Thiol oxidative stress-dependent degradation of transglutaminase2 via protein S-glutathionylation sensitizes 5-fluorouracil therapy in 5-fluorouracil-resistant colorectal cancer cells.

5-Fluorouracil (5-Fu) is a first-line drug for colorectal cancer (CRC) therapy. However, the development of 5-Fu resistance limits its chemotherapeutic effectiveness and often leads to poor prognoses of CRC. Transglutaminase 2 (TGM2), a member of the transglutaminase family, is considered to be associated with chemoresistance through apoptotic prevention in various cancers including CRC. TGM2 was found to be overexpressed in two 5-Fu-resistant CRC cell lines and down-regulated by increased thiol oxidative stress induced by inhibition of glutathione reductase (GR). The present study aimed to explore the role of TGM2 in 5-Fu-resistant CRC and the mechanism of action by which the elevated thiol oxidative stress down-regulates TGM2 protein level. The results revealed that 5-Fu-resistance induced by overexpression of TGM2 in CRC cells was reversed through up-regulation of thiol oxidative stress. Knockdown of TGM2 increased the chemosensitivity of CRC cells to 5-Fu. Thiol oxidative stress potentially enhanced the therapeutic effect of 5-Fu in the resistant CRC cells by promotion of 5-Fu-induced apoptosis through down-regulation of TGM2. The elevated thiol oxidative stress increased the S-glutathionylation of TGM2 and led to proteasomal degradation of TGM2. Furthermore, Cys193 was identified as the S-glutathionylation site in TGM2, and its mutation resulted in thiol oxidative stress-mediated CRC cell apoptotic resistance. TGM2-induced EMT was also suppressed by the elevated thiol oxidative stress. A xenograft tumor model confirmed the effect of thiol oxidative stress in the reversal of 5-Fu resistance in CRC cells in vivo. TGM2 protein expression level was found to be significantly higher in human CRC specimens than in non-cancerous colorectal tissues. Taken together, the present data suggest an important role of TGM2 in 5-Fu resistance in CRC cells. Up-regulation of thiol oxidative stress could be a potential therapeutic approach for treating 5-Fu-resistant CRC and TGM2 may serve as a potential therapeutic target of thiol oxidative stress.

Clinical and prognostic significance of perioperative change in red cell distribution width in patients with esophageal squamous cell carcinoma.

BACKGROUND: Numerous studies have reported the prognostic significance of the red cell distribution width (RDW) in patients with esophageal squamous cell carcinoma (ESCC), but the relationship between the perioperative change in RDW (delta RDW) and survival in patients with ESCC after surgery has not been evaluated. METHODS: A total of 594 patients with newly diagnosed ESCC after surgery were enrolled in the study. Delta RDW (delta RDW = Postoperative RDW-Preoperative RDW) was counted based on data within one week before surgery and two weeks after surgery. To investigate the relationship between delta RDW and overall survival (OS), the median delta RDW was chosen as the cut-off value. RESULTS: 99 (16.7%) patients had pathological stage 1a-1b, 202 (34.0%) patients had pathological stage 2a-2b, and 293 (49.3%) patients had pathological stage 3a-3c.There were 179 (30.1%) patients who had vessel invasive, and 415 (69.9%) patients without vessel invasive. There were 216 (36.4%) patients with nerve infiltration, and 378 (63.6%) without nerve infiltration. In univariate analysis, five parameters including delta RDW(≥ 0.44 vs.<0.44) (P = 0.039, HR = 1.337, 95% CI = 1.014-1.762) significantly correlated with worse OS. Multivariate analysis revealed that delta RDW(≥ 0.44 vs.<0.44) was an independent prognostic marker for OS (P = 0.033, HR = 1.356, 95% CI = 1.025-1.793). Kaplan-Meier curves showed that delta RDW ≥ 0.44 was significantly associated with worse OS (P = 0.039). Subgroup analysis suggested that delta RDW ≥ 0.44 indicated worse survival in patients with ESCC exclusively in these subtypes such as female patients, age > 60 patients, patients with lymph node metastasis, and patients with vessel invasive. CONCLUSIONS: Perioperative change in red cell distribution width predicts worse survival in patients with ESCC after surgery.

Development of a serum miRNA panel for detection of early stage non-small cell lung cancer.

