP expression among chemotherapy-naive cases at the time of PARP immunohistochemistry. (3) Results: In the overall population, negative PARP immunohistochemistry predicted significant PFS (20.1 vs. 11.9 months, p = 0.001) and OS (49 vs. 114 months, p = 0.014) benefit. Genotype-stratified subgroup analysis in BRCA-negative cases confirmed the role of PARP positivity indicating an unfavorable prognosis in the entire population (relapsed 73.91% vs. 92%; OR: 4.06; p = 0.04). In the cases of the subgroup carrying the BRCA mutation, the presence of PARP expression was not associated with less favorable relapse rates, but with marginal significance for overall survival predicted a lower chance of survival (OS more than 32 months 72.73% vs. 35%; OR: 0.2; p = 0.05). (4) Conclusion: The BRCA wild type patients with strong expression of PARP enzymes before the first set of chemotherapy have a poor prognosis.

The Prognostic Value of PARP Expression in High-Grade Epithelial Ovarian Cancer

In an attempt to clarify the prognostic relevance of poly (ADP-ribose) polymerase (PARP) expression, we analysed the clinical data of 86 high-grade epithelial ovarian cancer (EOC) cases in which PARP immunohistochemistry results were available. Immunostaining to highlight PARP protein expression was performed using a Leica Bond MAX Immunostainer (Leica Microsystems, Wetzlar, Germany). We applied a rabbit polyclonal anti-PARP antibody (ab6079 330, Abcam, Cambridge, UK) for the specific reaction. The intensity and distribution of immunostaining were assessed by light microscopy (Leica DM2500 microscope, DFC 420 camera, and Leica Application Suite V3 software; Leica) and evaluated with a four-grade (0-3+) system. The median progression-free survival (PFS) was generated for each semiquantitative group of PARP expression among chemotherapy-naive cases at the time of PARP immunohistochemistry. Eighty-six cases were chemotherapy-naive at the time of PARP immunohistochemistry, and 41 cases showed no PARP expression. Forty-five cases showed intermediate or high PARP expression. The median PFS among patients in the PARP-negative group was 16 months (interquartile range; IQR 10.7-35.9 months), and the median PFS of patients in the PARP-positive group was 12 months (IQR 6.1-21.8 months). The difference was significant according to the log-rank test (p = 0.01). The median overall survival (OS) of patients in the PARP-negative group was 65 months (IQR 43.6-110.8 months), and the median OS of patients in the PARP-positive group was 52 months (IQR 36.9-66.7 months). The difference was significant according to the log-rank test (p = 0.028). Multiple comparisons confirmed that PARP expression results in a significant difference in PFS and OS achieved by first-line Taxol-carboplatin chemotherapy. The lack of PARP expression assessed by immunohistochemistry may predict improved PFS in ovarian cancer patients after adjuvant platinum-based chemotherapy.

Obesity, DNA Damage, and Development of Obesity-Related Diseases

Obesity has been recognized to increase the risk of such diseases as cardiovascular diseases, diabetes, and cancer. It indicates that obesity can impact genome stability. Oxidative stress and inflammation, commonly occurring in obesity, can induce DNA damage and inhibit DNA repair mechanisms. Accumulation of DNA damage can lead to an enhanced mutation rate and can alter gene expression resulting in disturbances in cell metabolism. Obesity-associated DNA damage can promote cancer growth by favoring cancer cell proliferation and migration, and resistance to apoptosis. Estimation of the DNA damage and/or disturbances in DNA repair could be potentially useful in the risk assessment and prevention of obesity-associated metabolic disorders as well as cancers. DNA damage in people with obesity appears to be reversible and both weight loss and improvement of dietary habits and diet composition can affect genome stability.

PARP-1 regulates DNA repair factor availability

PARP-1 holds major functions on chromatin, DNA damage repair and transcriptional regulation, both of which are relevant in the context of cancer. Here, unbiased transcriptional profiling revealed the downstream transcriptional profile of PARP-1 enzymatic activity. Further investigation of the PARP-1-regulated transcriptome and secondary strategies for assessing PARP-1 activity in patient tissues revealed that PARP-1 activity was unexpectedly enriched as a function of disease progression and was associated with poor outcome independent of DNA double-strand breaks, suggesting that enhanced PARP-1 activity may promote aggressive phenotypes. Mechanistic investigation revealed that active PARP-1 served to enhance E2F1 transcription factor activity, and specifically promoted E2F1-mediated induction of DNA repair factors involved in homologous recombination (HR). Conversely, PARP-1 inhibition reduced HR factor availability and thus acted to induce or enhance "BRCA-ness". These observations bring new understanding of PARP-1 function in cancer and have significant ramifications on predicting PARP-1 inhibitor function in the clinical setting.

