Jingyan Xue

Induction of miRNA-181a by genotoxic treatments promotes chemotherapeutic resistance and metastasis in breast cancer

Acquired therapeutic resistance is the major drawback to effective systemic therapies for cancers. Aggressive triple-negative breast cancers (TNBC) develop resistance to chemotherapies rapidly, whereas the underlying mechanisms are not completely understood. Here we show that genotoxic treatments significantly increased the expression of miR-181a in TNBC cells, which enhanced TNBC cell survival and metastasis upon Doxorubicin treatment. Consistently, high miR-181a level associated with poor disease free survival and overall survival after treatments in breast cancer patients. The upregulation of miR-181a was orchestrated by transcription factor STAT3 whose activation depended on NF-κB-mediated IL-6 induction in TNBC cells upon genotoxic treatment. Intriguingly, activated STAT3 not only directly bound to MIR181A1 promoter to drive transcription but also facilitated the recruitment of MSK1 to the same region where MSK1 promoted a local active chromatin state by phosphorylating histone H3. We further identified BAX as a direct functional target of miR-181a, whose suppression decreased apoptosis and increased invasion of TNBC cells upon Dox treatment. These results were further confirmed by evidence that suppression of miR-181a significantly enhanced therapeutic response and reduced lung metastasis in a TNBC orthotopic model. Collectively, our data suggested that miR-181a induction had a critical role in promoting therapeutic resistance and aggressive behavior of TNBC cells upon genotoxic treatment. Antagonizing miR-181a may serve as a promising strategy to sensitize TNBC cells to chemotherapy and mitigate metastasis.

USP10 inhibits genotoxic NF-κB activation by MCPIP1-facilitated deubiquitination of NEMO

DNA damage‐induced activation of the transcription factor NF‐κB plays an important role in the cellular response to genotoxic stress. However, uncontrolled NF‐κB activation upon DNA damage may lead to deleterious consequences. Although the mechanisms mediating genotoxic NF‐κB activation have been elucidated, how this signalling is terminated remains poorly understood. Here, we show that the CCCH‐type zinc finger‐containing protein MCPIP1 (monocyte chemotactic protein‐1‐induced protein‐1; also known as ZC3H12A) is induced upon genotoxic treatment in an NF‐κB‐dependent manner. MCPIP1 upregulation reduces NEMO linear ubiquitylation, resulting in decreased activation of IKK and NF‐κB. NEMO ubiquitylation is decreased through the deubiquitinase USP10, which interacts with NEMO via MCPIP1 upon genotoxic stress. USP10 association with NEMO leads to removal of NEMO‐attached linear polyubiquitin chains and subsequent inhibition of the genotoxic NF‐κB signalling cascade. Consistently, USP10 is required for MCPIP1‐mediated inhibition of genotoxic NF‐κB activation and promotion of apoptosis. Thus, by mediating USP10‐dependent deubiquitination of NEMO, MCPIP1 induction serves as a negative feedback mechanism for attenuating genotoxic NF‐κB activation.

MiRNA-621 sensitizes breast cancer to chemotherapy by suppressing FBXO11 and enhancing p53 activity

MicroRNAs (miRNAs) have been demonstrated to have critical roles in regulating cancer cell proliferation, survival and sensitivity to chemotherapy. The potential application of using miRNAs to predict therapeutic response to cancer treatment holds high promise, but miRNAs with predictive value remain to be identified and underlying mechanisms have not been completely understood. Here, we show a strong correlation between miR-621 expression and chemosensitivity to paclitaxel plus carboplatin (PTX/CBP) regimen, an effective neoadjuvant chemotherapy for breast cancer patients. High level of miR-621 predicts better response to PTX/CBP regimen neoadjuvant chemotherapy in breast cancer patients, who also tend to achieve pathological complete response. Ectopic overexpression of miR-621 promoted apoptosis and increased chemosensitivity to PTX and CBP both in cultured breast cancer cells and in xenograft tumor model. We further show that FBXO11 is a direct functional target of miR-621 and miR-621 level is negatively correlated with FBXO11 expression in breast cancer patients. Ectopic expression of FBXO11 attenuated increased apoptosis in breast cancer cells overexpressing miR-621 upon PTX or CBP treatment. Consistently, high FBXO11 expression significantly correlated with poor survival in breast cancer patients. Mechanistically, we found in breast cancer cells FBXO11 interacts with p53 and promotes its neddylation, which suppressed the p53 transactivity. Accordingly, miR-621-dependent FBXO11 suppression enhanced p53 activity and increased apoptosis in breast cancer cells exposed to chemotherapeutics. Taken together, our data suggest that miR-621 enhances chemosensitivity of breast cancer cells to PTX/CBP chemotherapy by suppressing FBXO11-depedent inhibition of p53. miR-621 may serve as a predictive biomarker and a potential therapeutic target in breast cancer treatment.

