Induction-concurrent chemoradiotherapy with or without sintilimab in patients with locoregionally advanced nasopharyngeal carcinoma in China (CONTINUUM): a multicentre, open-label, parallel-group, randomised, controlled, phase 3 trial.

BACKGROUND: Anti-PD-1 therapy and chemotherapy is a recommended first-line treatment for recurrent or metastatic nasopharyngeal carcinoma, but the role of PD-1 blockade remains unknown in patients with locoregionally advanced nasopharyngeal carcinoma. We assessed the addition of sintilimab, a PD-1 inhibitor, to standard chemoradiotherapy in this patient population. METHODS: This multicentre, open-label, parallel-group, randomised, controlled, phase 3 trial was conducted at nine hospitals in China. Adults aged 18-65 years with newly diagnosed high-risk non-metastatic stage III-IVa locoregionally advanced nasopharyngeal carcinoma (excluding T3-4N0 and T3N1) were eligible. Patients were randomly assigned (1:1) using blocks of four to receive gemcitabine and cisplatin induction chemotherapy followed by concurrent cisplatin radiotherapy (standard therapy group) or standard therapy with 200 mg sintilimab intravenously once every 3 weeks for 12 cycles (comprising three induction, three concurrent, and six adjuvant cycles to radiotherapy; sintilimab group). The primary endpoint was event-free survival from randomisation to disease recurrence (locoregional or distant) or death from any cause in the intention-to-treat population. Secondary endpoints included adverse events. This trial is registered with ClinicalTrials.gov (NCT03700476) and is now completed; follow-up is ongoing. FINDINGS: Between Dec 21, 2018, and March 31, 2020, 425 patients were enrolled and randomly assigned to the sintilimab (n=210) or standard therapy groups (n=215). At median follow-up of 41·9 months (IQR 38·0-44·8; 389 alive at primary data cutoff [Feb 28, 2023] and 366 [94%] had at least 36 months of follow-up), event-free survival was higher in the sintilimab group compared with the standard therapy group (36-month rates 86% [95% CI 81-90] vs 76% [70-81]; stratified hazard ratio 0·59 [0·38-0·92]; p=0·019). Grade 3-4 adverse events occurred in 155 (74%) in the sintilimab group versus 140 (65%) in the standard therapy group, with the most common being stomatitis (68 [33%] vs 64 [30%]), leukopenia (54 [26%] vs 48 [22%]), and neutropenia (50 [24%] vs 46 [21%]). Two (1%) patients died in the sintilimab group (both considered to be immune-related) and one (<1%) in the standard therapy group. Grade 3-4 immune-related adverse events occurred in 20 (10%) patients in the sintilimab group. INTERPRETATION: Addition of sintilimab to chemoradiotherapy improved event-free survival, albeit with higher but manageable adverse events. Longer follow-up is necessary to determine whether this regimen can be considered as the standard of care for patients with high-risk locoregionally advanced nasopharyngeal carcinoma. FUNDING: National Natural Science Foundation of China, Key-Area Research and Development Program of Guangdong Province, Natural Science Foundation of Guangdong Province, Overseas Expertise Introduction Project for Discipline Innovation, Guangzhou Municipal Health Commission, and Cancer Innovative Research Program of Sun Yat-sen University Cancer Center. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

[Mechanism of total flavonoids of Rhododendra simsii in alleviating ischemic brain injury].

