Clinical characteristics of tobacco smoke-induced versus biomass fuel-induced chronic obstructive pulmonary disease

Transition of cooking fuels and obesity risk in Chinese adults

BACKGROUND

Since 1990 s, China has witnessed a widespread transition to clean cooking fuels, presenting an opportunity to investigate whether household fuel transition could mitigate obesity risk and reconcile inconsistencies in the literature regarding the association between cooking fuels and obesity.

METHODS

The China Health and Nutrition Survey (CHNS) is a prospective cohort study covering 12 provinces of China (1989-2015). Participants were classified into persistent cleaner fuel users, fuel transitioners, and persistent polluting fuel users according to self-reported primary cooking fuels. Obesity and central obesity were defined as BMI ≥ 28.0 kg/m2 and waist circumference ≥ 90 cm in men and ≥ 85 cm in women according to Chinese criteria.

FINDINGS

Among 13,032 participants, 3657 (28.06 %) were persistent cleaner fuel users; 5264 (40.39 %) transitioned from using polluting fuels to cleaner fuels after the baseline survey; and 4111 (31.55 %) were persistent polluting fuel users. During the period of follow-up of 9.0 ± 6.8 years, 1248 (9.58 %) participants were classified into the obesity category, and 4703 (36.09 %) into the central obesity category. Persistent polluting fuel users had a significantly higher risk of developing obesity (hazard ratio [HR]: 1.45, 95 %CI: 1.22-1.72) and central obesity (HR: 1.32, 95 %CI: 1.21-1.44), compared to persistent cleaner fuel users. Persistent polluting fuel use was positively associated with developing obesity in women (HR: 1.64, 95 %CI: 1.30-2.06), but not in men. Subgroup analyses showed higher HR of persistent polluting fuel use among individuals aged 18-44 years (HR: 2.04, 95 %CI: 1.62-2.56). In contrast, the transitioners did not exhibit a significantly different risk of developing obesity (HR: 0.94, 95 %CI: 0.80-1.10) compared to persistent cleaner fuel users, which was consistent across different sex, age and urbanicity. Similar trends were observed for developing central obesity.

INTERPRETATION

Persistent polluting fuel use increased obesity risk while the obesity risk of the transition to cleaner fuels was similar to persistent use of cleaner fuels. The finding underscores the significance of advocating for the adoption of cleaner fuels as a strategy to mitigate the disease burden associated with obesity.

Investigating causal associations between pneumonia and lung cancer using a bidirectional mendelian randomization framework

BACKGROUND

Pneumonia and lung cancer are both major respiratory diseases, and observational studies have explored the association between their susceptibility. However, due to the presence of potential confounders and reverse causality, the comprehensive causal relationships between pneumonia and lung cancer require further exploration.

METHODS

Genome-wide association study (GWAS) summary-level data were obtained from the hitherto latest FinnGen database, COVID-19 Host Genetics Initiative resource, and International Lung Cancer Consortium. We implemented a bidirectional Mendelian randomization (MR) framework to evaluate the causal relationships between several specific types of pneumonia and lung cancer. The causal estimates were mainly calculated by inverse-variance weighted (IVW) approach. Additionally, sensitivity analyses were also conducted to validate the robustness of the causalty.

RESULTS

In the MR analyses, overall pneumonia demonstrated a suggestive but modest association with overall lung cancer risk (Odds ratio [OR]: 1.21, 95% confidence interval [CI]: 1.01 - 1.44, P = 0.037). The correlations between specific pneumonia types and overall lung cancer were not as significant, including bacterial pneumonia (OR: 1.07, 95% CI: 0.91 - 1.26, P = 0.386), viral pneumonia (OR: 1.00, 95% CI: 0.95 - 1.06, P = 0.891), asthma-related pneumonia (OR: 1.18, 95% CI: 0.92 - 1.52, P = 0.181), and COVID-19 (OR: 1.01, 95% CI: 0.78 - 1.30, P = 0.952). Reversely, with lung cancer as the exposure, we observed that overall lung cancer had statistically crucial associations with bacterial pneumonia (OR: 1.08, 95% CI: 1.03 - 1.13, P = 0.001) and viral pneumonia (OR: 1.09, 95% CI: 1.01 - 1.19, P = 0.037). Sensitivity analysis also confirmed the robustness of these findings.