Minimally invasive testing for early detection of lung cancer to improve patient survival is a major unmet clinical need. This study aimed to develop and validate a serum multi-microRNA (multimiR) panel as a minimally invasive test for early detection of nonsmall cell lung cancer (NSCLC) regardless of smoking status, gender, and ethnicity. Our study included 744 NSCLC cases and 944 matched controls, including smokers and nonsmokers, male and female, with Asian and Caucasian subjects. Using RT-qPCR and a tightly controlled workflow, we quantified the absolute expression of 520 circulating microRNAs (miRNAs) in a Chinese cohort of 180 early stage NSCLC cases and 216 healthy controls (male smokers). Candidate biomarkers were verified in two case-control cohorts of 432 Chinese and 218 Caucasians, respectively (including females and nonsmokers). A multimiR panel for NSCLC detection was developed using a twofold cross-validation and validated in three additional Asian cohorts comprising 642 subjects. We discovered 35 candidate miRNA biomarkers, verified 22 of them, and developed a five-miR panel that detected NSCLC with area under curve (AUC) of 0.936-0.984 in the discovery and verification cohorts. The panel was validated in three independent cohorts with AUCs of 0.973, 0.916, and 0.917. The sensitivity of five-miR test was 81.3% for all stages, 82.9% for stages I and II, and 83.0% for stage I NSCLC, when the specificity is at 90.7%. We developed a minimally invasive five-miR serum test for detecting early stage NSCLC and validated its performance in multiple patient cohorts independent of smoking status, gender, and ethnicity.

Multimodal Sonographic Appearance and Survival Outcomes of 69 Cases of Primary Thyroid Lymphoma Over 10 Years.

OBJECTIVES: To investigate ultrasound appearance and the survival outcomes for patients with primary thyroid lymphoma (PTL). METHODS: Ultrasonic images and clinical characteristics from pathologically confirmed 69 PTL patients (2008-2019) were retrospectively analyzed. The clinical characteristics, ultrasonic characters, and prognostic factors were analyzed. Survival curves were plotted using the Kaplan-Meier method. Univariate and multivariate analyses were performed. RESULTS: Of the 69 study patients, 23 were indolent PTL and 46 were aggressive PTL. Age (>70 years old) and elevated lactate dehydrogenase levels were statistically different clinical features between aggressive and indolent PTL. From ultrasonic images, 34 cases were nodular, 11 diffuse, and 24 mixed pattern. Mixed types displayed high invasiveness (45.7%) while diffuse types displayed higher inertness (39.1%), with statistically significant differences (P = .000). Invaded thyroid capsule and increased chaotic vascularity also showed significant differences between aggressive and indolent PTL. We also observed statistical difference in overall survival rates between aggressive and indolent PTL (P = .032). Single factor K-M analyses showed that age >70 years, aggressive pathology, and Ki67 >30% were positively correlated with the risk of poor PTL survival (P < .05). CONCLUSIONS: Multimodal ultrasound provides accurate ultrasonographic information and facilitates PTL invasiveness diagnostics for improved clinical treatment. In addition, PTL patients aged >70 years, with aggressive pathology, and Ki67 >30% were more likely to have a poor survival outcome.

Perioperative change in neutrophil count predicts worse survival in esophageal squamous cell carcinoma.

Aims: This study aimed to investigate the relationship between perioperative change in neutrophil count and survival of patients with esophageal squamous cell carcinoma. Method: Neutrophil change (Nc) (where Nc = post-surgery neutrophil count - pre-surgery neutrophil count) was counted according to data within 1 week before surgery and 2 weeks after surgery. Patients were divided into two groups, Nc ≥2.60 and Nc <2.60, according to the median of Nc. Results: Multivariate analysis revealed that Nc ≥2.60 was an independent prognostic marker for overall survival. Subgroup analysis suggested that the overall survival of male patients, patients aged ≤60 years, patients without vessel invasion and patients without nerve infiltration was dramatically worse for those with Nc <2.60. Conclusion: Perioperative change in neutrophil count predicts worse survival in esophageal squamous cell carcinoma after surgery.

Next-generation DNA damage sequencing.

