LncRNA PRBC induces autophagy to promote breast cancer progression through modulating PABPC1-mediated mRNA stabilization.

Breast cancer is one of the major malignant tumors among women worldwide. Long noncoding RNAs (lncRNAs) have been documented as significant modulators in the development and progression of various cancers; however, the contribution of lncRNAs to breast cancer remains largely unknown. In this study, we found a novel lncRNA (NONHSAT137675) whose expression was significantly increased in the breast cancer tissues. We named the novel lncRNA as lncRNA PRBC (PABPC1-related lncRNA in breast cancer) and identified it as a key lncRNA associated with breast cancer progression and prognosis. Functional analysis displayed that lncRNA PRBC could promote autophagy and progression of breast cancer. Mechanistically, we verified that lncRNA PRBC physically interacted with PABPC1 through RIP assay, and PABPC1 overexpression could reverse the inhibiting effect of lncRNA PRBC knockdown on the malignant behaviors in breast cancer cells. Knockdown of lncRNA PRBC interfered the translocation of PABPC1 from nucleus to cytoplasm as indicated by western blot and IF assays. Significantly, the cytoplasmic location of PABPC1 was required for the interaction between PABPC1 and AGO2, which could be enhanced by lncRNA PRBC overexpression, leading to strengthened recruitment of mRNA to RNA-induced silencing complex (RISC) and thus reinforcing the inhibition efficiency of miRNAs. In general, lncRNA PRBC played a critical role in malignant progression of breast cancer by inducing the cytoplasmic translocation of PABPC1 to further regulate the function of downstream miRNAs. This study provides novel insight on the molecular mechanism of breast cancer progression, and lncRNA PRBC might be a promising therapeutic target and prognostic predictor for breast cancer.

HSPB1 facilitates chemoresistance through inhibiting ferroptotic cancer cell death and regulating NF-κB signaling pathway in breast cancer.

Chemoresistance is one of the major causes of therapeutic failure and poor prognosis for breast cancer patients, especially for triple-negative breast cancer patients. However, the underlying mechanism remains elusive. Here, we identified novel functional roles of heat shock protein beta-1 (HSPB1), regulating chemoresistance and ferroptotic cell death in breast cancer. Based on TCGA and GEO databases, HSPB1 expression was upregulated in breast cancer tissues and associated with poor prognosis of breast cancer patients, which was considered an independent prognostic factor for breast cancer. Functional assays revealed that HSPB1 could promote cancer growth and metastasis in vitro and in vivo. Furthermore, HSPB1 facilitated doxorubicin (DOX) resistance through protecting breast cancer cells from drug-induced ferroptosis. Mechanistically, HSPB1 could bind with Ikß-α and promote its ubiquitination-mediated degradation, leading to increased nuclear translocation and activation of NF-κB signaling. In addition, HSPB1 overexpression led to enhanced secretion of IL6, which further facilitated breast cancer progression. These findings revealed that HSPB1 upregulation might be a key driver to progression and chemoresistance through regulating ferroptosis in breast cancer while targeting HSPB1 could be an effective strategy against breast cancer.

Cancer-associated fibroblasts facilitate breast cancer progression through exosomal circTBPL1-mediated intercellular communication.

Breast cancer is the major common malignancy worldwide among women. Previous studies reported that cancer-associated fibroblasts (CAFs) showed pivotal roles in regulating tumor progression via exosome-mediated cellular communication. However, the detailed mechanism underlying the exosomal circRNA from CAFs in breast cancer progression remains ambiguous. Here, exosomal circRNA profiling of breast cancer-derived CAFs and normal fibroblasts (NFs) was detected by high-throughput sequencing, and upregulated circTBPL1 expression was identified in CAF exosomes. The exosomal circTBPL1 from CAFs could be transferred to breast cancer cells and promoted cell proliferation, migration, and invasion. Consistently, circTBPL1 knockdown in CAFs attenuated their tumor-promoting ability. Further exploration identified miR-653-5p as an inhibitory target of circTBPL1, and ectopic expression of miR-653-5p could partially reverse the malignant phenotypes induced by circTBPL1 overexpression in breast cancer. Additionally, TPBG was selected as a downstream target gene, and circTBPL1 could protect TPBG from miR-653-5p-mediated degradation, leading to enhanced breast cancer progression. Significantly, the accelerated tumor progression triggered by exosomal circTBPL1 from CAFs was confirmed in xenograft models. Taken together, these results revealed that exosomal circTBPL1 derived from CAFs contributed to cancer progression via miR-653-5p/TPBG pathway, indicating the potential of exosomal circTBPL1 as a biomarker and novel therapeutic target for breast cancer.

A novel ferroptosis­related gene signature for overall survival prediction and immune infiltration in patients with breast cancer.