CONCLUSION

This study has presented a systematic investigation into the causal relationships between pneumonia and lung cancer subtypes. Further prospective study is warranted to verify these findings.

[Epidemiology and hospitalization costs analysis of female inpatients with acute exacerbation of chronic obstructive pulmonary disease in Beijing from 2013 to 2020]

OBJECTIVE

To study epidemiological characteristics and hospitalization costs of female inpatients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in Beijing.

METHODS

A retrospective study was conducted to analyze electronic hospitalization summary reports of female inpatients with AECOPD in Beijing from 2013 to 2020. Clinical characteristics (age distribution and comorbidities), epidemiological characteristics (temporal and spatial distribution characteristics), hospi-talization times and costs of patients were described.

RESULTS

A total of 57 911 subjects in 166 hospitals were included in this study, with a mean age of (78.84±8.59) years and the highest number of patients aged 80-89 years (49.06%), followed by patients aged 70-79 years (31.08%), and the lowest number of patients under 50 years (0.41%). The proportions of patients with coronary heart disease, hypertension and heart failure were 30.60%, 30.52% and 26.54% respectively. The median number of daily hospitalizations during the study period was 18 (IQR: 16). The number of daily hospitalizations for AECOPD showed an overall growth trend over the eight years from 2013 to 2020, starting to increase significantly in 2015 and continuing to increase until 2019, then followed by a decline in 2020. The proportion of inpatient admissions was higher in winter and spring (54.09%) than that in summer and autumn (45.91%). The top three districts in terms of the proportion of total inpatient admissions were Xicheng district (14.18%), Chaoyang district (14.12%) and Fengtai district (13.47%). The density of inpatients was relatively high in the western regions, central urban areas and northeastern regions of the city, while the density of inpatients was relatively low in the near suburbs. The median number of hospital days for female patients with AECOPD was 12 days, and the median hospital costs was CNY 20 648.37. Patients from urban areas had longer hospitalization times and higher hospitalization costs than those from suburban areas (P < 0.001). Western medicine expenses accounted for the largest proportion of total hospital expenses (33.32%). During the study period, hospitalization costs exhibited an overall pattern of initial growth, followed by subsequent decline, eventually stabilizing. The differences in hospitalization costs among the patients with different comorbidities were significant.

CONCLUSION

Female hospitalized patients with AECOPD in Beijing were older than 70 years, often complicated by cardiovascular disease. AECOPD occurred mainly in winter and spring, with regional differences. The hospitalization costs were closely associated with the patients' age, comorbidities, and the geographicical region.

Analyses of Factors Associated with Acute Exacerbations of Chronic Obstructive Pulmonary Disease: A Review

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is the exacerbation of a range of respiratory symptoms during the stable phase of chronic obstructive pulmonary disease (COPD). AECOPD is thus a dangerous stage and key event in the course of COPD, as its deterioration and frequency seriously affects the quality of life of patients and shortens their survival. Acute exacerbations occur and develop due to many factors such as infection, tobacco smoke inhalation, air pollution, comorbidities, airflow limitation, various biomarkers, history of previous deterioration, natural killer cell abnormalities, immunoglobulin G deficiency, genetics, abnormal muscle and nutritional status, negative psychology, and seasonal temperature changes. There is relatively limited research on the impact of the role of standardized management on the alleviation of AECOPD. However, with the establishment of relevant prevention and management systems and the promotion of artificial intelligence technology and Internet medical approaches, long-term effective and standardized management of COPD patients may help to achieve the quality of life and disease prognosis in COPD patients and reduce the risk of AE.

A Risk-Scoring Model for Severe Checkpoint Inhibitor-Related Pneumonitis: A Case-Control Study

BACKGROUND AND OBJECTIVE

Checkpoint inhibitor-related pneumonitis (CIP) is one of the most common serious and fatal adverse events associated with immune checkpoint inhibitors (ICIs). The study sought to identify risk factors of all-grade and severe CIP and to construct a risk-scoring model specifically for severe CIP.

METHODS

This observational, retrospective case-control study involved 666 lung cancer patients who received ICIs between April 2018 and March 2021. The study analyzed patient demographic, preexisting lung diseases, and the characteristics and treatment of lung cancer to determine the risk factors for all-grade and severe CIP. A risk score for severe CIP was developed and validated in a separate patient cohort of 187 patients.