Cellular DNA is constantly chemically altered by exogenous and endogenous agents. As all processes of life depend on the transmission of the genetic information, multiple biological processes exist to ensure genome integrity. Chemically damaged DNA has been linked to cancer and aging, therefore it is of great interest to map DNA damage formation and repair to elucidate the distribution of damage on a genome-wide scale. While the low abundance and inability to enzymatically amplify DNA damage are obstacles to genome-wide sequencing, new developments in the last few years have enabled high-resolution mapping of damaged bases. Recently, a number of DNA damage sequencing library construction strategies coupled to new data analysis pipelines allowed the mapping of specific DNA damage formation and repair at high and single nucleotide resolution. Strikingly, these advancements revealed that the distribution of DNA damage is heavily influenced by chromatin states and the binding of transcription factors. In the last seven years, these novel approaches have revealed new genomic maps of DNA damage distribution in a variety of organisms as generated by diverse chemical and physical DNA insults; oxidative stress, chemotherapeutic drugs, environmental pollutants, and sun exposure. Preferred sequences for damage formation and repair have been elucidated, thus making it possible to identify persistent weak spots in the genome as locations predicted to be vulnerable for mutation. As such, sequencing DNA damage will have an immense impact on our ability to elucidate mechanisms of disease initiation, and to evaluate and predict the efficacy of chemotherapeutic drugs.

Impact of DNA Oxidation on Toxicology: From Quantification to Genomics.

Understanding the toxicological implications of deoxyribonucleic acid (DNA) oxidation arising from cellular oxidative stress depends on identifying DNA oxidation products, their location in the genome, and their interaction with repair, replication, and gene expression.

Nucleotide-Resolution Genome-Wide Mapping of Oxidative DNA Damage by Click-Code-Seq.

Single-nucleotide-resolution sequencing of DNA damage is required to decipher the complex causal link between the identity and location of DNA adducts and their biological impact. However, the low abundance and inability to specifically amplify DNA damage hinders single-nucleotide mapping of adducts within whole genomes. Despite the high biological relevance of guanine oxidation and seminal recent advances in sequencing bulky adducts, single-nucleotide-resolution whole genome mapping of oxidative damage is not yet realized. We coupled the specificity of repair enzymes with the efficiency of a click DNA ligation reaction to insert a biocompatible locator code, enabling high-throughput, nucleotide-resolution sequencing of oxidative DNA damage in a genome. We uncovered thousands of oxidation sites with distinct patterns related to transcription, chromatin architecture, and chemical oxidation potential. Click-code-seq overcomes barriers to DNA damage sequencing and provides a new approach for generating comprehensive, sequence-specific information about chemical modification patterns in whole genomes.

Low Serum Levels of Pre-Surgical Total Cholesterol are Associated with Unfavorable Overall Survival in Patients with Operable Non-Small Cell Lung Cancer.

BACKGROUND: Cholesterol is an essential building block of the cell membrane and an important molecule for cell signaling and function. The dysregulation of cholesterol metabolism has been linked to several diseases, including cancer. The aim of this study is to investigate whether serum cholesterol is associated with the survival outcomes of patients with non-small cell lung cancer (NSCLC). METHODS: The concentration of total cholesterol (TC) was measured in pre-operative serum samples of 637 NSCLC patients. The associations of TC with recurrence and overall survival were analyzed using a Cox proportional hazard regression model. Kaplan-Meier survival curves were calculated for overall survival analysis. RESULTS: Our analyses showed that low serum levels of TC were associated with an increased risk of death. The association between TC and overall survival remained significant after patient age at diagnosis, gender, disease stage, histotype, tumor grade, body mass index (BMI), and smoking status were adjusted in the analysis. The patients with low serum TC had a 61% (95% confidence interval: 1.18 - 2.19) higher risk of death compared to those with normal TC. A Kaplan-Meier survival analysis showed similar results. No association was found between TC and recurrence in NSCLC. CONCLUSIONS: Our study suggests that the pre-surgical serum level of TC may be an independent prognostic indicator for NSCLC overall survival.

Regenerating Family Member 4 (Reg4) Enhances 5-Fluorouracil Resistance of Gastric Cancer Through Activating MAPK/Erk/Bim Signaling Pathway.

