Deubiquitinating enzyme USP20 is a positive regulator of Claspin and suppresses the malignant characteristics of gastric cancer cells

The aim of the present study was to investigate the clinical significance, the biological function and the mechanisms of USP20 in gastric cancer. The expression of USP20 in 89 pairs of primary gastric cancer and peritumoral gastric tissues specimens were measured by immunohistochemistry. The correlation of USP20 expression with the survival and the clinicopathological characteristics of patients were analyzed. Moreover, the underlying mechanisms of ectopic USP20 expression and its impact on GC cells were also investigated. We found that the expression of USP20 is relatively low in GC tissues and negatively correlated with tumor size, tumor invasion and TNM staging. High expression of USP20 in GC predicted longer survival. Experimentally, small interfering RNA-mediated knockdown of USP20 expression significantly promoted cell proliferation, accelerated G1-S phase transition and attenuated the autophagy activity. Overexpression of USP20 led to the inhibition of proliferation, G1-S cell cycle transition delay and autophagy activation. Mechanistically, we confirmed that silencing the expression of USP20 in GC cells could reduce Claspin protein levels without altering Claspin mRNA levels, which is involved in the antitumor activity of USP20. Furthermore, the expression level of Claspin was relatively higher in peritumoral tissue than that of GC tissues and higher expression of Claspin in GC was also correlated with good prognosis of patients. Given its pivotal role in gastric tumorigenesis and progression, USP20 functioned as the tumor suppressor in GC and possessed promising value to be a therapeutic target for GC.

Augmented O-GlcNAc signaling via glucosamine attenuates oxidative stress and apoptosis following contrast-induced acute kidney injury in rats

Contrast-induced acute kidney injury (CI-AKI) is an iatrogenic renal injury and associated with substantial morbidity and mortality in susceptible individuals. Despite extensive study of a variety of agents for renal protection, limited strategies have been shown to be effective in the reduction of CI-AKI. O-linked β-N-acetylglucosamine (O-GlcNAc) is a post-translational regulatory modification of intracellular proteins and governs the function of numerous proteins, both cytosolic and nuclear. Increasing evidence suggests that O-GlcNAc levels are increased in response to stress and that acute augmentation of this reaction is cytoprotective. However, the underlying mechanisms by which augmented OGlcNAc signaling provides renoprotection against contrast media insults is still unknown. Here, we investigated the effect of augmented O-GlcNAc signaling via glucosamine on CI-AKI and explored the underlying molecular mechanisms, particularly its relationship with PI3-kinase (PI3K)/Akt signaling. We used a novel and reliable CI-AKI model consisting of 5/6 nephrectomized (NE) rats, and a low-osmolar contrast media (iohexol, 10mL/kg, 3.5gI) injected via the tail vein after dehydration for 48h. The results showed that augmented O-GlcNAc signaling by glucosamine prevented the kidneys against iohexol-induced injury characterized by the attenuation of renal dysfunction, tubular damage, apoptosis and oxidative stress. Furthermore, this renoprotection was blocked by treatment with alloxan, an O-GlcNAc transferase inhibitor. Augmented O-GlcNAc signaling also increased the protein expression levels of phospho-Akt (Ser473, but not Thr308 and Thr450), phospho-GSK-3β, Nrf2, and Bcl-2, and decreased the levels of Bax and cleaved caspase-3. Both alloxan and specific inhibitors of PI3K (Wortmannin and LY294002) blocked the protection of glucosamine via inhibiting Akt signaling pathway. We further identified O-GlcNAcylated Akt through immunoprecipitation and western blot. We confirmed that Akt was modified by O-GlcNAcylation, and glucosamine pretreatment increased the O-GlcNAcylation of Akt. Collectively, the results demonstrate that glucosamine induces renoprotection against CI-AKI through augmented O-GlcNAc and activation of PI3K/Akt signaling, making it a promising strategy for preventing CI-AKI.