This study explores the effect of total flavonoids of Rhododendra simsii(TFR) on middle cerebral artery occlusion(MCAO)-induced cerebral injury in rats and oxygen-glucose deprivation/reoxygenation(OGD/R) injury in PC12 cells and the underlying mechanism. The MCAO method was used to induce focal ischemic cerebral injury in rats. Male SD rats were randomized into sham group, model group, and TFR group. After MCAO, TFR(60 mg·kg~(-1)) was administered for 3 days. The content of tumor necrosis factor-α(TNF-α), interleukin-1(IL-1), and interleukin-6(IL-6) in serum was detected by enzyme-linked immunosorbent assay(ELISA). The pathological changes of brain tissue and cerebral infarction were observed based on hematoxylin and eosin(HE) staining and 2,3,5-triphenyltetrazolium chloride(TTC) staining. RT-qPCR and Western blot were used to detect the mRNA and protein levels of calcium release-activated calcium channel modulator 1(ORAI1), stromal interaction molecule 1(STIM1), stromal intera-ction molecule 2(STIM2), protein kinase B(PKB), and cysteinyl aspartate specific proteinase 3(caspase-3) in brain tissues. The OGD/R method was employed to induce injury in PC12 cells. Cells were randomized into the normal group, model group, gene silencing group, TFR(30 µg·mL~(-1)) group, and TFR(30 µg·mL~(-1))+gene overexpression plasmid group. Intracellular Ca~(2+) concentration and apoptosis rate of PC12 cells were measured by laser scanning confocal microscopy and flow cytometry. The effect of STIM-ORAI-regulated store-operated calcium entry(SOCE) pathway on TFR was explored based on gene silencing and gene overexpression techniques. The results showed that TFR significantly alleviated the histopathological damage of brains in MCAO rats after 3 days of admini-stration, reduced the contents of TNF-α, IL-1, and IL-6 in the serum, down-regulated the expression of ORAI1, STIM1, STIM2, and caspase-3 genes, and up-regulated the expression of PKB gene in brain tissues of MCAO rats. TFR significantly decreased OGD/R induced Ca~(2+) overload and apoptosis in PC12 cells. However, it induced TFR-like effect by ORAI1, STIM1 and STIM2 genes silencing. However, overexpression of these genes significantly blocked the effect of TFR in reducing Ca~(2+) overload and apoptosis in PC12 cells. In summary, in the early stage of focal cerebral ischemia-reperfusion injury and OGD/R-induced injury in PC12 cells TFR attenuates ischemic brain injury by inhibiting the STIM-ORAI-regulated SOCE pathway and reducing Ca~(2+) overload and inflammatory factor expression, and apoptosis.

[Protective effect of total flavonoids of Rhododendron simsii on focal cerebral ischemia-reperfusion injury through SOCE pathway in rats].

This paper explored the protective effect of total flavonoids of Rhododendron simsii(TFR) on focal cerebral ischemia-reperfusion injury(CIRI) in rats and its relationship with the store-operated calcium entry(SOCE) pathway regulated by stromal intera-ction molecule(STIM) and calcium release-activated calcium modulator(Orai).Rats were randomly assigned into the sham group, model(middle cerebral artery occlusion, MCAO) group, TFR(60 mg·kg~(-1)) group, TFR(60 mg·kg~(-1))+SOCE pathway inhibitor 2-aminoethoxydiphenyl borate(2-APB, 2.5 mg·kg~(-1)) group, and 2-APB(2.5 mg·kg~(-1)) group.The rats in the sham group and MCAO group were administrated with normal saline, and those in the TFR group and TFR+2-APB group were administrated with TFR(60 mg·kg~(-1)) by gavage for 14 days until sampling.The rats in the 2-APB group and TFR+2-APB group were intraperitoneally injected with 2-APB(2.5 mg·kg~(-1)) after operation.The levels of interleukin-1(IL-1), interleukin-6(IL-6), and tumor necrosis factor-alpha(TNF-α) in serum were measured by ELISA.The cerebral infarction and the pathological status of ischemic brain tissue were detected via TTC staining and HE staining, respectively.The protein and mRNA levels of STIM1, STIM2, Orai1, cysteinyl aspartate specific proteinase 3(caspase-3), and protein kinase B(PKB) in brain tissue were respectively determined by Western blot and RT-qPCR.The growth of brain neurons in each group was observed via immunofluorescence method.The results showed that compared with the MCAO group, TFR lowered the levels of IL-1, IL-6 and TNF-α in serum and the score of neurological function, ameliorated the pathological injury of brain tissue, and decreased the infarct size.Moreover, TFR up-regulated the mRNA and protein levels of STIM1, STIM2, Orai1, and PKB, down-regulated those of caspase-3 in brain tissue, and increased the double-labeled positive cells under fluorescence microscope.However, the above effects were significantly weakened by the addition of 2-APB, a SOCE inhibitor.The results suggested that TFR may play a protective role against focal cerebral ischemia-reperfusion injury by up-regulating the expression of SOCE-related signal molecules, promoting neurogenesis around the ischemic area, improving the survival state of neurons, and redu-cing the activity of inflammatory mediators.

