Identification and validation of cuproptosis-related LncRNA signatures as a novel prognostic model for head and neck squamous cell cancer.

BACKGROUND: Head and neck squamous cell cancer (HNSCC) is a common malignant cancer. We aimed to explore prognostic cuproptosis-related lncRNAs (CRLs) and prognostic risk models for HNSCC. METHODS: The transcriptome profiles and clinical data were obtained from the TCGA database, and 19-cuproptosis-related genes (CRGs) were acquired from previous studies. Then, the prognostic model based on seven CRLs was established. We analysed its value to evaluate the prognosis, drug sensitivity, and tumour immune functions of patients with HNSCC. Finally, we used quantitative reverse transcription polymerase chain reaction (qRT‒PCR) to validate the seven CRLs. RESULTS: We established a 7-CRL signature. Kaplan‒Meier (K-M) curve analysis demonstrated a significantly preferable prognosis in the low-risk group. Multivariate Cox regression analysis revealed that the risk score could serve as an independent prognostic factor. Nomogram, ROC curve, and principal component analysis indicated that the signature presented significant predictive capability. Moreover, most of the high-risk group showed lower levels of IC50 for certain chemotherapy drugs, such as cisplatin, cytarabine, docetaxel, doxorubicin, etoposide, gemcitabine, methotrexate, paclitaxel, and dasatinib. Finally, the expression of AP001372.2, MIR9-3HG, AL160314.2, POLH-AS1, and AL109936.2 was upregulated, while AC090587.1 and WDFY3-AS2 were downregulated in HNSCC cell lines compared with normal cell lines by qRT‒PCR. CONCLUSIONS: The 7-CRL signature was presented to be a novel biomarker for predicting prognosis for HNSCC.

The global, regional, national burden of laryngeal cancer and its attributable risk factors (1990-2019) and predictions to 2035.

OBJECTIVE: We aim to report the incidence, mortality and disability-adjusted life years (DALYs) between 1990 and 2019 and provide predictions to 2035. METHODS: We use estimates from Global Burden of Disease, Injuries and Risk Factors Study 2019 to analyse the incidence, mortality and DALYs. RESULTS: In 2019, there were more than 209,149 incidence cases, with age-standardised rates (ASRs) of 2.5. Laryngeal cancer accounted for 123,356 death cases, with ASRs of 1.5. Laryngeal cancer was also responsible for 3.26 million (3,034,634 to 3,511,354) DALYs, with ASRs of 38.8 (36.1 to 41.8). In 2019, Central Europe had the highest age-standardised incidence rate. At the national level, the highest incidence rate was observed in Mongolia. Total number and rate were significantly higher among males than females across all age groups. DALYs were attributable to Alcohol use, Smoking, Occupational exposure to sulfuric acid and asbestos. The age-standardised incidence rates in seven GBD regions and 59 countries are projected to increase between 2019 and 2035. CONCLUSIONS: Despite the current and predicted decline in age-standardised incidence globally, the absolute number of estimates continue to increase. Prevention programmes should concentrate on modifiable risk factors, especially among the males across all age groups.

Neferine sensitized Taxol-resistant nasopharygeal carcinoma to Taxol by inhibiting EMT via downregulating miR-130b-5p.

Taxol resistance led to the poor survival prognosis in advanced nasopharyngeal carcinoma (NPC). Epithelial-mesenchymal transition (EMT) plays an important role in tumor chemoresistance. Neferine (NEF) is found to sensitize the cancer cells to chemotherapeutic agents, but its effects and mechanisms on NPC Taxol resistance is unclear. In this study, we discovered that Taxol-resistant cell lines 5-8F/Taxol and CNE-1/Taxol had the greater ability to metastasis and the higher expression of EMT markers. Then we found that NEF could inhibit the viability and EMT process in the Taxol-resistant cell lines. Furthermore, we confirmed that NEF could augment therapeutic efficacy of Taxol on NPC Taxol-resistant cell lines. Further through Microarray based analysis, we found that miR-130b-5p was stably down-regulated after treating 5-8F/Taxol with NEF. Later we verified that up-regulation of miR-130b-5p could not only promote the EMT-related migration/invasion, but also impair the inhibition effects of NEF on the EMT-associated metastatic ability and the chemotherapy resistance to Taxol. In conclusion, our results firstly suggested that NEF may enhanced Taxol sensitivity in NPC Taxol-resistant cell lines through inhibition of EMT which mediated by miR-130b-5p downregulation in vitro and in vivo. NEF may be used as a Taxol sensitizer in chemotherapy of NPC.