MicroRNAs in cancer therapeutic response: Friend and foe

Cancer initiation and development engage extremely complicated pathological processes which involve alterations of a large number of cell signaling cascades and functional networks in temporal and spatial orders. During last decades, microRNAs (miRNAs), a class of non-coding RNAs, have emerged as critical players in cancer pathogenesis and progression by modulating many pathological aspects related to tumor development, growth, metastasis, and drug resistance. The major function of miRNAs is to post-transcriptionally regulate gene expression depending on recognition of complementary sequence residing in target mRNAs. Commonly, a particular miRNA recognition sequence could be found in a number of genes, which allows a single miRNA to regulate multiple functionally connected genes simultaneously and/or chronologically. Furthermore, a single gene can be targeted and regulated by multiple miRNAs. However, previous studies have demonstrated that miRNA functions are highly context-dependent, which leads to distinct pathological outcomes in different types of cancer as well as at different stages by alteration of the same miRNA. Here we summarize recent progress in studies on miRNA function in cancer initiation, metastasis and therapeutic response, focusing on breast cancer. The varying functions of miRNAs and potential application of using miRNAs as biomarkers as well as therapeutic approaches are further discussed in the context of different cancers.

Long non-coding RNA metastasis associated in lung adenocarcinoma transcript 1 (MALAT1) interacts with estrogen receptor and predicted poor survival in breast cancer

Metastasis associated in lung adenocarcinoma transcript 1 (MALAT1), a lncRNA that was first recognized as a prognostic parameter for patient survival of stage I lung cancer, is up-regulated in multiple human malignancies, including breast cancer. However, the mechanism of its function remained elusive. In the current study, by examining MALAT1 expression on mRNA level, we demonstrated that compared with MCF10A, MALAT1 expression was up-regulated in the majority of breast cancer cell lines (9/12). In 26 pairs of estrogen receptor (ER)-positive breast cancer samples, MALAT1 expression was significantly up-regulated compared with adjacent normal tissues (P = 0.012). Furthermore, of 204 breast cancer patients, high MALAT1 expression was associated with positive ER (P = 0.023) and progesterone receptor (PR) (P = 0.024) status. Further analysis using TCGA database revealed that ER and its target genes PGR and CCND1, were overexpressed in MALAT1 altered group compared with unaltered group, both on the mRNA and protein level. Lastly, we verified MALAT1s prognostic value in breast cancer. At the cut-off value of 75%, MALAT1 was the only independent prognostic factor of recurrence-free survival (RFS) in ER-negative patients in a multivariate Cox regression model (hazard ratio [HR] = 2.83, 95% confidence interval [CI] 1.02–7.83). MALAT1 overexpression was also associated with poor RFS in tamoxifen treated ER-positive breast cancer patients, which might serve as a potential biomarker to predict endocrine treatment sensitivity.

PPAR signaling pathway may be an important predictor of breast cancer response to neoadjuvant chemotherapy

PurposeNeoadjuvant chemotherapy for advanced breast cancer may improve the radicality for a subset of patients, but others may suffer from severe adverse drug reactions without any benefit. To predict the responses to chemotherapy, we performed a phase II trial of neoadjuvant chemotherapy using a weekly PCb [paclitaxel (Taxol) plus carboplatin] regimen for stage II/III breast cancer and assessed the correlation between baseline gene expression and the tumor response to treatment.MethodsA total of 61 patients with stage II-III breast cancer were included and administered four cycles of preoperative PCb. We performed a gene expression analysis using Affymetrix HG-U133 Plus 2.0 GeneChip arrays in 31 breast cancer tissues. Differentially expressed genes (DEGs) were identified by the significance analysis of microarrays (SAM) program using a false discovery rate of 0.05. The Functional Annotation Tool in the DAVID Bioinformatics Resources was used to perform the gene functional enrichment analysis. The other 30 patients (15 pCR and 15 non-pCR patients) were available as an independent validation set to test the selected DEGs by quantitative real-time PCR analysis (qRT-PCR).ResultsBy analyzing six pathological complete response (pCR) patients and 25 patients with non-pCR, 300 probes (231 genes) were identified as differentially expressed between pCR and residual disease by the SAM program when the fold change was >2. The gene functional enrichment analysis revealed 15 prominent gene categories that were different between pCR and non-pCR patients, most notably the genes involved in the peroxisome proliferator-activated receptor (PPAR), DNA repair and ER signal pathways and in the immune-related gene cluster. The qRT-PCR analysis results for the genes in the PPAR pathway (LPL, SORBS1, PLTP, SCD5, MMP1 and CSTA) in independent validation set were consistent with the results from the microarray data analysis.ConclusionIn the present study, we identified a number of gene categories pertinent to the therapeutic response. We believe that the PPAR pathway may be an important predictor of genes that are involved in the chemotherapy response.