Induction chemotherapy with lobaplatin and fluorouracil versus cisplatin and fluorouracil followed by chemoradiotherapy in patients with stage III-IVB nasopharyngeal carcinoma: an open-label, non-inferiority, randomised, controlled, phase 3 trial.

BACKGROUND: Cisplatin-based induction chemotherapy plus concurrent chemoradiotherapy in the treatment of patients with locoregionally advanced nasopharyngeal carcinoma has been recommended in the National Comprehensive Cancer Network Guidelines. However, cisplatin is associated with poor patient compliance and has notable side-effects. Lobaplatin, a third-generation platinum drug, has shown promising antitumour activity against several malignancies with less toxicity. In this study, we aimed to evaluate the efficacy of lobaplatin-based induction chemotherapy plus concurrent chemoradiotherapy over a cisplatin-based regimen in patients with locoregional, advanced nasopharyngeal carcinoma. METHODS: In this open-label, non-inferiority, randomised, controlled, phase 3 trial done at five hospitals in China, patients aged 18-60 years with previously untreated, non-keratinising stage III-IVB nasopharyngeal carcinoma; Karnofsky performance-status score of at least 70; and adequate haematological, renal, and hepatic function were randomly assigned (1:1) to receive intravenously either lobaplatin-based (lobaplatin 30 mg/m2 on days 1 and 22, and fluorouracil 800 mg/m2 on days 1-5 and 22-26 for two cycles) or cisplatin-based (cisplatin 100 mg/m2 on days 1 and 22, and fluorouracil 800 mg/m2 on days 1-5 and 22-26 for two cycles) induction chemotherapy, followed by concurrent lobaplatin-based (two cycles of intravenous lobaplatin 30 mg/m2 every 3 weeks plus intensity-modulated radiotherapy) or cisplatin-based (two cycles of intravenous cisplatin 100 mg/m2 every 3 weeks plus intensity-modulated radiotherapy) chemoradiotherapy. Total radiation doses of 68-70 Gy (for the sum of the volumes of the primary tumour and enlarged retropharyngeal nodes), 62-68 Gy (for the volume of clinically involved gross cervical lymph nodes), 60 Gy (for the high-risk target volume), and 54 Gy (for the low-risk target volume), were administered in 30-32 fractions, 5 days per week. Randomisation was done centrally at the clinical trial centre of Sun Yat-sen University Cancer Centre by means of computer-generated random number allocation with a block design (block size of four) stratified according to disease stage and treatment centre. Treatment assignment was known to both clinicians and patients. The primary endpoint was 5-year progression-free survival, analysed in both the intention-to-treat and per-protocol populations. If the upper limit of the 95% CI for the difference in 5-year progression-free survival between the lobaplatin-based and cisplatin-based groups did not exceed 10%, non-inferiority was met. Adverse events were analysed in all patients who received at least one cycle of induction chemotherapy. This trial is registered with the Chinese Clinical Trial Registry, ChiCTR-TRC-13003285 and is closed. FINDINGS: From June 7, 2013, to June 16, 2015, 515 patients were assessed for eligibility and 502 patients were enrolled: 252 were randomly assigned to the lobaplatin-based group and 250 to the cisplatin-based group. After a median follow-up of 75·3 months (IQR 69·9-81·1) in the intention-to-treat population, 5-year progression-free survival was 75·0% (95% CI 69·7-80·3) in the lobaplatin-based group and 75·5% (70·0 to 81·0) in the cisplatin-based group (hazard ratio [HR] 0·98, 95% CI 0·69-1·39; log-rank p=0·92), with a difference of 0·5% (95% CI -7·1 to 8·1; pnon-inferiority=0·0070). In the per-protocol population, the 5-year progression-free survival was 74·8% (95% CI 69·3 to 80·3) in the lobaplatin-based group and 76·4% (70·9 to 81·9) in the cisplatin-based group (HR 1·04, 95% CI 0·73 to 1·49; log-rank p=0·83), with a difference of 1·6% (-6·1 to 9·3; pnon-inferiority=0·016). 63 (25%) of 252 patients in the lobaplatin-based group and 63 (25%) of 250 patients in the cisplatin-based group had a progression-free survival event in the intention-to-treat population; 62 (25%) of 246 patients in the lobaplatin-based group and 58 (25%) of 237 patients in the cisplatin-based group had a progression-free survival event in the per-protocol population. The most common grade 3-4 adverse events were mucositis (102 [41%] of 252 in the lobaplatin-based group vs 99 [40%] of 249 in the cisplatin-based group), leucopenia (39 [16%] vs 56 [23%]), and neutropenia (25 [10%] vs 59 [24%]). No treatment-related deaths were reported. INTERPRETATION: Lobaplatin-based induction chemotherapy plus concurrent chemoradiotherapy resulted in non-inferior survival and fewer toxic effects than cisplatin-based therapy. The results of our trial indicate that lobaplatin-based induction chemotherapy plus concurrent chemoradiotherapy might be a promising alternative regimen to cisplatin-based treatment in patients with locoregional, advanced nasopharyngeal carcinoma. FUNDING: National Science and Technology Pillar Program, International Cooperation Project of Science and Technology Program of Guangdong Province, Planned Science and Technology Project of Guangdong Province, and Cultivation Foundation for the Junior Teachers at Sun Yat-sen University. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Two Metal Complexes: Selective Detection of Fe3+ Ion and Promotion Activity on Mesenchymal Stem Cells Differentiate Into Vascular Endothelial Cells.