Gastroprotective Effect of Alkaloids from Cortex Phellodendri on Gastric Ulcers in Rats through Neurohumoral Regulation

The present study aimed to investigate the gastroprotective activity of the total alkaloids from the bark of Phellodendron amurense and identify their possible mechanism. Total alkaloids were obtained through an alcohol extraction method and were analyzed using LC-MS/MS. Chronic gastric ulcers were induced by acetic acid (0.14 mol/L) filter paper on the gastric serosa. The antiulcer effect of total alkaloids was evaluated using the ulcer area, the ulcer inhibition ratio, and epidermal growth factor. The gastroprotective mechanism of total alkaloids was revealed using the levels of serotonin and noradrenaline. The results showed that oral administration of total alkaloids (30 mg/kg/day) obviously decreased the ulcer area (7.67 ± 2.06 mm²; p < 0.01) compared with the model group (15.15 ± 2.34 mm²). The ulcer inhibition ratio of the total alkaloids group (50 %) was higher than the omeprazole-treated group (46 %), which showed that the antiulcer effect of the total alkaloids may be superior to omeprazole. Besides, the total alkaloids significantly increased the epidermal growth factor level and accelerated the healing of ulcers. Histological examination of gastric tissues also supported the same conclusion. In addition, the total alkaloids significantly elevated the levels of serotonin and noradrenaline (both p < 0.01 compared to the model group). Our data indicates that total alkaloids of Cortex Phellodendri exerts a beneficial gastroprotective effect and the involved mechanism is likely neurohumoral regulation. Thus, Cortex Phellodendri may develop into a promising clinical medicinal agent for improving the quality of ulcer healing.

The path of mass transfer during Au thin film-assisted chemical etching by designed surface barriers

The mass transfer during the initial etching process: Si atoms dissolve in the Au film, and then diffuse across the Au lattice, and are oxidized and etched away at the Au film/solution interface.

TLR4 and Caveolin-1 in Monocytes Are Associated With Inflammatory Conditions in Diabetic Neuropathy

The purpose of this study was to investigate the expression of TLR4 and caveolin‐1 in monocytes among healthy volunteers as well as those with type‐2 diabetes mellitus (T2DM) and diabetic peripheral neuropathy (DPN). Nineteen healthy control subjects, 18 patients with T2DM, and 20 patients with DPN were enrolled. Toll‐like receptor (TLR)4, caveolin‐1, MyD88, phosphorylated IκB, and plasma TNF‐α and interleukin (IL)‐6 were measured using real‐time polymerase chain reaction, Western blotting, and enzyme‐linked immunosorbent assay. Compared with the other two groups, the DPN group had higher expression of TLR4, MyD88, phosphorylated IκB, TNF‐α, and IL‐6, but significantly lower levels of caveolin‐1 and total IκB in monocytes. Plasma concentrations of TNF‐α and IL‐6 were positively correlated with TLR4 and negatively correlated with caveolin‐1 in patients with DPN. Plasma concentration of TLR4 was negatively correlated with caveolin‐1 in patients with DPN. Reduced expression of caveolin‐1 in monocytes could aggravate the TLR4‐mediated inflammatory cascade.

The diagnostic value of serum fucosylated fetuin A in hepatitis B virus-related liver diseases

BACKGROUND

Some changes of glycoproteins have been identified in the serum of patients with different liver diseases, which provided potential glycan biomarkers for diagnosis, prognosis and monitoring of disease progression.

METHODS

We established a lectin-antibody sandwich ELISA method to detect fucosylated fetuin A (fuc-fetuin A) level in serum, in which biotinylated Aleuria aurantia lectin (AAL) was used for specific recognition. Then serum fuc-fetuin A level was detected in 108 healthy controls and 548 hepatitis B virus (HBV)-infected patients, including 232 hepatocellular carcinoma (HCC) patients, 114 liver cirrhosis (LC) patients, 86 liver fibrosis (LF) patients, and 116 asymptomatic HBV carriers, to assess its diagnostic and prognostic value in HBV-related liver diseases.