Therapeutic potential of patupilone in epithelial ovarian cancer and future directions

Ovarian cancer is the most lethal gynecologic malignancy worldwide with extremely poor patient prognosis. Elucidation of the detailed mechanisms of action of drugs targeting this cancer type is necessary to optimize treatment efficacy. Epothilones, a new class of microtubule-stabilizing anticancer drugs, show strong cytotoxic properties in vitro and in vivo and are additionally effective in taxane-resistant cells. In this report, we focus on inhibitors of microtubule depolymerization, taxanes, and the novel antimicrotubule agents, epothilones. Current knowledge regarding the effects of epothilone B on ovarian tumor cell metabolism is reviewed, along with recent advances in therapeutic strategies, such as novel agents and biologic drug combinations containing epothilone that target aberrant pathways in ovarian cancer.

A PET imaging agent for evaluating PARP-1 expression in ovarian cancer

BACKGROUND

Poly(ADP-ribose) polymerase (PARP) inhibitors are effective in a broad population of patients with ovarian cancer; however, resistance caused by low enzyme expression of the drug target PARP-1 remains to be clinically evaluated in this context. We hypothesize that PARP-1 expression is variable in ovarian cancer and can be quantified in primary and metastatic disease using a novel PET imaging agent.

METHODS

We used a translational approach to describe the significance of PET imaging of PARP-1 in ovarian cancer. First, we produced PARP1-KO ovarian cancer cell lines using CRISPR/Cas9 gene editing to test the loss of PARP-1 as a resistance mechanism to all clinically used PARP inhibitors. Next, we performed preclinical microPET imaging studies using ovarian cancer patient-derived xenografts in mouse models. Finally, in a phase I PET imaging clinical trial we explored PET imaging as a regional marker of PARP-1 expression in primary and metastatic disease through correlative tissue histology.

RESULTS

We found that deletion of PARP1 causes resistance to all PARP inhibitors in vitro, and microPET imaging provides proof of concept as an approach to quantify PARP-1 in vivo. Clinically, we observed a spectrum of standard uptake values (SUVs) ranging from 2-12 for PARP-1 in tumors. In addition, we found a positive correlation between PET SUVs and fluorescent immunohistochemistry for PARP-1 (r2 = 0.60).

CONCLUSION

This work confirms the translational potential of a PARP-1 PET imaging agent and supports future clinical trials to test PARP-1 expression as a method to stratify patients for PARP inhibitor therapy.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02637934.

FUNDING

Research reported in this publication was supported by the Department of Defense OC160269, a Basser Center team science grant, NIH National Cancer Institute R01CA174904, a Department of Energy training grant DE-SC0012476, Abramson Cancer Center Radiation Oncology pilot grants, the Marsha Rivkin Foundation, Kaleidoscope of Hope Foundation, and Paul Calabresi K12 Career Development Award 5K12CA076931.

Inhibition of Topoisomerase IIα and Induction of Apoptosis in Gastric Cancer Cells by 19-Triisopropyl Andrographolide

Gastric cancer is the most common cancer in Eastern Asia. Increasing chemoresistance and general systemic toxicities have complicated the current chemotherapy leading to an urgent need of more effective agents. The present study reported a potent DNA topoisomerase IIα inhibitory activity of an andrographolide analogue (19-triisopropyl andrographolide, analogue-6) in gastric cancer cells; MKN-45, and AGS cells. The analogue was potently cytotoxic to both gastric cancer cell lines with the half maximal inhibitory concentration (IC50 values) of 6.3±0.7 μM, and 1.7±0.05 μM at 48 h for MKN-45, and AGS cells, respectively. It was more potent than the parent andrographolide and the clinically used, etoposide with the IC50 values of >50 μM in MKN-45 and 11.3±2.9 μM in AGS cells for andrographolide and 28.5±4.4 μM in MKN-45 and 4.08±0.5 μM in AGS cells for etoposide. Analogue-6 at 2 μM significantly inhibited DNA topoisomerase IIα enzyme in AGS cells, induced DNA damage, activated cleaved PARP-1, and Caspase3 leading to late cellular apoptosis. Interestingly, the expression of tumor suppressor p53 was not activated. These results show the importance of 19-triisopropyl-andrographolide in its emerging selectivity to primary target on topoisomerase IIα enzyme, inducing DNA damage and apoptosis by p53- independent mechanism. Thereby, the results provide insights of the potential of 19-triisopropyl andrographolide as an anticancer agent for gastric cancer. The chemical transformation of andrographolide is a promising strategy in drug discovery of a novel class of anticancer drugs from bioactive natural products.