RESULTS

Among 666 patients, 95 patients were afflicted with CIP, of which 37 were severe cases. Multivariate analysis revealed age ≥ 65 years, current smoking, chronic obstructive pulmonary disease, squamous cell carcinoma, prior thoracic radiotherapy, and extra-thoracic radiotherapy during ICI were independently associated with CIP events. Five factors, emphysema (odds ratio [OR] 2.87), interstitial lung disease (OR 4.76), pleural effusion (OR 3.00), history of radiotherapy during ICI (OR 4.30), and single-agent immunotherapy (OR 2.44) were independently associated with severe CIP and were incorporated into a risk-score model (score ranging 0-17). The area under the model receiver operating characteristic curve for the model was 0.769 in the development cohort and 0.749 in the validation cohort.

CONCLUSIONS

The simple risk-scoring model may predict severe CIP in lung cancer patients receiving ICIs. For patients with high scores, clinicians should use ICIs with caution or strengthen the monitoring of these patients.

Machine learning reveals sex differences in clinical features of acute exacerbation of chronic obstructive pulmonary disease: A multicenter cross-sectional study

Introduction

Intrinsically, chronic obstructive pulmonary disease (COPD) is a highly heterogonous disease. Several sex differences in COPD, such as risk factors and prevalence, were identified. However, sex differences in clinical features of acute exacerbation chronic obstructive pulmonary disease (AECOPD) were not well explored. Machine learning showed a promising role in medical practice, including diagnosis prediction and classification. Then, sex differences in clinical manifestations of AECOPD were explored by machine learning approaches in this study.

Methods

In this cross-sectional study, 278 male patients and 81 female patients hospitalized with AECOPD were included. Baseline characteristics, clinical symptoms, and laboratory parameters were analyzed. The K-prototype algorithm was used to explore the degree of sex differences. Binary logistic regression, random forest, and XGBoost models were performed to identify sex-associated clinical manifestations in AECOPD. Nomogram and its associated curves were established to visualize and validate binary logistic regression.

Results

The predictive accuracy of sex was 83.930% using the k-prototype algorithm. Binary logistic regression revealed that eight variables were independently associated with sex in AECOPD, which was visualized by using a nomogram. The AUC of the ROC curve was 0.945. The DCA curve showed that the nomogram had more clinical benefits, with thresholds from 0.02 to 0.99. The top 15 sex-associated important variables were identified by random forest and XGBoost, respectively. Subsequently, seven clinical features, including smoking, biomass fuel exposure, GOLD stages, PaO2, serum potassium, serum calcium, and blood urea nitrogen (BUN), were concurrently identified by three models. However, CAD was not identified by machine learning models.

Conclusions

Overall, our results support that the clinical features differ markedly by sex in AECOPD. Male patients presented worse lung function and oxygenation, less biomass fuel exposure, more smoking, renal dysfunction, and hyperkalemia than female patients with AECOPD. Furthermore, our results also suggest that machine learning is a promising and powerful tool in clinical decision-making.

Clinical-functional characteristics and risk of exacerbation and mortality among more symptomatic patients with chronic obstructive pulmonary disease: a retrospective cohort study

OBJECTIVES

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 classified chronic obstructive pulmonary disease (COPD) patients into more and less symptomatic groups. This study aimed to analyze the clinical characteristics, risk of future exacerbation and mortality among patients in more symptomatic group.

DESIGN

A retrospective cohort study.

SETTING

Data were obtained from patients enrolled in a database setup by Second Xiangya Hospital of Central South University.

PARTICIPANTS

1729 stable COPD patients listed from September 2017 to December 2019 in the database. The patients were classified into more and less symptomatic groups based on GOLD 2017 report.

OUTCOMES

All patients were followed up for 18 months. We collected baseline data and recorded the number of exacerbations and mortality during follow-up.

RESULTS

The more symptomatic patients were older, had higher Clinical COPD Questionnaire (CCQ) scores, more severe airflow limitation and higher number of exacerbations and hospitalizations in the past year (P < 0.05). Logistic regression showed that having more symptoms correlated with the CCQ scores and exacerbations in the past year (P < 0.05). After patients were followed up, there were higher numbers of exacerbations, hospitalizations and mortality rates in more symptomatic patients (P < 0.05). The multivariate model showed that age more than 65 years (OR = 2.047, 95% CI = 1.020-4.107) and COPD assessment test scores more than 30 (OR = 2.609, 95% CI = 1.339-5.085) were independent risk factors for mortality, whereas current smoker (OR = 1.565, 95% CI = 1.052-2.328), modified Medical Research Council scores (OR = 1.274, 95% CI = 1.073-1.512) and exacerbations in the past year (OR = 1.061, 95% CI = 1.013-1.112) were independent risk factors for exacerbation in more symptomatic patients (P < 0.05).