The role of Caspase-1/GSDMD-mediated pyroptosis in Taxol-induced cell death and a Taxol-resistant phenotype in nasopharyngeal carcinoma regulated by autophagy.

Taxol has been widely used as a first-line chemotherapeutic agent for the treatment of advanced nasopharyngeal carcinoma (NPC). However, acquired drug resistance has caused great difficulties in clinical treatment. Pyroptosis is a newly discovered programmed cell death pathway, and Caspase-1 and gasdermin D (GSDMD) play key roles in driving canonical pyroptosis. Increasing evidence suggests that pyroptosis is associated with the development of cancer; however, the function and mechanism of pyroptosis in NPC remain obscure. In this study, we observed that Taxol treatment caused pyroptotic cell death, along with activation of Caspase-1 and maturation of IL-1ß, as well as cleavage of GSDMD, which is the canonical pyroptosis executor. Furthermore, Taxol-induced pyroptotic cell death could be suppressed by Caspase-1 inhibitor (Z-YVAD-FMK) and GSDMD knockout. Moreover, NPC parental cells demonstrated higher levels of pyroptosis than Taxol-resistant cells, and pyroptosis mediated by Caspase-1/GSDMD suppression induced by a Caspase-1 inhibitor and GSDMD knockout could induce a Taxol-resistant phenotype in vitro and in vivo. By transfecting an siRNA targeting Beclin-1 into NPC Taxol-resistant cells, we discovered that autophagy could negatively regulate pyroptosis by inhibiting Caspase-1/GSDMD activation. Taken together, our results indicated that Caspase-1/GSDMD mediated Taxol-induced pyroptosis and a Taxol-resistant phenotype in NPC cell lines, which may be regulated by autophagy. Thus, we provide novel insight into the mechanisms of Taxol-induced cell death and a promising approach to improve the therapeutic outcomes of patients with advanced NPC.

Bidirectional Phase Transformations in Multi-Principal Element Alloys: Mechanisms, Physics, and Mechanical Property Implications.

The emergence of multi-principal element alloys (MPEAs) heralds a transformative shift in the design of high-performance alloys. Their ingrained chemical complexities endow them with exceptional mechanical and functional properties, along with unparalleled microscopic plastic mechanisms, sparking widespread research interest within and beyond the metallurgy community. In this overview, a unique yet prevalent mechanistic process in the renowned FeMnCoCrNi-based MPEAs is focused on: the dynamic bidirectional phase transformation involving the forward transformation from a face-centered-cubic (FCC) matrix into a hexagonal-close-packed (HCP) phase and the reverse HCP-to-FCC transformation. The light is shed on the fundamental physical mechanisms and atomistic pathways of this intriguing dual-phase transformation. The paramount material parameter of intrinsic negative stacking fault energy in MPEAs and the crucial external factors c, furnishing thermodynamic, and kinetic impetus to trigger bidirectional transformation-induced plasticity (B-TRIP) mechanisms， are thorougly devled into. Furthermore, the profound significance of the distinct B-TRIP behavior in shaping mechanical properties and creating specialized microstructures c to harness superior material characteristics is underscored. Additionally, critical insights are offered into key challenges and future striving directions for comprehensively advancing the B-TRIP mechanism and the mechanistic design of next-generation high-performing MPEAs.

Downward trends in the global burden of congenital complete hearing loss in children younger than five years from 1990 to 2030.