Assessment of PARP protein expression in epithelial ovarian cancer by ELISA pharmacodynamic assay and immunohistochemistry

Targeting Poly (ADP-ribose) polymerase 1 (PARP-1) involved in base excision repair (BER) has been shown to be a clinically effective treatment strategy in epithelial ovarian cancer (EOC) defective in homologous recombination (HR). The aim of this study was to evaluate fresh EOC tumor tissue in regard to PAR (Poly (ADP-ribose)) concentration as a surrogate marker for PARP activity and PARP protein expression in archival samples by immunohistochemistry (IHC). The prospective study cohort consisted of 57 fresh tumor samples derived from patients undergoing primary (n = 38) or interval debulking surgery (n = 19) for EOC and parallel archival paraffin-embedded tumor samples. PARP activity in fresh frozen tumor tissue was assessed by an enzymatic chemiluminescence assay and PARP protein expression in paraffin-embedded tumor tissue by IHC. No correlation was detected between PARP enzyme activity and PARP staining by IHC (p = 0.82). High PARP activity was associated with platinum sensitivity both in the entire study cohort (p = 0.022) and in the high-grade subgroup (p = 0.017). High PARP activity was also associated with improved progression-free survival (PFS) (32 vs 14 months, log-rank p = 0.009). However, PARP immunostaining pattern was not predictive of patient survival. In conclusion, we present a novel finding of high PARP activity associated with platinum sensitivity and improved PFS in EOC. There was no association between PARP IHC and pharmacodynamic assay, and the correlation of PARP IHC with clinico-pathological characteristics and patient survival was poor. Pharmacodynamic assay rather than IHC seems to reflect better biologically significant PARP.

Expression of DNA repair proteins in endometrial cancer predicts disease outcome

OBJECTIVE

The consequences of defective homologous recombination and other DNA repair pathways are important in disease outcomes of numerous tumor types. The objective of this study was to explore BRCA1, PARP, FANCD2, PTEN, H2AX, and ATM protein expression in endometrial cancer (EC).

METHODS

PARP1, γH2AX, ATM, FANCD2, PTEN, BRCA1, and p53 proteins were evaluated in EC tissue microarray (TMA) and their expressions were correlated with clinical and pathological parameters in 357 patients.

RESULTS

In type I EC, PARP1(+), ATM(+), and FANCD2(+) were associated with high tumor grade (p 0.031, p 0.0045, p 0.0062 respectively); γH2AX(+) and FANCD2(+) with advanced tumor stage (p 0.0004, p 0.0085 respectively); γH2AX(+), FANCD2(+) and p53(+) with the presence of lympho-vascular invasion (p 0.0004, p 0.0042, p 0.0098 respectively); and γH2AX(+) and ATM(+) with tumor recurrence (p 0.0203, p 0.0465) respectively. In type II EC, only PARP1(+) was associated with tumor stage (p 0.0499). EC patients with p53(+) or FANCD2(+) were more likely to recur with 5year recurrence free survival (RFS) probability of 71.4% in comparison to 85.5% for the other patients and they were more likely to have shorter 5year overall survival (OS) of 66.46% in comparison to 78.5% of those other patients Finally, patients with ATM(+) and p53(+) or FANCD2(+) were more likely to recur with 5year RFS probability of 68% versus 80.3% for the other patients.

CONCLUSION

DNA repair proteins seemed to play an important role in EC, and their expressions can forecast for poor outcomes.

Annexin A11 in disease

Ubiquitously expressed in many cell types, annexin A11 (Anxa11) is a member of the multigene family of Ca(2+)-regulated phospholipid-dependent and membrane-binding annexin proteins. Studies have shown that Anxa11 plays an important role in cell division, Ca(2+) signaling, vesicle trafficking and apoptosis. The deregulation and mutation of Anxa11 are involved in systemic autoimmune diseases, sarcoidosis and the development, chemoresistance and recurrence of cancers. Malfunction of Anxa11 may lead to or enhance the metastasis, invasion and drug resistance of cancers through the platelet-derived growth factor receptor (PDGFR) pathway and/or the mitogen-activated protein kinase (MAPK)/p53 pathway. In a variety of diseases, Anxa11 is most commonly reported to function through interactions with apoptosis-linked gene-2 protein (ALG-2) and/or calcyclin (S100A6). Although it has been little studied, Anxa11 is a promising biomarker for the diagnosis, treatment and prognosis of certain diseases. In this review, the associations of Anxa11 with Ca(2+)-regulated exocytosis, cytokinesis, sex differentiation, autoimmune diseases, thrombolysis and cancers are summarized and interpreted.