RESULTS

Serum fetuin A level decreased in LC patients as compared to HCC patients or healthy controls, while it decreased further according to the increasing Child-Pugh grades. The fuc-fetuin A level was in a decreasing order in LC, HCC, LF, HBV-carriers and healthy controls. For distinguishing LC and HCC patients from LF, HBV-carriers and healthy controls, the area under the receiver operating characteristic (ROC) curve is 0.871, with a sensitivity of 0.818 and specificity of 0.819. The survival analysis revealed that higher fuc-fetuin A level was significantly associated with worse recurrence-free survival in HCC patients (p=0.018).

CONCLUSIONS

The results indicated that the serum fuc-fetuin A might serve as a potential glycan biomarker for distinguishing LC and HCC from LF, HBV-carriers and healthy controls. Furthermore, the preoperative fuc-fetuin A level could be a useful prognostic biomarker for HCC patients.

Indoxyl Sulfate Enhance the Hypermethylation of Klotho and Promote the Process of Vascular Calcification in Chronic Kidney Disease

Chronic kidney disease (CKD) is a state of Klotho deficiency. The Klotho expression may be suppressed due to DNA hypermethylation in cancer cells so we have investigated the effects and possible mechanisms by which Klotho expression is regulated in human aortic smooth muscle cells (HASMCs). The vascular Klotho hypermethylation in radial arteries of patients with end-stage renal disease was described. Cultured HASMCs and 5/6-nephrectomized Sprague Dawley (SD) rats treated with indoxyl sulfate (IS) were used as in vitro and in vivo models, respectively. IS increased CpG hypermethylation of the Klotho gene and decreased Klotho expression in HASMCs, and potentiated HASMCs calcification. The expression of DNA methyltransferase (DNMT) 1 and 3a in HASMCs treated with IS was significantly increased and specific inhibition of DNA methyltransferase 1 by 5-aza-2'-deoxycytidine(5Aza-2dc) caused demethylation of the Klotho gene and increased Klotho expression. In rats, injection of IS potentiated vascular calcification, increased CpG hypermethylation of the Klotho gene and decreased Klotho expression in the aortic medial layer and all of these changes could be reverted by 5Aza-2dc treatment. Transcriptional suppression of vascular Klotho gene expression by IS and epigenetic modification of Klotho by IS may be an important pathological mechanism of vascular calcification in CKD.

[Efficacy of GLIDE chemotherapy for patients with newly diagnosed advanced-stage or relapsed/refractory extranodal natural killer cell lymphoma]

目的

研究GLIDE（吉西他滨、门冬酰胺酶、异环磷酰胺、地塞米松、依托泊苷）方案治疗初发进展期及复发难治性结外鼻型NK/T细胞淋巴瘤（ENKL）患者的有效性及安全性。

方法

纳入2010年3月至2016年3月收治的初发进展期及复发难治性ENKL患者42例，给予GLIDE方案化疗，中位疗程数为3(2~6）个，评估化疗结束后缓解率及早期（2个疗程后）缓解率，采用Kaplan-Meier方法统计无进展生存（PFS）及总生存（OS），同时采用Cox回归方法进行多因素分析，寻找影响患者PFS及OS的独立预后因素。

结果

31例（73.8%）患者达到完全缓解（CR），其中22例（52.4%）为早期CR，31例CR患者中14例接受序贯自体造血干细胞移植（ASCT）。1年PFS与OS率分别为65.6％和82.7%，4年PFS与OS率分别为48.2％和63.1%，中位OS时间未达到，中位PFS时间为30.5个月。多因素分析提示美国东部肿瘤协作组体能状态评分（ECOG评分）0~1分以及CR后序贯ASCT为减少复发、延长患者生存的有利因素。

结论

GLIDE方案能够有效治疗初发进展期及复发难治性ENKL, ECOG评分0~1分及CR后序贯ASCT治疗是患者获得较长PFS和OS时间的独立预后因素。

A Classification Tool for Differentiation of Kawasaki Disease from Other Febrile Illnesses

OBJECTIVE

To develop and validate a novel decision tree-based clinical algorithm to differentiate Kawasaki disease (KD) from other pediatric febrile illnesses that share common clinical characteristics.

