PARP-1 expression and activity in primary human lung cells

Light dose effect of photodynamic therapy on growth inhibition and apoptosis induction in non-small cell lung cancer: A study in nude mouse model

BACKGROUND

Photodynamic therapy (PDT) is receiving increasing attention in treating non-small cell lung cancer (NSCLC) worldwide, but in clinical practice, the relationship between treatment effect and PDT light dose in NSCLC remains unclear. Therefore, we aimed to determine the optimal light dose for PDT by exploring molecular biomarkers and evaluating tumor growth data.

METHODS

We applied bioinformatics to identify promising genes and pathways in NSCLC and PDT. Then, the human lung adenocarcinoma cell line A549-bearing BALB/c nude mice were treated with hematoporphyrin derivative (HPD, 3 mg/kg) that is currently used widely for lung cancer treatment in the world even with photosensitization issues. After 48 h, tumor-bearing mice were irradiated superficially at doses of 100, 200, 300, 400, and 500 J/cm2. The tumor growth data and apoptotic molecules were assessed and calculated.

RESULTS

Bioinformatics results indicated that the apoptosis pathway was significantly enriched and caspase 3 was the most promising biomarker on prognosis in NSCLC-PDT. Compared to the untreated group, there was no difference in the relative tumor volume (RTV) of the 100 J/cm2 group, while the RTV of the other treatment groups (200-500 J/cm2) was significantly lower. In the 100 J/cm2 group, there were significant differences in the complete remission (CR, 0 %) and the percentage of tumor growth inhibition rate (TGI%) over 75 % (20 %) compared with the other treatment groups, especially the 300 and 400 J/cm2 groups (CR 70 %; TGI% 90 %). In the 300 and 400 J/cm2 groups, the expression of caspase 3, cleaved-caspase 3, PARP1, and Bax was increased significantly, while Bcl-2 expression was significantly lower.

CONCLUSIONS

Moderate doses of PDT (300 or 400 J/cm2) are more effective than low (100 or 200 J/cm2) or high doses (500 J/cm2) in the A549 tumor-bearing mice model. Since the A549 tumor is more akin to human tumors in pathological behavior, these experimental data may contribute to improving HPD-PDT illumination protocols for favorable clinical outcomes.

Sensitive detection of PARP-1 activity by electrochemical impedance spectroscopy based on biomineralization

Poly(ADP)ribose polymerase-1 (PARP-1) has attracted much attention as a tumor marker in recent years. Based on the large negative charge and hyperbranched structure of PARP-1 amplified products (PAR), many detection methods have been established. Herein, we proposed a label-free electrochemical impedance detection method based on the large amount of phosphate groups (PO₄^3-) on the surface of PAR. Although EIS method has high sensitivity, it is not sensitive enough to discern PAR effectively. Therefore, biomineralization was incorporated to increase the resistance value (R_ct) distinctly because of the poor electrical conductivity of CaP. During biomineralization process, plentiful Ca²⁺ was captured by PO₄^3- of PAR through electrostatic interaction, resulting in an increasing R_ct of modified ITO electrode. In contrast, when PRAP-1 was absent, only a little Ca²⁺ was adsorbed on the phosphate backbone of the activating dsDNA. As a result, the biomineralization effect was slight and only a negligible R_ct change occurred. Experiment results showed that R_ct was associated closely with the activity of PARP-1. There was a linear correlation between them when the activity value was in the range of 0.005-1.0 U. The calculated detection limit was 0.003 U. Results of real samples detection and the recovery experiments were satisfactory, indicating the method has an excellent application prospect.