Distinct molecular profiles in Lynch syndrome-associated and sporadic ovarian carcinomas

Ovarian carcinoma in Lynch syndrome (LS) is associated with unexpectedly high survival; yet, beyond DNA mismatch repair (MMR) defects, the developmental mechanisms are unknown. We used established (genetic) and new (epigenetic) classifiers of ovarian cancer to explore similarities and differences between LS-associated and sporadic diseases. To this end, all available ovarian carcinomas (n = 20) from MMR gene mutation carriers ascertained through a nation-wide registry and 87 sporadic ovarian carcinomas of the main histological types were molecularly profiled. LS-ovarian carcinomas were mostly of nonserous histology (12 endometrioid, seven clear cell and one serous), diagnosed at a mean age of 45.7 years, and associated with a 10-year survival of 87%. Among LS-ovarian carcinomas, 19/20 (95%) were MMR-deficient vs. 11/87 (13%) among sporadic cases (p < 0.0001). In a striking contrast to the sporadic cases, the expression of p53 was normal and KRAS/BRAF mutations absent in all LS-ovarian carcinomas. PIK3CA mutations, suggested to be a favorable prognostic factor, occurred with a frequency of 6/20 (30%), which was comparable to sporadic tumors of endometrioid or clear cell type. Tumor suppressor genes were more frequently methylated and LINE-1 hypomethylation less common in LS-ovarian carcinomas compared to their sporadic counterparts. The patterns of genetic and epigenetic alterations reflected the origin as LS vs. sporadic cases on one hand and the histological type on the other hand. In conclusion, the significant molecular differences observed between LS-associated and sporadic ovarian carcinomas help explain the different behavior of these tumors and emphasize the need for tailored clinical management.

Poly(adenosine diphosphate-ribose) polymerase expression in BRCA-proficient ovarian high-grade serous carcinoma; association with patient survival

SUMMARY

Ovarian cancers with BRCA mutations rely on the alternative DNA repair mechanism of the poly(adenosine diphosphate-ribose) polymerases (PARP)-dependent base excision repair pathway, with a better overall survival and response to chemotherapy, than BRCA1-proficient cases. This can be enhanced further by using PARP inhibitors. Rate of PARP cleavage may have an independent role from BRCA in contributing to response to chemotherapy. We hypothesize that, regardless of BRCA profile, high expression of PARP1 is associated with poor disease outcome and could be used as a biomarker to identify cases that may have a better response to PARP inhibitors. The expressions of BRCA1, PARP1 in its intact and cleaved (C-PARP1) forms were immunohistochemically semiquantified in 174 sporadic high-grade serous carcinoma patients. Association with clinicopathologic variables and survival was analyzed. PARP1 expression was negatively associated with overall survival and progression-free survival in those patients with low BRCA1 profile (P = .04). Analysis of the combined expression of PARP1 and BRCA1 revealed that high expression of PARP1 is associated with poor survival when combined with either high or low BRCA expression. This was reinforced by multivariate analysis showing PARP1 (P = .034) as an independent prognostic factor. A trend toward worse survival was noted with low levels of C-PARP. PARP1 may have an independent role in response to chemotherapy separate from BRCA gene mutation and partly due to reduced PARP cleavage. An approach to exploit PARP expression as a beneficial biomarker to identify patients suitable for PARP inhibitor therapy is suggested.

Association between polymorphisms of XRCC1 and ADPRT genes and ovarian cancer survival with platinum-based chemotherapy in Chinese population

The role of DNA repair gene polymorphisms in cancer development, progression, and response to treatment has received increased attention. We conducted a prospective study to determine whether associations exist between two polymorphisms in XRCC1 and ADPRT and the outcomes of Chinese ovarian cancer patients treated with platinum-based chemotherapy. A total of 335 new cases of ovarian cancer were consecutively collected between May 2005 and May 2007. Follow-up lasted for 4 years, and the outcome measure was survival time. Individuals carrying XRCC1 194Trp/Trp had a longer survival time than did those with the Arg/Arg genotype. Similarly, those carrying XRCC1 399 Gln/Gln genotypes had 0.44-fold the risk of death than those with the Arg/Arg genotype. The combination of XRCC1 194 Trp allele and 399 Gln allele could decrease the death risk of ovarian cancer. In summary, this study is the first to evaluate the associations between polymorphisms in DNA repair gene polymorphism and the risk of ovarian cancer in Chinese population. Our study found a significant association between XRCC1 Arg399Gln and XRCC1 Arg194Trp polymorphism and the clinical outcome of ovarian cancer. Furthermore, studies with larger sample sizes are still needed to confirm these associations in Chinese population.