With the aid of 1,2-bis(4-pyridyl)ethane (bpee), a nitrogen-donor ligand and 1,3,5-tris(carboxymethoxy)benzene (H3TCMB), a tripodal ether-connector tricarboxylate ligand, two novel transition metal coordination polymers (CPs) have been synthesized via the reaction of Zn(NO3)2·6H2O or Cu(NO3)2·3H2O with the ligands of H3TCMB and bpee ligands with similar reactions under slightly distinct temperatures (80℃ for 1 and 120℃ for 2), and their chemical formula are [Cu4(TCMB)2(bpee)2(µ3-OH)2(H2O)2]n·12nH2O (1) and [Zn4(TCMB)2(bpee)2(µ3-OH)2(H2O)2]n·12nH2O (2). Complex 2 can be utilized as a super sensitive fluorescence quenching sensor to determine the Fe3+ ions. The effect of these two compounds on the differentiation of mesenchymal stem cells (MSCs) into the cells of vascular endothelial was further explored.

Efficacy and Safety of Locoregional Radiotherapy With Chemotherapy vs Chemotherapy Alone in De Novo Metastatic Nasopharyngeal Carcinoma: A Multicenter Phase 3 Randomized Clinical Trial.

Importance: The role of locoregional radiotherapy in patients with de novo metastatic nasopharyngeal carcinoma (mNPC) is unclear. Objective: To investigate the efficacy and safety of locoregional radiotherapy in de novo mNPC. Design, Setting, and Participants: Patients with biopsy-proven mNPC, who demonstrated complete or partial response (RECIST v1.1) following 3 cycles of cisplatin and fluorouracil chemotherapy, were enrolled. Eligible patients were randomly assigned (1:1) to receive either chemotherapy plus radiotherapy or chemotherapy alone. Overall, 126 of 173 patients screened were eligible to the study, and randomized to chemotherapy plus radiotherapy (n = 63) or chemotherapy alone (n = 63). Median (IQR) follow-up duration was 26.7 (17.2-33.5) months. Interventions: The chemotherapy regimens were fluorouracil continuous intravenous infusion at 5 g/m2 over 120 hours and 100 mg/m2 intravenous cisplatin on day 1, administered every 3 weeks for 6 cycles. Patients assigned to the chemotherapy plus radiotherapy group received intensity-modulated radiotherapy (IMRT) after chemotherapy. Main Outcomes and Measures: The primary end point of the study was overall survival (OS). The secondary end point was progression-free survival (PFS) and safety. Results: Overall, 126 patients were enrolled (105 men [83.3%] and 21 women [16.7%]; median [IQR] age, 46 [39-52] years). The 24-month OS was 76.4% (95% CI, 64.4%-88.4%) in the chemotherapy plus radiotherapy group, compared with 54.5% (95% CI, 41.0%-68.0%) in the chemotherapy-alone group. The study met its primary end point of improved OS (stratified hazard ratio [HR], 0.42; 95% CI, 0.23-0.77; P = .004) in favor of chemotherapy plus radiotherapy. Progression-free survival was also improved in the chemotherapy plus radiotherapy group compared with the chemotherapy-alone group (stratified HR, 0.36; 95% CI, 0.23-0.57). No significant differences in acute hematological or gastrointestinal toxic effects were observed between the treatment arms. The frequency of acute grade 3 or higher dermatitis, mucositis, and xerostomia was 8.1%, 33.9%, and 6.5%, respectively, in the chemotherapy plus radiotherapy group. The frequency of late severe grade 3 or higher hearing loss and trismus was 5.2% and 3.4%, respectively, in the chemotherapy plus radiotherapy group. Conclusions and Relevance: In this randomized clinical trial, radiotherapy added to chemotherapy significantly improved OS in chemotherapy-sensitive patients with mNPC. Trial Registration: ClinicalTrials.gov Identifier: NCT02111460.