Background: The global epidemiological data on congenital hearing loss in children is sparse. We aimed to analyse the trends in the burden of complete hearing loss caused by congenital birth defects in children younger than five years from 1990 to 2030. Methods: Using data from the Global Burden of Disease (GBD) Study 2019, we reported the counts and rates of prevalence and years lived with disability (YLD) by age, sex, and sociodemographic index (SDI). We also forecasted the prevalence rates until 2030 through the autoregressive integrated moving average (ARIMA) and Bayesian age-period-cohort (BAPC) models. Results: We observed a global prevalence rate of 15.4 (95% uncertainty interval (UI) = 5.8 to 33.8) and a YLD rate of 3.3 (95% UI = 1.1 to 7.1) per 100 000 population in 2019, with both showing downward trends from 1990 to 2019. Regionally, Oceania had the highest prevalence (47.2; 95% UI = 18.8 to 96.6) and YLD (10; 95% UI = 3.2 to 22.8) rates, while Central Europe had the lowest rates. Nationally, the prevalence (85.0; 95% UI = 36.8 to 166.8) and YLD (17.9; 95% UI = 6.6 to 36.9) rates were highest in Myanmar and lowest in Peru. Only the United States of America (2.6%; 95% UI = -4.6 to 14.4) and Norway (0.6%; 95% UI = -6.7 to 16.2) showed upward trends. Compared to girls, the prevalence and YLD rates were higher for boys at global, regional, and five SDI quintile levels, except for Eastern Sub-Saharan Africa. At the global level, downward trends were predicted in prevalence rates from 2019 to 2030 between boys and girls. Conclusions: Although the global burden of childhood congenital complete hearing loss showed inequalities across locations, sexes, and age groups, we found decreases in the global prevalence rates between 1990 and 2019 and predicted decreases from 2019 to 2030. Better prevention of infectious aetiologies, improving genetic diagnoses, and hearing restoration could alleviate this burden.

Genomic methylation profiling combined with gene expression microarray reveals the aberrant methylation mechanism involved in nasopharyngeal carcinoma taxol resistance.

Taxol is a first-line chemoagent used for treatment of nasopharyngeal carcinoma (NPC). A major obstacle to achieving successful treatment is the development of cellular taxol drug resistance. Aberrant DNA methylation has been recognized to be associated with the transcriptional inactivation of genes related to cancer drug resistance development. To identify the mechanism of DNA methylation involved in NPC taxol resistance, we applied a genome-wide DNA methylation microarray assay to reveal methylation alteration in taxol-resistant NPC cell lines (CNE-1/taxol, 5-8F/taxol, HNE-2/taxol) established previously in our laboratory. Combining with gene expression microarray, we identified drug resistance-associated genes in taxol-resistant cell lines. We also investigated the coeffect of taxol and the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-aza-dC) to confirm the involvement of DNA methylation. The methylation profiling revealed differential patterns between the drug-sensitive and -resistant cell lines. As a result, taxol-resistant cell lines were detected to be globally hypermethylated. Forty-eight differentially methylated genes (30 hypermethylated and 18 hypomethylated) were further identified commonly in the three taxol-resistant cell lines. Six of them (DLC1, CHFR, ABCC5, PEG10, ERBB2, and GSTP1) were independently confirmed to contribute to taxol resistance by both methylation-specific PCR and quantitative real-time PCR. Finally, we conclude that DNA methylation is closely correlated with taxol drug resistance in NPC cells. Combined analysis of DNA methylation and gene expression may enable the discovery of new therapeutic targets and prognostic biomarkers of cancers. Furthermore, DNA methylation inhibitors can reverse chemoresistance and prevent the development of acquired drug resistance.

The global, regional, national burden of nasopharyngeal cancer and its attributable risk factors (1990-2019) and predictions to 2035.

We aim to report the latest incidence, mortality, and disability-adjusted life-years (DALYs) between 1990 and 2019, by age, sex, sociodemographic index (SDI), and provide predictions to 2035. We use estimates from Global Burden of Disease, Injuries, and Risk Factors Study 2019 to analyze the incidence, mortality, and DALYs. All the estimates were shown as counts and age-standardized rates (ASR). In 2019, there were more than 176,501 (156,046 to 199,917) incidence cases, with ASRs of 2.1 (1.9 to 2.4). Nasopharyngeal cancer (NPC) accounted for 71,610 (65,442 to 77,625) deaths, with ASRs of 0.9 (0.8 to 0.9). NPC was also responsible for 2.34 million (2,139,753 to 2,536,657) DALYs, with ASRs of 28.0 (25.7 to 30.4). The count of all the new cases increased from 1990 to 2019. At the regional level, the highest age-standardized incidence rates were found in East Asia, the highest age-standardized death and DALY rates were shown in Southeast Asia. At the national level, the age-standardized incidence rates were highest in Singapore, and the age-standardized death and DALY rates were highest in Malaysia. The total numbers and rates of all the estimates were significantly higher among males than females across most of the age groups. The considerable burden of NPC was attributable to alcohol use, smoking, and occupational exposure to formaldehyde. A total of six GBD regions and 88 countries are projected to experience an increase in NPC ASRs between 2019 and 2035, respectively. Despite the current decline in age-standardized mortality and DALY rates globally, the age-standardized incidence rate has increased from 1990 to 2019, and continues to increase between 2020 and 2035, indicating that nasopharyngeal cancer remains a major health challenge worldwide. Prevention strategies should focus on modifiable risk factors, especially among males in East Asia.

