Function of PARP1 and Mechanism of Action and Drug Resistance of PARP Inhibitors / 中国生物化学与分子生物学报

Poly ADP⁃ribose polymerase 1 (PARP1) is an important modification enzyme in cells. Its most well⁃known function is to recruit multiple DNA damage repair effector proteins through its own PARylation, such as XRCC1, to participate in DNA single and double strand damage repair. In addition, PARP1 can also provide favorable conditions for DNA damage repair and maintain genomic stability by promoting replication fork stall and nucleosome depolymerization. In recent years, in addition to the function of DNA damage repair, PARP1 has also been found to play an important role in cell apoptosis, autophagy and inflammatory pathways, which is closely related to the occurrence and development of neurodegenerative diseases. PARP inhibitor (PARPi) is an antitumor drug that targets PARP1 and works together with a homologous recombination (HR) deficient phenotype to produce a synthetic lethality. The drug can trap PARP1 and inhibit its activity. On the one hand, it directly interferes with the DNA damage repair pathway that PARP1 participates in; and on the other hand, it also inhibits the selection of PARP1⁃mediated DNA damage repair pathway and replication fork stall, making the cell genome instable. However, tumor cells are often found to be insensitive to PARPi in clinical treatment. Drug resistance of tumor cells to PARPi is highly correlated with mutations of their own genes, which respectively act on cell HR repair pathway, PARP1 circulation pathway, replication fork stability and active drug efflux, etc. Identifying specific mutation sites in drug⁃resistant tumor cells will provide help for clinical treatment. The purpose of this review is to give a description about the functions of PARP1, and focus on the mechanism of action of PARPi, the mutated genes related to drug resistance and their drug resistance mechanism, therefore to deepen the understanding of PARP1 mediated DNA damage repair pathway in cells, and provide new ideas for future clinical treatment.

Screening of a Small Molecule Compound Library Identifies Potential Drugs that Synergize with PARP Inhibitors against Ovarian Cancer Cells / 中国生物化学与分子生物学报

PARP inhibitors are a new class of drugs that target cancer cells with defective DNA repair. Early trials have shown that PARP inhibitors have achieved satisfactory results, but the mechanism of resistance after drug treatment has not been fully revealed. Therefore, it is necessary to find more targeted drugs in combination with PARP inhibitors to kill tumor cells. In this paper, several potential drugs that can synergistically kill ovarian cancer cells with PARP inhibitors were identified based on the combined drug screening of 379 small molecule compound libraries and PARP inhibitor Niraparib through cell proliferation experiments, colony-formation survival experiments and immunofluorescence staining experiments. The results showed that there are eight small molecule compounds with good combination effects, including two small molecule inhibitors STF-118804 and Disulfiram that have been reported to have combined effects with PARP inhibitors. We selected GW441756, an inhibitor of tropomyosin receptor kinase A (TrKA), to verify a variety of tumor cells and explore the preliminary mechanism. The combined therapeutic effects of the Niraparib and the TrKA inhibitor increased the sensitivity of tumor cells to PARP inhibitors (P < 0. 05). Mechanistically, the number of γH2AX foci in the combined treatment group was significantly increased (P<0. 05), indicating that the TrKA inhibitor hindered the DNA damage repair ability. Moreover, combination therapy significantly reduced the formation of RAD51 foci (P<0. 05), a marker of homologous recombination repair (HRR), suggesting that TrKA inhibitors may inhibit DNA damage repair by inhibiting HRR efficiency. Overall, these results suggest that TrKA inhibitor can be used as a potential drug to kill ovarian cancer cells in combination with PARP inhibitors.

Detection of lymph node of rabbit thyroid by real-time fluorescence imaging / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To detect the lymph nodes (LN) of rabbit thyroid by fluorescence imaging and to provide experimental evidence for its clinical application.</p><p><b>METHODS</b>Each of 50 lateral thyroid lobes of 25 rabbits was injected with 0.02 ml of indocyanine green (ICG), and 0.02 ml methylene followed. ICG fluorescence was detected using photodynamic eye (PDE). The methylene staining in LN was also observed. The onset time of ICG staining in LN was measured.</p><p><b>RESULTS</b>The detection rate of fluorescence imaging and blue dye imaging were respectively 86.0% (43/50) and 66.0% (33/50), with a significant difference (P = 0.034), and the accuracy were respectively 85.5% (53/62) and 70.7% (41/58). The onset time (x(-) ± s) of ICG staining in LN was (118.3 ± 16.1) s.</p><p><b>CONCLUSIONS</b>Fluorescence imaging showed satisfied detection rate and accuracy. The detection rate of LN by fluorescence imaging was higher than that by blue dye imaging. Fluorescence imaging could be an alternative method for the detection of LN of thyroid in future clinical practice.</p>