STUDY DESIGN

Using clinical and laboratory data from 801 subjects with acute KD (533 for development, and 268 for validation) and 479 febrile control subjects (318 for development, and 161 for validation), we developed a stepwise KD diagnostic algorithm combining our previously developed linear discriminant analysis (LDA)-based model with a newly developed tree-based algorithm.

RESULTS

The primary model (LDA) stratified the 1280 subjects into febrile controls (n = 276), indeterminate (n = 247), and KD (n = 757) subgroups. The subsequent model (decision trees) further classified the indeterminate group into febrile controls (n = 103) and KD (n = 58) subgroups, leaving only 29 of 801 KD (3.6%) and 57 of 479 febrile control (11.9%) subjects indeterminate. The 2-step algorithm had a sensitivity of 96.0% and a specificity of 78.5%, and correctly classified all subjects with KD who later developed coronary artery aneurysms.

CONCLUSION

The addition of a decision tree step increased sensitivity and specificity in the classification of subject with KD and febrile controls over our previously described LDA model. A multicenter trial is needed to prospectively determine its utility as a point of care diagnostic test for KD.

Three-dimensional stress In vitro promotes the proliferation and differentiation of periodontal ligament stem cells implanted by bioactive glass

To analyze the biological and mechanical microenvironment on the directional differentiation of periodontal ligament stem cells (PDLSCs) In vitro. PDLSCs were cultured in three-dimensional stress system In vitro for 1, 2 and 3 weeks. Methods like immunohistochemistry and flow cytometry were adopted and the proliferation and differentiation situation of PDLSCs were determined. Bioactive glass (BAG) of 0%, 10%, 20%, 30% and 40% was implanted into PDLSCs with or without three-dimensional stress for 3 weeks, respectively. The proliferation and differentiation situation of PDLSCs were determined. The mRNA levels of Alkaline phosphatase (ALP), Type I Collagen (COL I), Type II Collagen (COL II), Bone sialoprotein (BSP), Osteocalcin (OCN) and Osteopontin (OPN) were determined by semi-quantitative RT-PCR. 30% BAG and three-dimensional stress for 3 weeks promoted the proliferation and differentiation of PDLSCs mostly. PDLSCs induced by BAG and 3D force and the control all expressed the mRNA of ALP, COLⅠand COL Ⅱ. The BAG and three-dimensional stress induced PDLSCs also expressed the mRNA of BSP, OCN and OPN. BAG and three-dimensional stress indicated microenvironment In vitro can promote the proliferation and differentiation of PDLSCs.

[Feasibility Study on Digital Signal Processor and Gear Pump of Uroflowmeter Calibration Device]

It will cause hidden trouble on clinical application if the uroflowmeter is out of control.This paper introduces a scheme of uroflowmeter calibration device based on digital signal processor(DSP)and gear pump and shows studies of its feasibility.According to the research plan,we analyzed its stability,repeatability and linearity by building a testing system and carried out experiments on it.The flow test system is composed of DSP,gear pump and other components.The test results showed that the system could produce a stable water flow with high precision of repeated measurement and different flow rate.The test system can calibrate the urine flow rate well within the range of 9~50mL/s which has clinical significance,and the flow error is less than 1%,which meets the technical requirements of the calibration apparatus.The research scheme of uroflowmeter calibration device on DSP and gear pump is feasible.