CONCLUSIONS

More symptomatic COPD patients have worse outcomes. In addition, several independent risk factors for exacerbation and mortality were identified. Therefore, clinicians should be aware of these risk factors and take them into account during interventions.

The "Slow Horse Racing Effect" on Lung Function in Adult Life in Chronic Obstructive Pulmonary Disease Associated to Biomass Exposure

Although different trajectories in lung function decline have been identified in patients with COPD associated to tobacco exposure (TE-COPD), genetic, environmental, and infectious factors affecting lung function throughout life have not been fully elucidated in patients with COPD associated to biomass (BE-COPD). In this review, we present current epidemiological findings and notable advances in the natural history of lung decline in BE-COPD, as well as conditions modeling the FEV₁ trajectory, such as health insults, during the first years of childhood. Evidence shows that women exposed to biomass smoke reach adult life with a lower FEV₁ than expected. However, in contrast to the “horse racing effect” predicting an excessive lung-function decline in forthcoming years, as observed in smokers, this decline is slower in non-smokers, and no rapid decliners are observed. Accordingly, BE-COPD might be considered another phenotype of COPD based on assessments of lung function decline. Likewise, other functional and clinical aspects described in this review suggest that this condition might be similar to TE-COPD. More research is needed to fully characterize this subgroup of variants of COPD.

Independent and combined associations of solid-fuel use and smoking with obesity among rural Chinese adults

Although solid-fuel use or smoking is associated with obesity measured by body mass index (BMI), research on their interactive effects on general and central obesity is limited. Data of 20,140 individuals in the Henan Rural Cohort Study was examined the independent and combined associations of solid-fuel use and smoking with prevalent obesity, which was measured by BMI, waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), body fat percentage (BFP), and visceral fat index (VFI). Multiple adjusted logistic regression models showed that the OR (95% CI) of prevalent obesity measured by BMI associated with exposure to solid fuels alone or with smoking was 0.78 (0.70, 0.86) or 0.46 (0.32, 0.66), compared with neither smoking nor solid-fuel exposure. Similar results had been found in other obese anthropometric indices and in the results of linear regression analysis. The results indicated that solid-fuel use and smoking have a synergistic effect on reduction in obesity indices. The effects of household air pollution from solid-fuel use and smoking on obesity should be considered when exploring the influencing factors of obesity.

Disruptions in oral and nasal microbiota in biomass and tobacco smoke associated chronic obstructive pulmonary disease

Chronic exposures to tobacco and biomass smoke are the most prevalent risk factors for COPD development. Although microbial diversity in tobacco smoke-associated COPD (TSCOPD) has been investigated, microbiota in biomass smoke-associated COPD (BMSCOPD) is still unexplored. We aimed to compare the nasal and oral microbiota between healthy, TSCOPD, and BMSCOPD subjects from a rural population in India. Nasal swabs and oral washings were collected from healthy (n = 10), TSCOPD (n = 11), and BMSCOPD (n = 10) subjects. The downstream analysis was performed using QIIME pipeline (v1.9). In nasal and oral microbiota no overall differences were noted, but there were key taxa that had differential abundance in either Healthy vs COPD and/or TSCOPD vs. BMSCOPD. Genera such as Actinomyces, Actinobacillus, Megasphaera, Selenomonas, and Corynebacterium were significantly higher in COPD subjects. This study suggests that microbial community undergoes dysbiosis which may further contribute to the progression of disease. Thus, it is important to identify etiological agents for such a polymicrobial alterations which contribute highly to the disease manifestation.