Study of radioactivities in parathyroid and near tissues during radioguided parathyroidectomy / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To determine the radioactivities in parathyroid and near tissues during radioguided parathyroidectomy in patients with hyperparathyroidism and the utility of parathyroidectomy in patients with negative (99m)Tc-sestamibi scans.</p><p><b>METHODS</b>Between August 2010 and August 2011, 21 patients underwent radioguided parathyroidectomy for hyperthyroidism. The levels of parathyroid hormone (PTH) and serum calcium before and after surgery were detected respectively. In vivo and ex vivo radioactivities in parathyroid and near tissues were examined. According to the radioactivity in parathyroid, the patients were divided into two groups, positive group and negative group. All data was descriptively analyzed and underwent a t test and an analysis of variance.</p><p><b>RESULTS</b>In all patients both PTH and calcium levels decreased significantly after parathyroidectomy when compared to those before surgery (t' = 17.71 and t = 10.00, respectively, P < 0.001). In vivo and ex vivo radioactivities in enlarged parathyroid glands were higher than those in thyroid and fat tissue (F = 75.25 and 37.81, respectively, P < 0.001). In vivo and ex vivo radioactivities of the enlarged parathyroid with negative sestamibi scans were significantly greater than background radioactivity.</p><p><b>CONCLUSIONS</b>There are significant differences in (99m)Tc-sestamibi radioactivities among enlarged parathyroid glands, thyroid glands and fat tissues. This radioguided technique is helpful to identify abnormal parathyroid gland in patients with hyperparathyroidism during parathyroidectomy.</p>

Detection of sentinel lymph node of rabbit thyroid by fluorescence imaging / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To detect the sentinel lymph nodes (SLN) of rabbit thyroid by fluorescence imaging and to provide experimental evidence for its clinical application.</p><p><b>METHODS</b>Equal concentration and dose (35 nmol/L, 1 ml) of ICG (indocyanine green) or ICG:CSA (calf serum albumin) complex was injected into rabbit thyroid to measure the their fluorescence amount. Twenty rabbits were randomly divided into ICG group and ICG:CSA group, with 10 rabbits each group, rabbit thyroid was separately injected with 0.02 ml of 100 nmol/L ICG and 0.02 ml of methylene, or 0.02 ml of 35 nmol/L ICG:CSA and 0.02 ml of methylene, and then ICG fluorescence and methylene staining in SLN were detected respectively.</p><p><b>RESULTS</b>Fluorescence amount of ICG:CAS was three times that of ICG with the same concentration and dose. SLNs were showed in all rabbits injected with ICG or ICG:CSA, but found only in 16 of 20 rabbits injected with methylene blue. The accuracy of fluorescence imaging and blue dye imaging were respectively 95.8% and 79.2%.</p><p><b>CONCLUSION</b>Fluorescence imaging, using ICG or ICG:CSA as a tracer, could be an alternative method for the detection of SLN of thyroid in future clinical practice.</p>

Relationship between cervical micrometastasis and early recurrence and prognosis in laryngeal carcinoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To analyse the correlation between the micrometastasis and early recurrence and prognosis in laryngeal cancer.</p><p><b>METHODS</b>Total of 126 patients with laryngeal squamous cell carcinoma were included in the study. The micrometastasis was detected with hematoxylin and eosin staining (HE) and immunohistochemical staining for cytokeratin (CK) of the lymph node specimens after selective neck dissection (II-IV). Chi-square test was used to analyse the relationship between the micrometastasis and early recurrence and prognosis, and Kaplan-Meier method was used for survival analysis.</p><p><b>RESULTS</b>HE staining showed positive micrometastasis in 41 cases and negative micrometastasis in 85 cases in which 33 cases were positive staining for CK. With a following-up of mean 6.3 years, recurrence or metastasis occurred in 15 cases with positive micrometastasis detected by HE staining, 14 cases with CK positive staining and 4 cases with CK negative staining. The correlation between micrometastasis and early recurrence was significant (P < 0.01). The total 5-year survival rate was 79.8%, 10-year survival rate was 60.5%. The 10-year survival rate (52.1%) of the patients with CK positive staining indicating micrometastasis was significantly higher than that of CK negative patients (81.2%, P < 0.01).</p><p><b>CONCLUSION</b>Cervical micrometastasis predicts poor prognosis and early recurrence in patients with laryngeal squamous cell carcinoma.</p>