Identification of Natural Infections in Sheep/Goats with HoBi-like Pestiviruses in China

The natural infections of HoBi-like pestiviruses in cattle have been reported in South America, Europe and Asia. In China, although the detections of HoBi-like pestivirus have been reported, the epidemiological investigation was limited. From January 2014 to October 2015, several flocks of sheep/goats in Henan province in central China suffered respiratory diseases which were recovered slowly after antibiotics treatment. To test whether it is the HoBi-like pestivirus caused this symptom, 49 serum samples and 22 nasal swabs were then collected for analysis by serology and RT-PCR. Serological result revealed that prevalence of pestivirus in small ruminants was 12.2% (6/49) in central China. Sequence analysis of partial 5'-UTR nucleotides of pestivirus-positive samples suggested that HoBi-like pestivirus might have circulated in sheep/goats of China for a period and have evolved into new genotype clusters. It is apparent that the study provides the molecular evidence of natural infections in goat/sheep species with HoBi-like pestiviruses in China.

RNA sequencing reveals differentially expressed genes as potential diagnostic and prognostic indicators of gallbladder carcinoma

Gallbladder carcinoma (GBC) is a rare tumor with a dismal survival rate overall. Hence, there is an urgent need for exploring more specific and sensitive biomarkers for the diagnosis and treatment of GBC. At first, amplified total RNAs from two paired GBC tumors and adjacent non-tumorous tissues (ANTTs) were subjected to RNA sequencing. 161 genes were identified differentially expressed between tumors and ANTTs. Functional enrichment analysis indicated that the up-regulated genes in tumor were primarily associated with signaling molecules and enzyme modulators, and mainly involved in cell cycles and pathways in cancer. Twelve differentially expressed genes (DEGs) were further confirmed in another independent cohort of 35 GBC patients. Expression levels of BIRC5, TK1, TNNT1 and MMP9 were found to be positively related to postoperative relapse. There was also a significant correlation between BIRC5 expression and tumor-node-metastasis (TNM) stage. Besides, we observed a positive correlation between serum CA19-9 concentration and the expression levels of TNNT1, MMP9 and CLIC3. Survival analysis revealed that GBC patients with high TK1 and MMP9 expression levels had worse prognosis. These identified DEGs might not only be promising biomarkers for GBC diagnosis and prognosis, but also expedite the discovery of novel therapeutic strategies.

Xanthophyll supplementation reduced inflammatory mediators and apoptosis in hens and chicks

This study investigated effects of xanthophylls (containing 40% lutein and 60% zeaxanthin) on gene expression of inflammatory mediators ( [] and []) and apoptosis ( [] and ) of breeding hens and chicks. In Exp. 1, 432 hens were divided into 3 groups and fed diets supplemented with 0 (as the control group), 20, or 40 mg/kg xanthophylls. The liver, duodenum, jejunum, and ileum were sampled after 35 d. Results showed that 40 mg/kg of xanthophyll addition decreased in the liver, in the liver and duodenum, and in the liver and jejunum while increasing level in the liver and jejunum. Experiment 2 was a 2 × 2 factorial design. Male chicks hatched from hens fed 0 or 40 mg/kg xanthophyll diets were fed diets containing either 0 or 40 mg/kg xanthophylls. The liver, duodenum, jejunum, and ileum were sampled at 0, 7, 14, and 21 d after hatching. Results showed that in ovo xanthophylls reduced inflammatory mediators and apoptosis in the liver, duodenum, and jejunum of chicks mainly within 1 wk after hatching, whereas dietary xanthophylls only decreased expression in the liver from 2 wk onward. These results underlined important anti-inflammatory and antiapoptotic effects of maternal but not progeny dietary xanthophylls. In conclusion, xanthophylls can suppress inflammatory mediators and apoptosis in different tissues of hens and chicks.

[Effects of using different dose of dexmedetomidine during tracheal extubation for patients with parotidectomy after general anesthesia]

PURPOSE

To observe the effects of using different-dose dexmedetomidine during tracheal extubation for patients with parotidectomy after general anesthesia.