The global, regional and national burden of stomach cancer and its attributable risk factors from 1990 to 2019.

We aimed to estimate the incidence, mortality, and disability-adjusted life-years (DALYs) of stomach cancer at the global, regional, and national levels. Stomach cancer resulted in 1.3 million (1.2-1.4 million) incident cases, 9.5 hundred thousand (8.7-10.4 hundred thousand) deaths, and 22.2 million (20.3-24.1 million) DALYs in 2019. The age-standardized incidence rate, death rate and DALY rate were 15.6 (14.1-17.2), 11.9 (10.8-12.8), and 268.4 (245.5-290.6) per 100,000 person-years, respectively. Between 1990 and 2019, the global age-standardized incidence rate, death rate, and DALY rate decreased by - 30.5% (- 36.7 to - 22.9), - 41.9% (- 47.2 to - 36.3), and - 45.6% (- 50.8 to - 39.8), respectively. In 2019, most of the global numbers of incidence, death and DALYs were higher among males than females. A considerable burden of stomach cancer was attributable to smoking and a high-sodium diet. Although the global age-standardized incidence and death rates have decreased, continued growth in absolute numbers in some regions, especially in East Asia, poses a major global public health challenge. To address this, public health responses should be tailored to fit each country's unique situation. Primary and secondary prevention strategies with increased effectiveness are required to reduce the incidence and mortality of stomach cancer, particularly in populations with a high disease burden.

Optically modulated magnetic resonance of erbium implanted silicon.

Er implanted Si is a candidate for quantum and photonic applications; however, several different Er centres are generated, and their symmetry, energy level structure, magnetic and optical properties, and mutual interactions have been poorly understood, which has been a major barrier to the development of these applications. Optically modulated magnetic resonance (OMMR) gives a spectrum of the modulation of an electron paramagnetic resonance (EPR) signal by a tuneable optical field. Our OMMR spectrum of Er implanted Si agrees with three independent measurements, showing that we have made the first measurement of the crystal field splitting of the 4I13/2 manifold of Er implanted Si, and allows us to revise the crystal field splitting of the 4I15/2 manifold. This splitting originates from a photoluminescence (PL) active O coordinated Er centre with orthorhombic C2v symmetry, which neighbours an EPR active O coordinated Er centre with monoclinic C1h symmetry. This pair of centres could form the basis of a controlled NOT (CNOT) gate.

[Genomic instability in nasopharyngeal carcinoma].

OBJECTIVE: To evaluate the effect of genomic instability on prognostics in nasopharyngeal carcinoma. METHODS: Genomic instability was assessed by inter-simple sequence repeats polymerase chain reaction (inter-SSR PCR) in 38 patients with nasopharyngeal carcinoma. Characterization and verification of band alterations shared in different tumors were carried out by sequencing and nest PCR. RESULTS: Thirty-one (81.6%) of the 38 patients showed genomic altercations, and genomic instability index ranged 0 to 16.2 percent. A gain-based genomic damage shared in 6 tumors was identified on chromosome 6q27. Genomic alteration was significantly more in patients less than 5-year survival than those with more than 5-year survival (P<0.05). CONCLUSION: Genomic instability can be an early event marker in carcinogenesis of nasopharyngeal carcinoma. Aggravation of genomic alterations is a poor prognosis for cancer recovery.

Inhibition of autophagy results in a reversal of taxol resistance in nasopharyngeal carcinoma by enhancing taxol-induced caspase-dependent apoptosis.

Drug resistance in nasopharyngeal carcinoma remains a major obstacle of clinical therapy. We found that the taxol-resistant cells demonstrated higher basal levels of autophagy than parental cells, which could be inhibited by 3-MA and Beclin-1-siRNA. We further revealed that inhibition of autophagy enhanced taxol-induced caspase-dependent apoptosis, resulted in partial reversal of the acquired taxol resistance in taxol-resistant cells. Our results suggest that the combination of an autophagy inhibitor with taxol may be a promising approach to promote therapeutic efficacy in patients with nasopharyngeal carcinoma.

Genomic instability in the progression of sporadic nasopharyngeal carcinoma.