Long-term treatment outcome in patients undergoing cricohyoidoepiglottopexy for glottic carcinoma / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the long-term results of cricohyoidoepiglottopexy(CHEP) in the treatment of glottic carcinoma.</p><p><b>METHODS</b>A retrospective chart review of 92 consecutive patients who underwent CHEP in the selected institut from January 1990 to December 2008. Of the 92 cases, 41 cases of stage I, 39 cases of stage II, 12 cases of stage III. The time for the decannulation and the removal of the nasal feeding and quality of phonation were used for evaluating postoperative functional rehabilitation. The estimated long-term survival rates were calculated by Kaplan-Meier method.</p><p><b>RESULTS</b>Among 92 patients, 26 cases (27 sides) received neck dissection and lymph nodes were pathologically positive in 3 patients (11.1%). All final surgical margins were negative for tumor invasion. Seven patients had postoperative radiotherapy and one had chemoradiation. Thirteen patients (14.1%) were found local recurrence and nine patients (9.8%) had postoperative metastases. Overall 3-, 5- and 10-year survival rates were 90.0%, 84.5% and 67.0% respectively. Cox multivariate analysis showed that the recurrence had significant influences on the overall survival rate.</p><p><b>CONCLUSION</b>CHEP not only is relatively easy to master, but also effective in the treatment of glottic carcinoma.</p>

Experimental study of cervical lymph node in thyroid by using radioactive nano tracer / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>Using radioactive nano tracer with different sizes (average diameter were 50, 80 and 100 nm) and dosages (0.01 and 0.02 ml) in the thyroids of rabbits, to study the drainage of thyroid to cervical lymph nodes (LNs) in rabbits and to provide experimental evidence for the choice of ideal sizes and dosages of radioactive Nano tracer for the sentinel lymph node biopsy (SLNB) in thyroid cancer patients.</p><p><b>METHODS</b>Thirty adult rabbits were randomly divided into six groups (50 nm - 0.01 ml, 50 nm - 0.02 ml, 80 nm - 0.01 ml, 80 nm - 0.02 ml, 100 nm - 0.01 ml, 100 nm - 0.02 ml of (99m)Tc-Sb(2)S(3)) with five rabbits in each group. A total of 60 sides of thyroids were included. The mean number of LNs with radioactivity, the initial, the strangest and the lasting time of radioactivity in LNs in each group were measured.</p><p><b>RESULTS</b>One to three LNs were identified in one side neck of rabbits, totally 86 LNs. Most of LNs with radioactivity existed in level VI, counting for 75.6% (65/86). (99m)Tc-Sb(2)S(3) with 50 nm particles was significantly better than that with 80 nm or 100 nm particles with regarding the initial and the strangest radioactive time of (99m)Tc-Sb(2)S(3) in LNs (P < 0.05). There were no significant difference in the mean number of LNs with radioactivity, the initial, the strangest and the lasting time of radioactivity between the dosages of 0.01 ml and 0.02 ml of (99m)Tc-Sb(2)S(3) with same size of particles (P > 0.05).</p><p><b>CONCLUSION</b>(99m)Tc-Sb(2)S(3) with 50 nm particles, in the dosage of 0.01 ml or 0.02 ml, could be good choice for SLNB of thyroid cancer.</p>

Expression of epithelial Na+ channel in human nasal polyp / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the expression of epithelial sodium channel in nasal polyps and normal nasal mucosa and to characterize the ENaC-mediated Na(+) absorption and the mechanism of the liquid transport in human upper airway epithelia.</p><p><b>METHODS</b>The tissue from 12 patients with nasal polyps (NP) and the normal ethmoid cornu mucosa (ECM) from 5 patients were obtained through endoscopic surgery. The expression of ENaC was detected by Immunofluorescence and the concentration of ENaC alpha, beta, gamma-mRNA were detected by RT real-time PCR.</p><p><b>RESULTS</b>The ENaC in NP group (35.79 +/- 5.47) was higher than that in ECM group (22.17 +/- 5.43, t = 4.687, P < 0.01). The expression of ENaC-alpha, beta, gamma mRNA in NP group (respectively 2.06 +/- 0.42, 1.97 +/- 0.32, 1.96 +/- 0.54) was higher than that in ECM group (respectively 1.01 +/- 0.10, 0.98 +/- 0.08, 0.97 +/- 0.06; t = 5.482, 6.659, 4.036, all P < 0.01). The mRNA expression of three subunits of ENaC was as follows: alpha > beta > gamma in both groups. The mRNA expression of alpha, beta, gamma subunit of ENaC in NP group was higher than that in ECM group(P < 0.01). The expression of three subunits of ENaC was correlated respectively with that of mRNA in NP group.</p><p><b>CONCLUSIONS</b>The up-regulation of ENaC in human NP was associated with the expression of ENaC mRNA, that made hydrops and might be one of the most important cause of the develop of nasal polyp.</p>