Efficacy and safety of docetaxel combined with oxaliplatin as a neoadjuvant chemotherapy regimen for Chinese triple-negative local advanced breast cancer patients: A prospective, open, and unicentric phase II clinical trial

Background and Aims:To determine the efficacy and toxicity of an oxaliplatin-based regimen as a neoadjuvant chemotherapy setting in triple-negative local advanced breast cancer (TNLABC) patients. Methods:Patients with stage IIIb or IIIc, chemotherapy-naive TNLABC receive docetaxel 75 mg/m2 day 1 and oxaliplatin 130 mg/m2 day 2, every 21 days for up to 4 cycles. The primary end point is pathologic complete response (CR), and the secondary end points are clinical response (including CR and partial response), disease-free survival, overall survival, and safety. Results:Twenty-nine TNLABC patients were treated: 17(58.62%) had stage IIIB disease and 12 (41.38%) had stage IIIC disease. After neoadjuvant chemotherapy, there were 10 patients (34.48%) with pathologic CR (95% confidence interval, 21.51%-48.70%). Twenty patients responded (7 CR and 13 partial response) with a 68.97% total clinical response rate (95% confidence interval 57.51%-88.02%). Nearly 27.59% patients (8 patients) had disease progression after at least 2 cycles of chemotherapy, and only 1 patient (3.45%) had the disease stable, respectively. In the 29 treated patients, there were no unusual or unexpected adverse events in a total of 91 cycles for the chemotherapy setting. Common grade 3 or 4 hematologic toxicities were leukocytopenia, which occured in 4 TNLABC patients (13.79%), and thrombocytopenia in 1 patient (3.45%). Grade 3 or 4 transaminase elevation occured in 5 (17.24%) patients and grade 3 vomiting occured in 1(3.45%) patient. One patient experienced grade 3 neurosensory toxicities. There are 5 reports (17.24%) of grade 3 fatigue. Conclusions:The results of this phase II clinical study suggest that docetaxel combined with oxaliplatin as a neoadjuvant chemotherapy regimen in TNLABC patients is active and well tolerated, and should be further investigated as a favorable treatment alternative for TNLABC patients. A large randomized prospective clinical study is warranted to confirm the results.

Phosphorylated eIF2α predicts disease-free survival in triple-negative breast cancer patients

Phosphorylated eukaryotic translation initiation factor 2α (p-eIF2α), which functions as a marker of endoplasmic reticulum stress, has been reported to be associated with patient prognosis in various cancers. However, little is known about the prognostic value of p-eIF2α in breast cancer, particularly in different breast cancer subtypes. An immunohistochemistry screen for p-eIF2α was performed using a tissue microarray containing 233 tumors and paired peritumoral tissues from female patients diagnosed with breast cancer. The staining results were scored semiquantitatively, and the p-eIF2α expression level in breast cancer and its potential prognostic value were investigated. In this retrospective cohort study, we found that p-eIF2α levels were significantly upregulated in breast cancer (P < 0.001). p-eIF2α level was negatively correlated with lymph node status (P = 0.039). Survival analysis by Kaplan–Meier estimation and Cox regression showed that p-eIF2α level was correlated with better disease free survival (P = 0.026) and served as an independent prognostic factor (P = 0.046) in patients with triple-negative breast cancer. Our study revealed that p-eIF2α was upregulated in breast cancer and represented a novel predictor of prognosis in patients with triple-negative subtype.