METHODS

Eighty patients with "ASA I-II"scheduled for parotidectomy under general anesthesia were randomly divided into 4 groups, dexmedetomidine group (D1, D2, D3 group) and control group (C group), 20 cases in each group. Anesthesia induction and maintenance were the same. Thirty minutes before the end of surgery, patients in group D1,D2,D3 and group C were infused dexmedetomidine 0.4, 0.8, 1.2 μg/kg diluted to 20 mL and the same volume of normal saline respectively within 10 minutes. After surgery, all patients were sent to the PACU. Extubation was applied to the patients who had extubation indications. SBP, DBP and HR were recorded at each time-point including T0(before induction), T1（the time when extubation, T2(5 min after extubation) and T3(10 min after extubation).The conditions of patients' bucking and agitation in PACU were also recorded. Other recorded indications included Ramsay scores and NRS at the time of extubation, extubation time and orientation recovery time. Statistical analysis was performed using SPSS20.0 software package.

RESULTS

SBP, DBP and HR at the time of extubation in group C, D1 increased significantly compared with those before extubation (P<0.05). SBP, DBP and HR in group D1 had no significant difference at T0, T1, T2 and T3 from those in group C (P>0.05). Ramsay scores and NRS in group D1 had no significant difference from those in group C (P>0.05). The incidence and degree of bucking in group D1 had declining tendency, but the difference was not significant (P>0.05). SBP, DBP and HR in group D2, D3 were significantly lower at each time-point than those in group C, D1 (P<0.05). The incidence and degree of bucking and agitation in group D2, D3 were lower and lighter than those in group C, D1 and Ramsay scores, NRS also had significant difference (P<0.05). Ramsay scores in group D3 were higher than those in group D2, and NRS in group D3 were significantly lower (P<0.05). Extubation time and orientation recovery time of group D3 were significantly longer than those in group D1, D2 and C (P<0.05).

CONCLUSIONS

Dexmedetomidine infusion before the end of parotidectomy can reduce hemodynamic fluctuation during the recovery period and improve the recovery quality. Moderate dose of dexmedetomidine (0.8 μg/kg) was more secure, and would not extend the extubation and orientation recovery time.

Abrp, a new gene, confers reduced susceptibility to tetracycline, glycylcine, chloramphenicol and fosfomycin classes in Acinetobacter baumannii

Acinetobacter baumannii, a non-fermenting gram-negative coccobacillus, is a major pathogen responsible for a variety of healthcare-associated infections, including pneumonia, urinary tract and bloodstream infections. Moreover, A. baumannii is associated with alarming increases in drug resistance rates to almost all available antibiotics leaving limited treatment options. Here, we characterize the biological functions of a novel gene, abrp, which encodes a peptidase C13 family. We demonstrate that the abrp is associated with decreased susceptibility to tetracycline, minocycline, doxycycline, tigecycline, chloramphenicol and fosfomycin. Deletion of abrp was able to increase cell membrane permeability and display slower cell growth rate. Results from the present study show that abrp plays an important role in conferring reduced susceptibility to different classes of antibiotics and cell growth in A. baumannii. The change of antibiotic sensitivities may result from modifications to the cell membrane permeability of A. baumannii.

Effect of cytokine-induced killer cells on immune function in patients with lung cancer