Establishment and validation of M1 stage subdivisions for de novo metastatic nasopharyngeal carcinoma to better predict prognosis and guide treatment.

BACKGROUND: To better manage patients with de novo metastatic NPC (mNPC) including easily identifying individuals' survival outcomes and accurately choosing the most suitable treatment. MATERIALS AND METHODS: Three independent cohorts of mNPC patients (a training set of n = 462, an internal prospective validation set of n = 272 and an external prospective validation set of n = 243) were studied. The radiological characteristics of distant metastases, including number of metastatic locations, number of metastatic lesions and size of metastatic lesions, were carefully defined based on imaging data. These three factors and other potential prognostic factors were comprehensively analysed and were further integrated into new subdivisions of stage M1 using a Cox proportional hazards model. RESULTS: We successfully subdivided the M1 stage into three categories: M1a, oligo metastasis without liver involvement; M1b, multiple metastases without liver involvement; and M1c, liver involvement irrespective of metastatic lesions. The 3-year overall survival ranged from 54.5% to 72.8%, from 34.3% to 41.6% and from 22.6.0%-23.6% for M1a, M1b and M1c, respectively (P < 0.001). Systemic chemotherapy combined with radical loco-regional radiotherapy may benefit patients in M1a and M1b, not in M1c. Further aggressive treatment of metastatic lesions based on systemic chemotherapy and definitive loco-regional radiotherapy showed no survival benefit, even for patients in M1a (P > 0.05). CONCLUSION: The subdividing of M1 provided promising prognostic value and could aid clinicians in choosing the most suitable treatment for de novo mNPC patients.

Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy.

BACKGROUND: Gross target volume of primary tumor (GTV-P) is very important for the prognosis prediction of patients with nasopharyngeal carcinoma (NPC), but it is unknown whether the same is true for locally advanced NPC patients treated with intensity-modulated radiotherapy (IMRT). This study aimed to clarify the prognostic value of tumor volume for patient with locally advanced NPC receiving IMRT and to find a suitable cut-off value of GTV-P for prognosis prediction. METHODS: Clinical data of 358 patients with locally advanced NPC who received IMRT were reviewed. Receiver operating characteristic (ROC) curves were used to identify the cut-off values of GTV-P for the prediction of different endpoints [overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and disease-free survival (DFS)] and to test the prognostic value of GTV-P when compared with that of the American Joint Committee on Cancer T staging system. RESULTS: The 358 patients with locally advanced NPC were divided into two groups by the cut-off value of GTV-P as determined using ROC curves: 219 (61.2%) patients with GTV-P ≤46.4 mL and 139 (38.8%) with GTV-P >46.4 mL. The 3-year OS, LRFS, DMFS, and DFS rates were all higher in patients with GTV-P ≤46.4 mL than in those with GTV-P > 46.4 mL (all P < 0.05). Multivariate analysis indicated that GTV-P >46.4 mL was an independent unfavorable prognostic factor for patient survival. The ROC curve verified that the predictive ability of GTV-P was superior to that of T category (P < 0.001). The cut-off values of GTV-P for the prediction of OS, LRFS, DMFS, and DFS were 46.4, 57.9, 75.4 and 46.4 mL, respectively. CONCLUSION: In patients with locally advanced NPC, GTV-P >46.4 mL is an independent unfavorable prognostic indicator for survival after IMRT, with a prognostic value superior to that of T category.