BACKGROUND Reg4, a member of the Reg multigene family, is highly upregulated in many gastrointestinal cancers including gastric cancer (GC). The enhanced expression of Reg4 is associated with the resistance of GC to 5-fluorouracil (5-FU), while the underlying mechanism is not clear. The aim of the present study was to explore the resistant mechanism underlying 5-FU resistance. MATERIAL AND METHODS Reg4 expression was assessed by Western blot analysis for SGC-7901, BGC-823, AGS, MKN28, and MKN45. Synthetic short single strand RNA oligonucleotides and Flag-Reg4 plasmid were used to investigate the biological function of Reg4 in vitro. The cell viability assay was performed by MTT. Flow cytometry was carried out to measure the apoptosis caused by 5-FU. Reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) was used to examine the expression of 5-FU metabolism related enzymes. The effect of Reg4 on intracellular signaling was evaluated by Western blot. RESULTS Western blot analysis of 5 GC cells showed that Reg4 was low or null in SGC-7901 and BGC-823, while high in AGS, MKN28, and MKN45. Over-expression of flag-Reg4 in SGC-7901 led to an increase in cell viability and lower apoptosis with 5-FU treatment. In contrast, siRNA knockdown of Reg4 enhanced 5-FU induced apoptosis. However, over-expression or knockdown of Reg4 had no significant influence on the expression of 5-FU metabolic enzymes. Further investigation revealed that Reg4 could activate Erk1/2-Bim-caspase3 cascade. CONCLUSIONS Reg4 inhibited apoptosis through regulating MAPK/Erk/Bim signaling pathway and thereby enhanced the resistance of GC to 5-FU.

Tumor-Infiltrating CD4+ Lymphocytes Predict a Favorable Survival in Patients with Operable Esophageal Squamous Cell Carcinoma.

BACKGROUND The immune status within the tumor microenvironment has not been well determined in esophageal squamous cell carcinoma (ESCC). The aim of this study was to investigate the distributions of tumor-infiltrating T lymphocytes (TILs), and analyze their associations with clinical characteristics and prognosis; as well as investigate the expression of programmed death-ligand 1 (PD-L1) which has been identified as a favorable indicator of prognosis in our previous study on ESCC. MATERIAL AND METHODS Five hundred and thirty-six patients who underwent radical surgery for ESCC between January 2008 and April 2012 in Department of Thoracic Surgery at Zhejiang Cancer Hospital were included in the study. Immunohistochemistry was used to investigate the infiltration of various TILs (CD3+, CD4+, CD8+ T lymphocytes) in ESCC tissues. Chi-square test and Cox proportional hazards regression were used to explore the correlations between TILs abundance and clinicopathological variables and survival. RESULTS The infiltration of intraepithelial CD4+ (iCD4+) lymphocytes was markedly higher than it in the stromal region (44.2% for intraepithelial versus 28.9% for stromal, p<0.001). Moreover, increased iCD4+ lymphocytes were significantly associated with longer overall survival (OS, p=0.001) in univariate analysis and were identified as an independent predictor for improved OS in multivariate analysis (hazard ratio [HR]=0.67, 95% confidence interval [CI]: 0.51-0.88, p=0.040). Neither the infiltration of CD3+ nor CD8+ lymphocytes showed the prognostic value in ESCC (p>0.05). Unexpectedly, combined with our previous study results, the TILs infiltration in ESCC showed an inverse association with the expression of PD-L1 (p=0.027). CONCLUSIONS Our results suggested that iCD4+ lymphocytes infiltration could be a favorable indicator for prognosis in ESCC.

A Nomogram to Predict Brain Metastases of Resected Non-Small Cell Lung Cancer Patients.

PURPOSE: Brain metastasis is a major cause leading to the failure of treatment management for non-small cell lung cancer (NSCLC) patients. The goal of this study was to establish an effective nomogram for prediction of brain metastases of resected NSCLC patients. METHODS: We retrospectively investigated 637 operable NSCLC patients who received treatment at Zhejiang Cancer Hospital, China. A Cox proportional hazards regression model was performed to identify significant risk factors, and a nomogram was developed for predicting 3- and 5-year brain metastases rates. RESULTS: Multivariate analysis identified four independent risk factors: neuron-specific enolase, histological type, number of metastatic lymph nodes, and tumor grade, and a nomogram was developed based on these factors. The effectiveness of the nomogram was validated using an internal bootstrap resampling approach, showing that the nomogram exhibited a sufficient level of discrimination according to the C-index (0.74, 95 % confidence interval 0.67-0.82). CONCLUSIONS: The nomogram developed in this study demonstrated its discrimination capability for predicting 3- and 5-year occurrence of brain metastases, and can be used to identify high-risk patients.

Down Expression of FBP1 Is a Negative Prognostic Factor for Non-Small-Cell Lung Cancer.