Relationship between ultrasonographic velocimetric parameters and microvessel density in patients with papillary thyroid carcinoma and its clinical significance / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To determine the relationship between velocimetric parameters by using color Doppler ultrasonography and microvessel density (MVD) in papillary thyroid carcinoma and its clinical significance for preoperative diagnosis of papillary thyroid carcinoma. Methods Twenty-nine thyroid tumors were examined preoperatively by color Doppler ultrasonography. The velocimetric parameters including peak systolic velocity (V(max)), end-diastolic velocity (V(min)) were evaluated respectively and resistance index (RI) was calculated. Immunohistochemistry was applied by using polyclonal rabbit anti-human Von Willebrand factor in all cases after operation and microvessel density was calculated based on it.</p><p><b>RESULTS</b>Of the twenty-nine patients who underwent surgery, seventeen patients were diagnosed in papillary thyroid carcinoma and twelve patients in thyroid adenoma. In velocimetric analysis, the RI was significantly higher in patients with papillary thyroid carcinoma than those with thyroid adenoma (t = 3.3108, P < 0.01). V(max) and Vmin were no significance in those two tumors respectively (Z = 0.9520, P > 0.05; Z = - 1.6618, P > 0.05). MVD was also significantly increased in patients with papillary thyroid carcinoma (t = 8.1991, P < 0.01). There was a significant positive association between RI and MVD (r = 0.7924, P < 0.01).</p><p><b>CONCLUSIONS</b>Color Doppler ultrasonography could well display the blood flow of thyroid tissue and its nodules. The velocimetric parameter RI was higher in papillary thyroid carcinoma than in adenoma and was along with its MVD. RI may provide valuable information for diagnosis of papillary thyroid carcinoma preoperatively.</p>

Outcomes of intranasal endoscopic holmium laser-assisted dacryocystorhinostomy in treatment of chronic dacryocystitis / 上海第二医科大学学报

Objective To observe the outcomes of intranasal endoscopic holmium laser-assisted dacryocystorhinostomy in the treatment of chronic dacryocystitis. Methods Forty-seven patients(47 eyes) with chronic dacryocystitis underwent intranasal endoscopic holmium laser-assisted dacryocystorhinostomy.The postoperative follow-up included lacrimal irrigation and intranasal endoscopic examination. Results The patients were followed up for 3 to 6 months.The cure rate was 87.2%,the improvement rate was 6.4%,and the total effective rate(cure rate+improvement rate) was 93.6%.Conclusion Intranasal endoscopic holmium laser-assisted dacryocystorhinostomy causes no scar in the face,less nasal tissue damage,shorter operation time and less hemorrhage,and does not affect the lacrimal irrigation system,which allows correction of intranasal causes of failure in traditional dacryocystorhinostomy.

Clinical research on 2228 cases of thyroid gland tumors / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To discuss outcome of thyroid tumor patients treated with surgery.</p><p><b>METHODS</b>Total number of patients was 2228. These patients of thyroid tumors from 1992-2004 (2072 cases of benign thyroid diseases and 156 cases of thyroid carcinoma) were recruited. The clinical and follow-up datum were retrospective analyzed.</p><p><b>RESULTS</b>(1) Benign thyroid tumors with near-total thyroidectomy including 1761 thyroid adenoma, 207 nodular goiter and 104 Hashimoto thyroiditis, the incidence of recurrent laryngeal nerve paralysis was 0.2%, 55 cases (2.6%) received secondary surgery. All the patients have no hypocalcemia or hemorrhage after operation. (2) Eighty-one cases of papillary carcinoma of the thyroid ( > 1 cm) and 60 cases of microcarcinoma. Unilateral thyroidectomy, contralateral near-total thyroidectomy and ipsilateral modified neck dissection were performed in unilateral papillary carcinoma of thyroid. Among the 9 cases of follicular carcinoma of thyroid, 7 were performed of near-total thyroidectomy without neck dissection, others were the same as papillary carcinoma. Bilateral total thyroidectomy and bilateral modified neck dissection were performed in 2 cases of the medullary thyroid cancer and 1 case of the undifferentiated thyroid cancer. By direct method the 5-year survival was 95.5% (64/67), and by Kaplan-Meier method, it was 98.0%. The treatment of microcarcinoma are multiple. There is no relapse or metastases in 60 cases of papillary thyroid microcarcinoma. The 5-year survival was 100.0%, 1 cases occurred recurrent laryngeal nerve paralysis in thyroid cancer. No hypocalcemia or hemorrhage. Eight case relapsed in 156 cases of thyroid carcinoma,3 cases died.</p><p><b>CONCLUSION</b>The correct surgical management for the patients with thyroid tumor should benefit for the prognosis and reduce the complications and the recurrence of the operation.</p>