Association of biomass fuel use with reduced body weight of adult Ghanaian women

The association of biomass fuel use with body weight has never been investigated. We therefore examined the effect of biomass fuel use on body weight of adult Ghanaian women. Data from the 2014 Ghana Demographic and Health Survey, a nationally representative population-based survey was analysed for this study. A total of 4751 women who had anthropometric (height and weight) data qualified for inclusion in this study. In linear regression modelling, charcoal use resulted in 3.08 kg (95% CI: 2.04, 4.12) and 0.81 kg/m² (95%CI: 0.29, 1.33) reduction in weight and body mass index (BMI), respectively, compared to clean fuel (electricity, liquefied petroleum gas and natural gas) use. Use of wood resulted in much higher reduction in weight and BMI. In modified Poisson regression, charcoal users had 19% (Adjusted Prevalence Ratio [aPR] = 0.81; 95%CI: 0.71, 0.92) and 29% (aPR = 0.71; 95%CI: 0.61, 0.83) decreased risk of overweight and obesity, respectively, compared to clean fuel users. Wood users had much higher decreased risk of overweight and obesity. In conclusion, biomass fuel use was associated with reduced body weight and BMI of Ghanaian women and is the first report on the relationship. However, it is important that our findings are confirmed and the biological mechanisms elucidated through rigorous study designs.

Small cell lung cancer starting with diabetes mellitus: Two case reports and literature review

BACKGROUND

Small-cell lung cancer (SCLC) is a type of fatal tumor that is increasing in prevalence. While these are unpleasant facts to consider, it is vitally important to be informed, and it is important to catch the disease early. Typically, lung cancer does not show severe clinical symptoms in the early stage. Once lung cancer has progressed, patients might present with classical symptoms of respiratory system dysfunction. Thus, the prognosis of SCLC is closely related to the early diagnosis of the disease. Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is related to cancer occurrence, especially for SCLC with the presence of Cushing's syndrome, which is dependent on markedly elevated ACTH and cortisol levels.

CASE SUMMARY

In the current report, we describe two middle-age patients who were originally diagnosed with diabetes mellitus with no classical symptoms of lung cancer. The patients were eventually diagnosed with SCLC, which was confirmed by bronchoscopic biopsy and histopathology. SCLC-associated diabetes was related to EAS, which was an endogenous ACTH-dependent form of Cushing’s syndrome with elevated ACTH and cortisol levels. Multiple organ metastases were found in Patient 1, while Patient 2 retained good health at 2 years follow-up. EAS symptoms including thyroid dysfunction, hypercortisolism and glucose intolerance were all resolved after anticancer treatment.

CONCLUSION

In conclusion, SCLC might start with diabetes mellitus and increased cortisol and hypokalemia or other EAS symptoms. These complex clinical features were the most significant factors to deteriorate a patient’s condition. Early diagnosis and treatment from clinicians were essential for the anti-cancer treatment for patients with SCLC.

Umeclidinium bromide versus placebo for people with chronic obstructive pulmonary disease (COPD)

BACKGROUND

People with chronic obstructive pulmonary disease (COPD) have poor quality of life, reduced survival, and accelerated decline in lung function, especially associated with acute exacerbations, leading to high healthcare costs. Long-acting bronchodilators are the mainstay of treatment for symptomatic improvement, and umeclidinium is one of the new long-acting muscarinic antagonists approved for treatment of patients with stable COPD.

OBJECTIVES

To assess the efficacy and safety of umeclidinium bromide versus placebo for people with stable COPD.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov, the World Health Organization (WHO) trials portal, and the GlaxoSmithKline (GSK) Clinical Study Register, using prespecified terms, as well as the reference lists of all identified studies. Searches are current to April 2017.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of parallel design comparing umeclidinium bromide versus placebo in people with COPD, for at least 12 weeks.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. If we noted significant heterogeneity in the meta-analyses, we subgrouped studies by umeclidinium dose.