OBJECTIVE: Genomic instability reflecting the susceptibility of the genome to acquire multiple genetic alterations plays a major role in tumorigenesis and tumor progression. We evaluated the prognostic significance of the extent of genomic instability in nasopharyngeal carcinoma. STUDY DESIGN AND SETTING: Genomic instability was assessed by inter-simple sequence repeats polymerase chain reaction (inter-SSR PCR) in 38 patients with nasopharyngeal carcinoma. Characterization and verification of band alterations shared in different tumors were carried out by sequencing and nest PCR. RESULTS: 31 (81.6%) of 38 patients showed genomic alterations, and genomic instability index ranged from 0 to 16.2%. A gain-based genomic damage shared in 6 tumors was identified on chromosome 6q27, a new mutator phenotype in nasopharyngeal carcinoma. Significantly more genomic alteration was found in patients without 5-year survival than that with 5-year survival (P<0.05), suggesting that higher genomic instability predicts a poor prognosis in nasopharyngeal carcinoma. CONCLUSIONS AND SIGNIFICANCE: Our data suggests that genomic instability can be an early event marker in carcinogenesis of nasopharyngeal carcinoma. Also, aggravation of genomic alterations is a poor prognosis for cancer recovery.

Endoscopic endonasal transsphenoidal approach for sellar tumors beyond the sellar turcica.

CONCLUSIONS: The endoscopic endonasal transsphenoidal approach can be a choice for sellar tumors beyond the sellar turcica, but it is necessary to make the choice carefully because of the severe surgical risks. OBJECTIVES: To summarize our experience of removal of sellar tumors beyond the sellar turcica via the endoscopic endonasal transsphenoidal approach and to evaluate the surgical efficacy and complications. METHODS: Between January 2007 and January 2012, 30 patients with sellar tumors beyond the sellar turcica underwent surgery using the endoscopic endonasal transsphenoidal approach. RESULTS: Postoperative pathological examination demonstrated that pituitary adenoma occurred in 22 patients, craniopharyngioma in 5, and meningioma in 3. Total removal was achieved in 21 patients (70.0%) and subtotal removal was achieved in 8 patients (26.7%). After the surgery, cerebrospinal fluid leakage occurred in 3 patients, temporary diabetes insipidus occurred in 25 patients and persistent diabetes insipidus in 4 patients, intracranial infection occurred in 1 patient, frontal subdural effusion occurred in 1 patient, sinusitis occurred in 2 patients, epistaxis occurred in 3 patients, and 1 patient with a huge pituitary adenoma died of hypothalamic failure related to the operation.

Efficacy of the modified endoscopic frontal sinus surgery for recurrent chronic frontal sinusitis.

To modify the endoscopic frontal sinus surgery and improve the therapeutic effect of recurrent chronic frontal sinusitis (RCFS). Eighty-five patients with RCFS were divided into two groups. Endoscopic frontal sinus surgery through an approach of Frontomaxillary Process-Agger Nasi, a modified Draf IIb procedure, was carried out in 51 patients (Group A), and conservative medication was applied in 34 patients as control (Group B). The therapeutic effect was prospectively evaluated with statistically validated measures of sinusitis-specific quality of life, sino-nasal outcome test-20 questionnaire (SNOT-20). Compared with pre-treatment, the average total score of SNOT-20 in RCFS patients was significantly decreased at the time of 6, 12 months after modified endoscopic frontal sinus surgery and medical treatments (p < 0.05). However, the total score of SNOT20 was significantly lower in group A than group B at the same period of the follow-up after treatments (p < 0.05). The overall efficacy evaluated by patients' self showed that the rate of "much improved" and "improved" was respectively 68.6 and 17.6 % in group A, and significantly better than group B (p < 0.001). Furthermore, the frontal sinus patency rate in group A was 85 %, and significantly higher than group B (p < 0.001). Endoscopic frontal sinus surgery through an approach of Frontomaxillary Process-Agger Nasi, a modified Draf IIb procedure, is an effective procedure to treat the RCFS.

[Nasopharyngeal teratomas (a case report and review of the literature)].

OBJECTIVE: To investigate the clinical characteristics of nasopharyngeal teratomas (NPT), improve the diagnosis and treatment of the disease. METHOD: We reported a 14 years old girl with NPT, and reviewed the literatures. RESULT: NPT was transorally expected under nasal endoscope, no recurrence was found over a 5 year follow-up. CONCLUSION: NPT is rare,the diagnosis of the disease relies on clinical manifestations, imaging and pathological examination. Transoral endoscopic surgery is an effective method of treatment.