Association of miR-146a gene polymorphism with risk of nasopharyngeal carcinoma in the central-southern Chinese population.

This case-control study focused on estimating the association between miR-146a polymorphism and risk of nasopharyngeal carcinoma (NPC) in central-south China. In total, 160 patients with NPC and 200 healthy controls in central-south China were genotyped using polymerase chain reaction-restriction fragment length polymorphism assay. Chi-square test was used to assess the different distribution of miR-146a polymorphism between NPC patients and controls; and logistic regression analysis was applied to analyze the associations between miR-146a polymorphism with cancer risk in different contrast models. Significant differences between NPC patients and controls were found in genotype (P=0.033 for GG versus CG versus CC; and odds ratio (OR)=0.568, 95% confidence interval (CI)=0.354-0.912, P=0.019 for CG versus CC; and OR=0.503, 95% CI=0.261-0.971, P=0.041 for CG versus CC; and OR=0.564, 95% CI=0.360-0.884, P=0.012 for GG+CG versus CC, respectively) and allelic analysis (P=0.025 for G versus C). Our findings suggested that polymorphism of mir-146a was associated with NPC in the central-southern Chinese population.

Association study between miR-149 gene polymorphism and nasopharyngeal carcinoma.

Association studies between single-nucleotide polymorphism (SNP) rs2292832 on miR-149 gene and cancer risk have been previously analyzed in several types of cancer. The aim of this study was to evaluate the association between miR-149 polymorphism and risk of nasopharyngeal carcinoma (NPC). miR-149 gene polymorphism was genotyped using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) in 158 patients with NPC and 242 healthy individuals. Associations with cancer risk and clinicopathological characteristics were analyzed by χ2 test. No significant difference was observed for miR-149 gene polymorphism in NPC patients and healthy controls in either genotype (P=0.427 for CC vs. CT vs. TT, P=0.247 for CT vs. TT and P=0.323 for CC vs. TT, respectively) or allelic analysis (P=0.216). No significant difference was noted between the genotypes and the clinicopathological parameters examined with the exception of clinical stage. A significantly higher CC distribution in clinical stage I-II compared with III-IV was observed under the dominant model (CC vs. CT vs. TT, P=0.026) and the co-dominant model (CC vs. TT, P=0.030). The results of this study suggested that the CC genotype of miR-149 contributes to the progression and development, rather than the initiation of NPC.

Association between PIN1 promoter polymorphisms and risk of nasopharyngeal carcinoma.

Peptidylprolyl cis/trans isomerase, NIMA-interacting 1 (PIN1) plays an important role in cell transformation and oncogenesis. Association between PIN1 promoter polymorphisms and cancer risk was reported in several cancers. This study aimed to evaluate the association between two single nucleotide polymorphisms (SNPs, -667T>C, rs2233679 and -842G>C, rs2233678) on PIN1 promoter and risk of nasopharyngeal carcinoma (NPC). The two SNPs were genotyped using polymerase chain reaction-restriction fragment length polymorphism in a total of 334 native Chinese subjects consisting of 178 cases and 156 controls. The results indicated that the -667CT heterozygote and -667CC homozygote exhibited a significantly decreased risk of nasopharyngeal carcinoma when compared with -667TT homozygote (OR = 0.639, 95% CI = 0.452-0.903, p = 0.011 for -667CT; and OR = 0.441, 95% CI = 0.213-0.915, p = 0.038 for -667CC, respectively). In the -842G>C polymorphism, compared with -842GG homozygote, only -842CG heterozygote but not -842CC homozygote had a significantly decreased risk of nasopharyngeal carcinoma (OR = 0.465, 95% CI = 0.249-0.871, p = 0.010). Genotype in the two SNPs in patients showed no significant associations with the clinicopathologic features examined. Our study showed that the minor genotypes of PIN1 promoter (-667CT, -667CC and -842CG) were associated with decreased risk of NPC in a Chinese population, suggested that PIN1 promoter polymorphisms might play an important role in NPC carcinogenesis.