Poly (ADP-Ribose) Polymerase 1 Protein Expression in Normal Pancreas and Pancreatic Adenocarcinoma

Pancreatic cancer is a most frequent cancer in Europe, and the majority of cases of cancer of the pancreas are diagnosed above the age of 65. Radical surgery is the first curative treatment of pancreatic cancer, and alternative or combined therapeutic options, in particular, consist of adjuvant or neoadjuvant chemotherapy, with or without radiotherapy. Many factors, including diet and genetics, have been implicated in the development of cancer of the pancreas. Poly (ADP-ribose) polymerase 1 (PARP-1) protein is required for translocation of the apoptosis-inducing factor (AIF) from the mitochondria to the nucleus. It is involved in programmed cell death processes. Different PARP-1 gene expression proteins have been observed in various tumors such as lung, ovarian, endometrial, skin, and glioblastoma. We evaluated the expression of PARP-1 protein in pancreatic adenocarcinoma and normal pancreas tissues by immunohistochemistry. Protein PARP-1 in the nucleus was found in all samples (normal pancreas and pancreatic adenocarcinoma tissues). No cytoplasmic staining was observed in any sample. PARP-1-positive cells resulted higher in the normal pancreas compared with the pancreas with adenocarcinoma. PARP-1 overexpression in prostate cancer tissue compared with normal prostate suggests a greater activity of PARP-1 in these tumors. These findings suggest that PARP-1 expression in prostate cancer is an attempt to trigger apoptosis in this type of tumor, similarl to that reported in other cancers. This finding suggests that PARP-1-mediated cell death pathways are inhibited in this cancer.

High specificity and efficiency electrochemical detection of poly(ADP-ribose) polymerase-1 activity based on versatile peptide-templated copper nanoparticles and detection array

Poly(ADP-ribose) polymerase-1 (PARP-1) activity is closely related to tumor, which is a promising biomarker for cancer diagnosis. So far, only a few methods have been developed for PARP-1 activity assay because both PARP-1 and its catalytic products lack valuable optical or electrochemical property. Herein, we propose a more specific method to label probes on great deal of phosphate groups of PAR. Firstly, versatile peptides were used to prepare CuNPs. This peptide not only worked as reducing agent to prepare CuNPs but also had guanidine groups to label PAR autonomously and specifically. Unlike most previously reported methods based on unspecific electrostatic interactions, CuNPs probes covered by guanidine groups labelled PAR with phosphate groups via intense covalent-like interactions. On the other hand, PARP-1 catalyzed the formation of PAR in each isolated reaction container of the detection array, realizing the high-throughput detection and enhancing the detection efficiency. Ultimately, CuNPs were oxidized into Cu²⁺ and precisely detected by stripping voltammetry. Hence, selectivity and efficiency of PARP-1 detection were both improved. Meanwhile, this approach was successfully used to detect the efficiency of PARP-1 inhibitor and the PARP-1 contents in real cells, indicating its great potential for clinical diagnosis and high-throughput PARP-1 inhibitor screen.

A label-free PFP-based photoelectrochemical biosensor for highly sensitive detection of PARP-1 activity

Poly(ADP-ribose) polymerase-1 (PARP-1), as an original tumor marker, has aroused wide attention in recent years. However, only a few researches have been done for PARP-1 activity detection because PARP-1 is lack of optical or electrochemical property. In this work, a label-free and high-sensitive photoelectrochemical (PEC) biosensor for PARP-1 activity detection based on poly[9,9-bis(6'-N,N,N-trimethylammonium)hexyl]fluorenylene phenylene (PFP) has been designed. To the best of our knowledge, it is the first time that PEC has been used to monitor PARP-1 activity. PARP-1 were activated under the function of activated dsDNA, as a result, branched polymers of ADP-ribose (PAR) with plentiful negative charge were formed in the presence of nicotinamide adenine dinucleotide (NAD⁺). Subsequently, positively charged PFP with good photoelectrochemical properties, were absorbed on PAR via electrostatic interaction. High photocurrent was produced under light induction, which was depended on the PARP-1 activity. The biosensor has a wide linear range from 0.01 to 2 U with a detection limit of 0.007 U. The strategy has been applied in breast and ovarian cancer cells to detection PARP-1 activity with approving results, which signifies that it is a promising tool for clinical diagnosis.