Analysis of prognostic factors of endoscopic optic nerve decompression in traumatic blindness.

CONCLUSIONS: Hemorrhage within the ethmoid and/or sphenoid sinus and an interval between the time of injury and the time of operation exceeding 3 days are the risk factors for the visual prognosis of traumatic blindness. OBJECTIVES: To investigate the therapeutic efficacy of endoscopic optic nerve decompression in the treatment of traumatic blindness and to evaluate the relevant prognostic factors. METHODS: Eighty-five cases of traumatic blindness were analyzed retrospectively. Univariate analysis and multiple logistic regression were performed to evaluate potential prognostic factors. RESULTS: The overall rate of vision acuity improvement was 44.7% (38 of 85). Univariate analysis indicated that hemorrhage within the ethmoid and/or sphenoid sinus was significantly associated with unrecovered visual acuity. However, multiple logistic regression analysis identified that an interval between the time of injury and the time of operation exceeding 3 days, and hemorrhage within the ethmoid and/or sphenoid sinus were significantly correlated with the efficacy of treatment of traumatic blindness.

Long-term results of bilateral endoscopic vidian neurectomy in the management of moderate to severe persistent allergic rhinitis.

OBJECTIVE: To evaluate the long-term efficacy of bilateral endoscopic vidian neurectomy in the management of moderate to severe persistent allergic rhinitis. DESIGN: A prospective reassessment of the postoperative long-term results of bilateral endoscopic vidian neurectomy using the Rhinoconjunctivitis Quality of Life Questionnaire and visual analog scale for patients with moderate to severe persistent allergic rhinitis. SETTING: University hospital. PATIENTS: A total of 236 patients with moderate to severe persistent allergic rhinitis were divided into the following 3 treatment groups: those who underwent bilateral endoscopic vidian neurectomy (group 1, n = 93), those who underwent partial inferior turbinectomy and/or septoplasty (group 2, n = 51), and those who received conservative therapy (controls, n = 92). MAIN OUTCOME MEASURE: The patients' quality of life was assessed at 6 months, 1 year, and 3 years after undergoing the initial selected treatments for moderate to severe persistent allergic rhinitis. The complications were observed after treatment. RESULTS: Data from 199 of 236 patients who had complete follow-up documents were statistically analyzed. The average posttreatment bilateral endoscopic vidian neurectomy scores of the Rhinoconjunctivitis Quality of Life Questionnaire and visual analog scale were significantly improved at 6 months, 1 year, and 3 years compared with pretreatment scores for group 1 (P < .00) and for those in groups 2 and 3 during the same period. By the patient's self-evaluation posttreatment, the percentages of much improved, improved, and not improved was 64.7% (55 cases), 24.7% (21 cases), and 10.6% (9 cases), respectively. The percentages were significantly higher for those in group 1 than for those in group 2 (P < .05). No severe complication occurred in all 3 patient groups. CONCLUSION: In the hands of a well-trained surgeon bilateral endoscopic vidian neurectomy is an effective and safe technique in the management of moderate to severe persistent allergic rhinitis.

Inhibition of α folate receptor resulting in a reversal of taxol resistance in nasopharyngeal carcinoma.

OBJECTIVE: To further determine the role of FOLR1 in taxol resistance of nasopharyngeal carcinoma (NPC) and whether inhibition of FOLR1 expression reverses the taxol-resistant phenotype. STUDY DESIGN: Correlation study between gene expression and cancer cell survival. SETTING: University hospital. SUBJECTS AND METHODS: Three taxol-resistant sub-cell lines with a different resistant index were established from the parental CNE-1 NPC cell line. The correlation between FOLR1 expression and taxol sensitivity was statistically analyzed. Inhibition of FOLR1 expression was carried out by RNA interference and by a FOLR1-specific monoclonal antibody, and taxol sensitivity was examined by colony formation assays. FOLR1 expression was also examined in 72 NPC patient specimens by immunohistochemistry. RESULTS: The levels of FOLR1 expression were positively and significantly correlated with a taxol resistance phenotype (P < .05). Inhibition of FOLR1 expression resulted in a significantly increased sensitivity of taxol to taxol-resistant NPC cells (P < .05). An increase of FOLR1 expression by gene transfection caused a taxol-resistant phenotype in parental NPC cells. The level of FOLR1 expression was found to be related to clinical stage in NPC tissue samples. CONCLUSION: These results suggest that FOLR1 plays an important role in taxol resistance of NPC cells.