[Effect of DNA-PKcs antisense oligodeoxynucleotides on radiosensitivity of nasopharyngeal carcinoma cell lines with different p53 function statuses].

BACKGROUND & OBJECTIVE: DNA-dependent protein kinase (DNA-PK) can repair DNA double-strand break. This study was to observe the effect of DNA-PKcs antisense oligodeoxynucleotides (ASODN) on the radiosensitivity of nasopharyngeal carcinoma (NPC) cell lines with normal or abnormal p53 functions. METHODS: DNA-PKcs ASODN was transfected into CNE-1 and CNE-1-wtp53 cells. These cells were irradiated with 0, 0.5, 1, 2, 4, 6, or 8 Gy X-ray. Cell survival was determined by clonogenic assay. The parameters D0, Dq, and N for the single-hit multitarget model and the parameters alpha, beta, alpha/beta, and SF2 for the linear-quadratic model were calculated to evaluate the changes of radiosensitivity. RESULTS: The alpha values before DNA-PKcs ASODN transfection were 0.03 in CNE-1 cells and 0.05 in CNE-1-wtp53 cells; the alpha values after transfection were 0.04 in CNE-1 cells and 0.27 in CNE-1-wtp53 cells. The SF2 before transfection were 0.73 in CNE-1 cells and 0.50 in CNE-1-wtp53 cells; the SF2 after transfection were 0.45 in CNE-1 cells and 0.21 in CNE-1-wtp53 cells. The D0 before transfection were 2.08 Gy in CNE-1 cells and 1.13 Gy in CNE-1-wtp53 cells; the D0 after transfection were 1.07 Gy in CNE-1 cells and 0.83 Gy in CNE-1-wtp53 cells. The Dq before transfection were 2.04 Gy in CNE-1 cells and 1.36 Gy in CNE-1-wtp53 cells; the Dq after transfection were 1.24 Gy in CNE-1 cells and 0.73 Gy in CNE-1-wtp53 cells. The parameter alpha of CNE-1 cells was increased after DNA-PKcs ASODN transfection, but the parameters SF2, D0, and Dq were decreased after transfection. CONCLUSION: DNA-PKcs ASODN could enhance the radiosensitivity of CNE-1 cells regardless of p53 function status.

DNA-dependent protein kinase activity and radiosensitivity of nasopharyngeal carcinoma cell lines CNE1/CNE2.

The present study investigated the relationship between DNA-dependent protein kinase (DNA-PK) and radiosensitivity of nasopharyngeal carcinoma (NPC) cell lines. The dose-survival relationship for NPC cell lines, CNE1 and CNE2, was analyzed using clonogenic formation assay, the activity of DNA-PK of the two cell lines was measured using the Signa TECT DNA-PK assay kit, and the localization and expression of Kus (a heterodimer) and DNA-PKcs protein in CNE1 and CNE2 before irradiation and 15 min, 1 h, 6 h, 12 h, 24 h after 4 Gy irradiation were analyzed by immunofluorescence, laser scanning confocal microscope (LSCM) and Western blot. The results showed that the surviving fraction of CNE1 was higher than that of CNE2 at each dose. The DNA-PK activity of CNE1 was also significantly higher than that of CNE2 before and after irradiation (P<0.05), while the expression of total Ku70/Ku80 in CNE1 and CNE2 had no significant difference. Increasing translocation of Ku70 and Ku80 from the cytoplasm to the nuclei in the two cell lines was observed with increase of irradiation time as detected by Western blot, and the immunofluorescence of the DNA-PK complex subunits showed greater nuclear translocation in CNE1 than CNE2 after irradiation. The results suggest that the relatively higher radio-resistance of CNE1 correlates with the higher activity of DNA-PK as compared to that of more radiosensitive CNE2 (or lower radio-resistance) before and after irradiation. Thus, DNA-PK activity may be a useful predictor of radiosensitivity of NPC.

[Correlation of DNA-PK activity with anti-cancer drug-sensitivity in human gliomas].