Cytokine-induced killer (CIK) cells have been used as adoptive immunotherapy in cancer. The present study evaluated the effect of CIK cells on immune function in patients with lung cancer. Patients were divided into three groups, according to the treatment received prior to CIK cell treatment: CIK group (no prior treatment), Che-Sur group (prior chemotherapy and surgery) and Che-Rad group (prior chemotherapy and radiotherapy). Following treatment, the average percentage of cluster of differentiation (CD)3⁺CD4⁺, CD3⁺, natural killer (NK) and NKT cells in peripheral blood was significantly higher than that prior to CIK treatment in the Che-Sur and CIK groups, and the levels of interferon-γ in serum were significantly higher than those prior to CIK treatment in the Che-Sur and CIK groups. On the contrary, the levels of interleukin-10 had decreased in these groups following CIK treatment. Subsequently, patients were divided into three groups according to the percentage of CD3⁺CD56⁺ CIK cells that were administered to the patients. The number of NK and NKT cells increased with increasing number of CD3⁺CD56⁺ cells. The patients in the CIK and Che-Sur groups were the most benefited ones following CIK treatment, contrarily to those in the Che-Rad group, since the increase in the number of CD3⁺CD56⁺ CIK cells in the aforementioned patients enhanced the number of NK cells, which exhibit antitumor activity.

Mitochondrial aldehyde dehydrogenase 2 protects gastric mucosa cells against DNA damage caused by oxidative stress

Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is a member of the aldehyde dehydrogenase superfamily and is involved with the metabolic processing of aldehydes. ALDH2 plays a cytoprotective role by removing aldehydes produced during normal metabolism. We examined the cytoprotective role of ALDH2 specifically in gastric mucosa cells. Overexpression of ALDH2 increased the viability of gastric mucosa cells treated with H2O2, while knockdown of ALDH2 had an opposite effect. Moreover, overexpression of ALDH2 protected gastric mucosa cells against oxidative stress-induced apoptosis as determined by flow cytometry, Hoechst 33342, and TUNEL assays. Consistently, ALDH2 knockdown had an opposite effect. Additionally, DNA damage was ameliorated in ALDH2-overexpressing gastric mucosa cells treated with H2O2. We further identified that this cytoprotective role of ALDH2 was mediated by metabolism of 4-hydroxynonenal (4-HNE). Consistently, 4-HNE mimicked the oxidative stress induced by H2O2 in gastric mucosa cells. Treatment with 4-HNE increased levels of DNA damage in ALDH2-knockdown GES-1 cells, while overexpression of ALDH2 decreased 4-HNE-induced DNA damage. These findings suggest that ALDH2 can protect gastric mucosa cells against DNA damage caused by oxidative stress by reducing levels of 4-HNE.

MiR-125a-5p decreases after long non-coding RNA HOTAIR knockdown to promote cancer cell apoptosis by releasing caspase 2

HOTAIR (homeobox transcript antisense RNA), one of the prototypical long non-coding RNAs, has been verified overexpressed in multiple carcinomas and has emerged as a promising novel anticancer target. Its well-established role is acting as a predictor of poor prognosis and promoting cancer cell metastasis. Recently, another important mission of HOTAIR was uncovered that targeting HOTAIR caused cancer cell apoptosis. Nevertheless, so far there is no published data elaborating the mechanism. Here, we report that microRNA miR-125a-5p decreases and releases caspase 2 to promote cancer cell apoptosis after HOTAIR knockdown. We applied siRNAs targeting HOTAIR to various cancer cells, and observed apoptosis in all of these cell lines. RNA sequencing detected that miR-125a-5p was decreased after HOTAIR knockdown and miR-125a-5p mimics could rescue the apoptosis induced by HOTAIR deficiency. Luciferase assays identified caspase 2, an initiator caspase, to be a new target of miR-125a-5p. Elevated expression and subsequent cleavage of caspase 2 was observed after HOTAIR knockdown or inhibition of miR-125a-5p. RNAi of caspase 2 could attenuate the apoptosis induced by HOTAIR knockdown. In 80 clinical colon cancer tissues, HOTAIR and miR-125a-5p levels were higher than adjacent tissues, whereas caspase 2 was lower. MiR-125a-5p expression level was significantly correlated with colon tumor size, lymph node metastasis and clinical stage. These findings indicate that miR-125a-5p decreases after HOTAIR knockdown to promote cancer cell apoptosis by releasing caspase 2. Our work reveals a previously unidentified apoptotic mechanism, which might be exploitable in anticancer drug development.