Detection of PARP-1 activity based on hyperbranched-poly (ADP-ribose) polymers responsive current in artificial nanochannels

The cellular enzyme poly ADP (ADP: adenosine diphosphate)-ribose polymerase-1 (PARP-1) plays key roles in DNA repair. Its activity is closely related to various cancer developments. Detection of PARP-1 activity is significant, however, it is relatively difficult since it lacks superiority property that can be used to detect conveniently. PARP-1 lead to the synthesis of hyperbranched poly (ADP-ribose) polymers (PAR) using nicotinamide adenine dinucleotide (NAD⁺) as substrate during DNA damage repairing. In this paper, we found that hyper-branched PAR increased the steric hindrance and reduced the flux of probe ions effectively in anodic aluminum oxide (AAO) nanochannels. To the best of our knowledge, few papers have been reported that hyper-branched polymer has the similar effects in nanochannels as G-quadruplex DNA. Thus, a novel and simple strategy for PARP-1 detection has been proposed due to its great impacts on the diffusion flux of ferricyanide in AAO. It is also proved that electrostatic repulsion is another important factor to influence the current. The method is label-free, simple and sensitive. Quantitative detection of PARP-1 activity was achieved with the detection limit of 0.006 U, which is lower or comparable to the most reported methods. The method has good accuracy and reproducibility. The strategy has been used to detect PARP-1 activity in real breast cancer cells and to evaluate PARP-1 inhibitors with satisfactory results, indicating that it is a potential powerful tool for clinical diagnosis and drug development in the future.

Poly (ADP-ribose) polymerase 1 protein expression in normal and neoplastic prostatic tissue

A genetic background has been implicated in the development of prostate cancer. Protein microarrays have enabled the identification of proteins, some of which associated with apoptosis, that may play a role in the development of such a tumor. Inhibition of apoptosis is a co-factor that contributes to the onset and progression of prostate cancer, though the molecular mechanisms are not entirely understood. Poly (ADP-ribose) polymerase 1 (PARP-1) gene is required for translocation of the apoptosis-inducing factor (AIF) from the mitochondria to the nucleus. Hence, it is involved in programmed cell death. Different PARP-1 gene expression has been observed in various tumors such as glioblastoma, lung, ovarian, endometrial, and skin cancers. We evaluated the expression of PARP-1 protein in prostatic cancer and normal prostate tissues by immunohistochemistry in 40 men with prostate cancer and in 37 normal men. Positive nuclear PARP-1 staining was found in all samples (normal prostate and prostate cancer tissues). No cytoplasmic staining was observed in any sample. PARP-1-positive cells resulted significantly higher in patients with prostate carcinoma compared with controls (P<0.001). PARP-1 over-expression in prostate cancer tissue compared with normal prostate suggests a greater activity of PARP-1 in these tumors. These findings suggest that PARP-1 expression in prostate cancer is an attempt to trigger apoptosis in this type of tumor similarly to what reported in other cancers.

PARP-1 protein expression in glioblastoma multiforme

One of the most common type of primary brain tumors in adults is the glioblastoma multiforme (GBM) (World Health Organization grade IV astrocytoma). It is the most common malignant and aggressive form of glioma and it is among the most lethal ones. Poly (ADP-ribose) polymerase 1 (PARP-1) gene, located to 1q42, plays an important role for the efficient maintenance of genome integrity. PARP-1 protein is required for the apoptosis-inducing factor (AIF) translocation from the mitochondria to the nucleus. PARP-1 is proteolytically cleaved at the onset of apoptosis by caspase-3. Microarray analysis of PARP-1 gene expression in more than 8,000 samples revealed that PARP-1 is more highly expressed in several types of cancer compared with the equivalent normal tissues. Overall, the most differences in PARP-1 gene expression have been observed in breast, ovarian, endometrial, lung, and skin cancers, and non-Hodgkin's lymphoma. We evaluated the expression of PARP-1 protein in normal brain tissues and primary GBM by immunohistochemistry. Positive nuclear PARP-1 staining was found in all samples with GBM, but not in normal neurons from controls (n=4) and GBM patients (n=27). No cytoplasmic staining was observed in any sample. In conclusion, PARP-1 gene is expressed in GBM. This finding may be envisioned as an attempt to trigger apoptosis in this tumor, as well as in many other malignancies. The presence of the protein exclusively at the nucleus further support the function played by this gene in genome integrity maintenance and apoptosis. Finally, PARP-1 staining may be used as GBM cell marker.