Downregulation of fructose-1,6-bisphosphatse-1 (FBP1) was observed in several cancers but its role in the lung cancer still remains unknown. We examined the cancer tissues from 140 patients with nonsmall cell lung cancer patients and found that the relative gene expression of FBP1 was significantly lower in lung cancer tissues as compared to incisal marginal tissues and normal tissues. The patients with higher level of FBP1 RNA expression have significantly longer disease free survival and overall survival as compared to the lower expression groups. There was a negative correlation with the level of FBP1 and recurrence of the lung cancer.

Bioorthogonal SERS Nanoprobes for Mulitplex Spectroscopic Detection, Tumor Cell Targeting, and Tissue Imaging.

A surface-enhanced Raman scattering (SERS) technique shows extraordinary features for a range of biological and biomedical applications. Herein, a series of novel bioorthogonal SERS nanoprobes were constructed with Gold nanoflower (AuNF) and Raman reporters, the signals of which were located in a Raman-silent region of biological samples. AS1411 aptamer was also co-conjugated with AuNF through a self-assembled monolayer coverage strategy. Multiplex SERS imaging using these nanoprobes with three different bioorthogonal small-molecule Raman reporters is successfully achieved with high multiplexing capacity in a biologically Raman-silent region. These Raman nanoprobes co-conjugated with AS1411 showed high affinity for tumor cells with overexpressed nucleolin and can be used for selective tumor cell screening and tissue imaging.

Caged circular antisense oligonucleotides for photomodulation of RNA digestion and gene expression in cells.

We synthesized three 20 mer caged circular antisense oligodeoxynucleotides (R20, R20B2 and R20B4) with a photocleavable linker and an amide bond linker between two 10 mer oligodeoxynucleotides. With these caged circular antisense oligodeoxynucleotides, RNA-binding affinity and its digestion by ribonuclease H were readily photomodulated. RNA cleavage rates were upregulated ~43-, 25- and 15-fold for R20, R20B2 and R20B4, respectively, upon light activation in vitro. R20B2 and R20B4 with 2- or 4-nt gaps in the target RNA lost their ability to bind the target RNA even though a small amount of RNA digestion was still observed. The loss of binding ability indicated promising gene photoregulation through a non-enzymatic strategy. To test this strategy, three caged circular antisense oligonucleotides (PS1, PS2 and PS3) with 2'-OMe RNA and phosphorothioate modifications were synthesized to target GFP expression. Upon light activation, photomodulation of target hybridization and GFP expression in cells was successfully achieved with PS1, PS2 and PS3. These caged circular antisense oligonucleotides show promising applications of photomodulating gene expression through both ribonuclease H and non-enzyme involved antisense strategies.

Synthesis of site-specifically phosphate-caged siRNAs and evaluation of their RNAi activity and stability.

A complete set of new photolabile nucleoside phosphoramidites were synthesized, then site-specifically incorporated into sense or antisense strands of siRNA for phosphate caging. Single caging modification was made along siRNA strands and their photomodulation of gene silencing were examined by using the firefly luciferase reporter gene. Several key phosphate positions were then identified. Furthermore, multiple caging modifications at these key positions led to significantly enhanced photomodulation of gene silencing activity, suggesting a synergistic effect. The caging group on both the terminally phosphate-caged siRNA and the single-stranded caged RNA has comparatively high stability, whereas hydrolysis of the caged group from the internally caged siRNA was observed, irrespective of the presence of Mg(2+). Molecular dynamic simulations demonstrated that enhanced hydrolysis of the caging group on internally phosphate-caged siRNAs was due to easy fragmentation of the caging group upon formation of the pentavalent intermediate of the phosphotriester with attack by water. The caging group in the terminally phosphate-caged siRNA or single-stranded caged RNA prefers to form π-π stacks with nearby nucleobases. In addition to providing explanations for previous observations, this study sheds further light on the design of caged oligonucleotides and indicates the direction of future development of nucleic acid drugs with phosphate modifications.

Kindlin 2 forms a transcriptional complex with ß-catenin and TCF4 to enhance Wnt signalling.

Kindlin 2, as a focal adhesion protein, controls integrin activation. However, the association of Kindlin 2 with cancer-related signalling pathways is unknown. Here we identified a new direct interaction between Kindlin 2 and the active ß-catenin. Importantly, Kindlin 2 forms a tripartite complex with ß-catenin and TCF4. Mechanistically, Kindlin 2 selectively strengthens the occupancy of ß-catenin on the Wnt target gene Axin2 and enhances Axin2 gene expression. Functionally, the ß-catenin-Axin2-Snail cascade is required for Kindlin 2-induced tumour cell invasion. Our data indicate that Kindlin 2 is a new regulator of Wnt signalling, providing a mechanistic insight into the role of Kindlin 2 in cancer progression.