Long non-coding RNA00544 serves as a potential novel predictive and prognostic marker for HR+ HER2− subtype breast cancer

Luminal breast cancers (BC) account for majority of breast cancer. Due to its heterogeneity and the development of treatment resistance, luminal BC patients can vary substantially. Long noncoding RNAs (lncRNAs), as we known, is involved in breast cancer progression. Here, we aim to identify the lncRNAs which are involved in the particular type luminal BC progression. By Gene Chips analysis, we found a novel lncRNA00544, which was highly expressed in the metastatic axillary nodes compared with corresponding luminal BC tissues (fold change = 2.26, P = 0.043). This result was confirmed in luminal BC cell lines (p = 0.0113) and 49 paired breast cancer samples compared with in corresponding controls (p = 0.011). Furthermore, Kaplan–Meier survival curves of 373 breast cancer patients indicated that disease-free survival was significantly poor in breast cancer patients with high lncRNA00544 expression (p < 0.001). Univariate and multivariate Cox regression analyses showed that lncRNA00544 was a significant independent prognostic biomarker in luminal BC patients. Further analysis showed that the prognosis of high lncRNA00544 expression in breast cancer patients was actually related to HR + HER2− subtype. Together, our studies indicate that lncRNA00544 may represent a novel predictive and prognostic indicator in luminal BC patients.

Abstract P3-02-01: Pre-operative breast MRI would not benefit breast cancer patients' survival, even in young patients treated with breast-conservative surgery

Background Although breast magnetic resonance imaging (MRI) could help to identify occult lesions in breast cancer, its role in patient outcome has always been controversial. The current study aimed to evaluate the role of MRI in Asian breast cancer patients, especially young patients that might have dense breasts. Methods Patients with non-metastatic unilateral breast cancer who received surgery in our institute during 2007-2013 were retrospectively reviewed. The differences between groups were compared using Pearson9s χ2 test.Loco-regional recurrence-free survival (LRRFS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier method. Results A total of 13,681 patients were included into analysis, among which 5823 (42.6%) had pre-operative MRI. Of all patients, 39.7% were stage 0-I according to TNM system, 35.5% were stage II, 14.8% were stage III and 10.0% could not be staged. Patients with axillary lymph node metastasis were comparable in MRI and non-MRI groups (35.3% versus 35.6%, P=0.695). The percentile of patients receiving MRI increased from 7.3% in 2007 to 67.5% in 2013. Patients in the breast-conservative surgery (BCS) group were more likely to receive MRI compared with the mastectomy group (P Age and menopausal status were also related with the choice of pre-operative MRI. When patients were grouped according to age, 56.7%, 48.9%, 43.6%, 37.0% and 27.1% patients in the ≤35, 36-45, 46-55, 56-65 and >65 years old group had MRI, respectively (P In survival analysis, the average follow-up time for the MRI group (N=5823) and non MRI group (N=7858) were 88.5 and 114.4 months, during which 238 (4.1%) and 464 (5.9%) breast cancer recurrences occurred, while 63 (1.1%) and 159 (2.0%) loco-reginal recurrences occurred. The estimated 5-year RFS for MRI group and non-MRI group were 90.1% and 90.0% (P=0.510). The 5-year LRR-free survival LRRFS for MRI group and non-MRI group were 96.7% and 97.3% (P=0.128). In subgroup analysis, 2376 patients received BCS, and 11,035 received mastectomy. Patient in the pre-operative MRI group did not have superior RFS or LRRFS compared with the non-MRI group, regardless of surgical management (BCS versus mastectomy). Then we restrained the analysis to patients who were ≤45 years old and treated with BCS. A total of 699 patients had pre-operative MRI, and 419 patients did not. The 5-year RFS for MRI group and non-MRI group were 95.8% versus 94.6% (P=0.231); the 5-year LRRFS for MRI group and non-MRI group were 99.8% and 97.1% (P=0.144). Conclusions There was an increasing trend of pre-operative MRI examination during 2007-2013, especially in young patients and patients treated with BCS. However, pre-operative MRI could not benefit breast cancer patients9 survival by detecting occult lesions, even in young patients treated with BCS, who were considered to have dense breasts. Citation Format: Huang N, Chen J, Yang B, Quan C, Xue J, Huang X, Wu J. Pre-operative breast MRI would not benefit breast cancer patients9 survival, even in young patients treated with breast-conservative surgery [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-02-01.