MAIN RESULTS

We included four studies of 12 to 52 weeks' duration, involving 3798 participants with COPD. Mean age of participants ranged from 60.1 to 64.6 years; most were males with baseline mean smoking pack-years of 39.2 to 52.3. They had moderate to severe COPD and baseline mean post-bronchodilator forced expiratory volume in one second (FEV₁) ranging from 44.5% to 55.1% of predicted normal. As all studies were systematically conducted according to prespecified protocols, we assessed risk of selection, performance, detection, attrition, and reporting biases as low.Compared with those given placebo, participants in the umeclidinium group had a lesser likelihood of developing moderate exacerbations requiring a short course of steroids, antibiotics, or both (odds ratio (OR) 0.61, 95% confidence interval (CI) 0.46 to 0.80; four studies, N = 1922; GRADE: high), but not specifically requiring hospitalisations due to severe exacerbations (OR 0.86, 95% CI 0.25 to 2.92; four studies, N = 1922, GRADE: low). The number needed to treat for an additional beneficial outcome (NNTB) to prevent an acute exacerbation requiring steroids, antibiotics, or both was 18 (95% CI 13 to 37). Quality of life was better in the umeclidinium group (mean difference (MD) -4.79, 95% CI -8.84 to -0.75; three studies, N = 1119), and these participants had a significantly higher chance of achieving a minimal clinically important difference of at least four units in St George's Respiratory Questionnaire (SGRQ) total score compared with those in the placebo group (OR 1.45, 95% CI 1.16 to 1.82; three studies, N = 1397; GRADE: moderate). The NNTB to achieve one person with a clinically meaningful improvement was 11 (95% CI 7 to 29). The likelihood of all-cause mortality, non-fatal serious adverse events (OR 1.33; 95% CI 0.89 to 2.00; four studies, N = 1922, GRADE: moderate), and adverse events (OR 1.06, 95% CI 0.85 to 1.31; four studies, N = 1922; GRADE: moderate) did not differ between umeclidinium and placebo groups. The umeclidinium group demonstrated significantly greater improvement in change from baseline in trough FEV₁ compared with the placebo group (MD 0.14, 95% CI 0.12 to 0.17; four studies, N = 1381; GRADE: high). Symptomatic improvement was more likely in the umeclidinium group than in the placebo group, as determined by Transitional Dyspnoea Index (TDI) focal score (MD 0.76, 95% CI 0.43 to 1.09; three studies, N = 1193), and the chance of achieving a minimal clinically important difference of at least one unit improvement was significantly higher with umeclidinium than with placebo (OR 1.71, 95% CI 1.37 to 2.15; three studies, N = 1141; GRADE: high). The NNTB to attain one person with clinically important symptomatic improvement was 8 (95% CI 5 to 14). The likelihood of rescue medication usage (change from baseline in the number of puffs per day) was significantly less for the umeclidinium group than for the placebo group (MD -0.45, 95% CI -0.76 to -0.14; four studies, N = 1531).

AUTHORS' CONCLUSIONS

Umeclidinium reduced acute exacerbations requiring steroids, antibiotics, or both, although no evidence suggests that it decreased the risk of hospital admission due to exacerbations. Moreover, umeclidinium demonstrated significant improvement in quality of life, lung function, and symptoms, along with lesser use of rescue medications. Studies reported no differences in adverse events, non-fatal serious adverse events, or mortality between umeclidinium and placebo groups; however, larger studies would yield a more precise estimate for these outcomes.

Elevated HOTAIR expression associated with cisplatin resistance in non-small cell lung cancer patients

BACKGROUND

This study investigated the mechanism of drug resistance in non-small cell lung cancer (NSCLC) patients. We specifically studied whether long noncoding RNAs influence drug resistance in NSCLC to discover new therapeutic targets to increase the survival rate of drug-resistant NSCLC patients.

METHODS

Tissue samples were collected from NSCLC patients, and total RNA was isolated for assessment of HOTAIR expression and drug resistance status. MTT assays, tumor sphere formation assays, and western blot were performed to cytologically determine the relationship between HOTAIR expression and cisplatin resistance, as well as to elucidate the potential molecular mechanism involved.

RESULTS

HOTAIR expression in tissues of drug-resistant NSCLC patients was higher than that of non-drug-resistant patients. HOTAIR expression was elevated in cisplatin-resistant cell strains (A549/CDDP), and reducing HOTAIR expression increased the sensitivity of A549/CDDP cells to cisplatin. In addition, overexpression of HOTAIR in A549 cells increased resistance to cisplatin. Tumor sphere formation assays showed that the volume of spheres formed by cell strains expressing elevated levels of HOTAIR was greater than that of cell strains with low expression. Western blot experiments showed that elevated expression of HOTAIR upregulated tumor stem cell-related biomarkers and HOTAIR expression was directly related to Klf4 expression.

CONCLUSIONS

Elevated HOTAIR expression is associated with drug resistance in NSCLC patients and is related to Klf4 upregulation, providing a new therapeutic target for drug-resistant NSCLC patients.