OBJECTIVE: To investigate the relationship between DNA-dependent protein kinase (DNA-PK) activity and anti-cancer drug sensitivity in human glioma tissues. METHODS: Human glioma specimens were primarily cultured and its sensitivity to several anti-cancer drugs were evaluated by MTT assay. Nuclear protein was extracted from the glioma sample of the same patient and its DNA-PK activity was determined by a biotinylated DNA-PK assay with p53-derived peptide as a specific substrate. RESULTS: DNA-PK activity varied widely among these glioma samples. Of all 36 samples, 16 showed higher DNA-PK activity (relative activity > or = 0.40) and 20 samples with lower DNA-PK activity (relative activity < 0.40). The gliomas sensitive to DDP and VCR as evaluated by inhibition rate (IR > or = 50%) under plasma peak concentration (PPC) showed lower DNA-PK activity than the resistant ones (IR < 50%) (t = -3.445, P < 0.01). Furthermore, the gliomas with higher DNA-PK activity showed lower inhibition rate (IR < 50%) than those with lower DNA-PK activity ones (t = -2.145, P < 0.05). CONCLUSION: DNA-PK activity is significantly associated with anti-cancer drug sensitivity to DDP and VCR in human gliomas. DNA-PK activity could be used as a new biomarker for the chemotherapy sensitivity of human gliomas.

The effect of p21 antisense oligodeoxynucleotides on the radiosensitivity of nasopharyngeal carcinoma cells with normal p53 function.

OBJECTIVE: p21(WAF1/CIP1) is transcriptionally activated by p53 and is required for G1 to S phase progression. p21 plays a critical role in DNA repair after DNA damage. Thus, cells with defective p21 may result in an enhancement of radiation induced apoptosis and improved radiosensitivity. We tested the hypothesis that p21 antisense oligodeoxynucleotides (p21 AS ODNs) can be used to reduce p21 expression level and increase radiosensitivity in CNE-1-wtp53 nasopharyngeal carcinoma cell line with normal p53 function. METHODS AND MATERIALS: The p21 antisense oligodeoxynucleotides (p21 AS ODNs) and the random control oligodeoxynucleotides (p21 RD ODNs) were synthesized. p21 AS ODNs sequence: 5'-TGTCATGCTGGTCTGCCGCC-3'; p21 RD ODNs sequence: 5'-CCGGTGAACGAGCGAGCACA-3'. p21 AS ODNs and p21 RD ODNs were transfected into CNE-1-wtp53 nasopharyngeal carcinoma cell line. The protein expression levels of P21 were evaluated using Western blotting analysis. Cell cycle progression and apoptotic cells were assessed by flow cytometric analysis. The clonogenic survival assay was performed to determine the survival fraction. The parameters D0, Dq, and N for the single-hit multitarget model and the parameters alpha, beta, alpha/beta, and SF2 for the linear-quadratic model were calculated. BALB/c nude mice were used to investigate the effect of p21 AS ODNs on the radiosensitivity of nasopharyngeal xenografts in vivo. RESULTS: p21 AS ODNs were detected mainly in plasma with fluorescence microscopy investigation. P21 protein level dramatically decreased and the amount of apoptotic cells increased in p21 AS ODNs transfected cells than in p21 RD ODNs transfected cells after irradiation. The percentage of G1 arrest decreased in p21 AS ODNs transfected cells 24 h after radiation, then G2 arrest decreased 48 h after radiation. The values of D0, Dq, SF2 decreased and alpha value increased in p21 AS ODNs transfected cells than in control cells. The inhibition rate in tumor xenografts exposed to X ray of 10 Gy alone was 39.1%, while it was 51.4% in xenografts injected with p21 AS ODNs before exposure to radiation. Unfortunately, there was no significant difference between these two groups (P < 0.05). CONCLUSION: p21 Antisense oligodeoxynucleotides led to inhibition of P21 protein expression, loss of G1 arrest, increase of apoptosis in CNE-1-wtp53 nasopharyngeal carcinoma cell line in vitro and inhibited tumor growth in vivo. Antisense oligodeoxynucleotides may become a promising strategy to enhance radiosensitivity in nasopharyngeal carcinoma cells with normal p53 function.