Candidate prognostic biomarkers and prediction models for high-grade serous ovarian cancer from urinary proteomics.

High-grade serous ovarian cancer (HGSOC) is one of the most common histologic types of ovarian cancer. The purpose of this study was to identify potential prognostic biomarkers in urine specimens from patients with HGSOC. First, 56 urine samples with information on relapse-free survival (RFS) months were collected and classified into good prognosis (RFS ≥ 12 months) and poor prognosis (RFS < 12 months) groups. Next, data-independent acquisition (DIA)-based mass spectrometry (MS) analysis was combined with MSFragger-DIA workflow to identify potential prognostic biomarkers in a discovery set (n = 31). With the aid of parallel reaction monitoring (PRM) analysis, four candidate biomarkers (ANXA1, G6PI, SPB3, and SPRR3) were finally validated in both the discovery set and an independent validation set (n = 25). Subsequent RFS and Cox regression analyses confirmed the utility of these candidate biomarkers as independent prognostic factors affecting RFS in patients with HGSOC. Regression models were constructed to predict the 12-month RFS rate, with area under the receiver operating characteristic curve (AUC) values ranging from 0.847 to 0.905. Overall, candidate prognostic biomarkers were identified in urine specimens from patients with HGSOC and prediction models for the 12-month RFS rate constructed. SIGNIFICANCE: OC is one of the leading causes of death due to gynecological malignancies. HGSOC constitutes one of the most common histologic types of OC with aggressive characteristics, accounting for the majority of advanced cases. In cases where patients with advanced HGSOC potentially face high risk of unfavorable prognosis or disease advancement within a 12-month period, intensive medical monitoring is necessary. In the era of precision cancer medicine, accurate prediction of prognosis or 12-month RFS rate is critical for distinguishing patient groups requiring heightened surveillance. Patients could significantly benefit from timely modifications to treatment regimens based on the outcomes of clinical monitoring. Urine is an ideal resource for disease surveillance purposes due to its easy accessibility. Furthermore, molecules excreted in urine are less complex and more stable than those in other liquid samples. In the current study, we identified candidate prognostic biomarkers in urine specimens from patients with HGSOC and constructed prediction models for the 12-month RFS rate.

tRNA modification profiling reveals epitranscriptome regulatory networks in Pseudomonas aeruginosa.

Transfer RNA (tRNA) modifications have emerged as critical posttranscriptional regulators of gene expression affecting diverse biological and disease processes. While there is extensive knowledge about the enzymes installing the dozens of post-transcriptional tRNA modifications - the tRNA epitranscriptome - very little is known about how metabolic, signaling, and other networks integrate to regulate tRNA modification levels. Here we took a comprehensive first step at understanding epitranscriptome regulatory networks by developing a high-throughput tRNA isolation and mass spectrometry-based modification profiling platform and applying it to a Pseudomonas aeruginosa transposon insertion mutant library comprising 5,746 strains. Analysis of >200,000 tRNA modification data points validated the annotations of predicted tRNA modification genes, uncovered novel tRNA-modifying enzymes, and revealed tRNA modification regulatory networks in P. aeruginosa . Platform adaptation for RNA-seq library preparation would complement epitranscriptome studies, while application to human cell and mouse tissue demonstrates its utility for biomarker and drug discovery and development.

Kindlin 2 promotes breast cancer invasion via epigenetic silencing of the microRNA200 gene family.

Kindlin 2, as a focal adhesion protein, controls integrin activation and regulates Wnt signaling in an integrin-binding independent manner. However, the association of Kindlin 2 with cancer-related microRNAs is unknown. Here, we report that Kindlin 2 markedly downregulates the expression of miR-200 family by inducing CpG island hypermethylation. Mechanistically, Kindlin 2 forms a complex with DNMT3A in the cell nucleus and the two proteins co-occupy the promoter of miRNA-200b. Functionally, repression of miR-200b is required for Kindlin 2-induced breast cancer cell invasion and tumor formation. Our data indicate that Kindlin 2 plays a novel role in epigenetic repression of miR-200 family, a mechanism that promotes breast cancer invasion.