Breast cancer is the most prevalent type of cancer among women worldwide. The heterogeneous nature of breast cancer poses a serious challenge for prognostic prediction and individualized therapies. Recently, ferroptosis, an iron­dependent form of programmed cell death, has been reported to serve a significant role in the regulation of the biological behavior of tumors. Several studies have revealed the prognostic significance of the ferroptosis­related gene (FRG) model; however, additional efforts are required to elucidate the details. Moreover, genes that modulate ferroptosis may be promising candidate bioindicators in cancer therapy. The present study systematically assessed the expression profiles of FRGs to reveal the relationship between FRGs and the prognostic features of patients with breast cancer based on data obtained from the Gene Expression Omnibus and Molecular Taxonomy of Breast Cancer International Consortium. Using a non­negative matrix factorization clustering method, patients with breast cancer were classified into two sub­groups (cluster 1 and cluster 2) based on the expression of FRGs. Furthermore, Cox regression, and least absolute shrinkage and selection operator methods were used to construct a risk score formula comprised of nine genes, which stratified patients with breast cancer into two risk groups. Patients belonging to the high­risk group exhibited significantly shorter overall survival (OS) time compared with patients in the low­risk group. The prognostic value of this signature was further verified in the training and validation cohorts. The results for univariate and multivariate Cox regression analyses indicated that risk score acted as an independent predictor for OS. Subsequently, a nomogram was constructed. Receiver operating characteristic analysis further confirmed that the resulting nomogram exhibited powerful discriminatory ability. Functional analysis revealed that the immune environment differed notably between the two groups and indicated an association between ferroptosis and breast cancer proliferation, migration and drug resistance. Taken together, the present study demonstrated that FRGs were significantly associated with breast cancer progression, and thus could be used as novel biomarkers for prognostic prediction and individualized treatment of patients with breast cancer.

Circ-TRIO promotes TNBC progression by regulating the miR-432-5p/CCDC58 axis.

Numerous studies have shown that circRNAs are aberrantly expressed in various cancers and play a significant role in tumor progression. However, the molecular mechanisms of circRNAs in triple-negative breast cancer (TNBC) remain ambiguous. By intersecting throughput data and qRT-PCR results from tissues and cell lines, circ-TRIO was identified as a potential oncogenic regulator of TNBC. Moreover, circ-TRIO expression was detected in TNBC tissues and was correlated with the recurrence and prognosis of TNBC patients. The circular characteristics of circ-TRIO were verified by RNase R and CHX assays. Functionally, the knockdown of circ-TRIO inhibited the proliferation, migration and invasion of TNBC cells, while the overexpression of circ-TRIO resulted in the opposite impacts. Mechanistically, a dual luciferase reporter assay and RNA immunoprecipitation were performed and indicated that circ-TRIO could combine with miR-432-5p to regulate the expression of coiled-coil domain containing 58 (CCDC58). In summary, our study illustrates that circ-TRIO plays an important role in the progression of TNBC by regulating the miR-432-5p/CCDC58 axis, which could broaden our insight into the underlying mechanisms and provide a novel prognostic marker of TNBC in the clinic.

Evaluation of Carbon Nanoparticle Suspension and Methylene Blue Localization for Preoperative Localization of Nonpalpable Breast Lesions: A Comparative Study.

Background: The resection of nonpalpable breast lesions (NPBLs) largely depends on the preoperative localization technology. Although several techniques have been used for the guidance of NPBL resection, more comfortable and effective methods are needed. This aim of this study was to evaluate the use and feasibility of carbon nanoparticle suspension (CNS) and methylene blue (MB)-guided resection of NPBL, to introduce alternative techniques. Methods: A total of 105 patients with 172 NPBLs detected by breast ultrasound were randomized to CNS localization (CNSL) group and MB localization (MBL) group. The injection times of the two groups were divided into 2, 4, 6, 12, 16, and 20 h before surgery. In this study, localization time, stained area, operation time, total resection volume (TRV), calculated resection ratio (CRR), and pathological diagnosis were assessed. Results: All of the 172 lesions were finally confirmed benign. Dye persisted in all cases in the CNSL group (109/109, 100%), while that persisted in only 53 cases in the MBL group (53/63, 84.1%) (P < 0.001). There was a significant correlation between dyeing time and dyeing area in the MBL group (r = -0.767, P < 0.001); however, there was no significant correlation in the CNSL group (r = -0.154, P = 0.110). The operation time was 11.05 ± 3.40 min in the CNSL group and 13.48 ± 6.22 min in the MBL group (P < 0.001). The TRV was 2.51 ± 2.42 cm3 in the CNSL group and 3.69 ± 3.24 cm3 in the MBL group (P = 0.016). For CRR, the CNSL group was lower than the MBL group (7.62 ± 0.49 vs. 21.93 ± 78.00, P = 0.018). There is no dye remained on the skin in the MBL group; however, dye persisted in 12 patients (19.4%) in the CNSL group (P = 0.001). Conclusion: Carbon nanoparticle suspension localization and MBL are technically applicable and clinically acceptable procedures for intraoperatively localizing NPBL. Moreover, given the advantages of CNSL compared to MBL, including the ability to perform this technique 5 days before operation and smaller resection volume, it seems to be a more attractive alternative to be used in intraoperative localization of NPBL.

Application of preoperative computed tomographic lymphography for precise sentinel lymph node biopsy in breast cancer patients.

BACKGROUND: In light of the extensive application of sentinel lymph node biopsy (SLNB) in clinically node-negative breast cancer patients and the recently investigated failure of SLNB after lumpectomy, it has become important to explore methods for preoperative mapping of sentinel lymph nodes (SLNs) and their lymphatics to direct precise SLNB and improve the identification rate of SLNs. METHODS: Twenty-seven patients with suspected breast cancer based on the results of the clinical examination and imaging were enrolled in the study. Computed tomographic lymphography (CTLG) followed by CT three-dimensional reconstruction was performed to determine the localization of SLNs and lymphatics on the body surface preoperatively. Intraoperatively combined staining with methylene blue and indocyanine green was used to evaluate the accuracy and feasibility of CTLG. RESULTS: SLNs and lymphatics from the breast were identified using CTLG in all patients, and preoperative SLNs and lymphatics localization on the body surface showed a significant role in the selection of operative incision and injection points. The accuracy rate of SLN and lymphatic detection by CTLG was 92.6% compared with intraoperatively combined staining. Moreover, preoperative CTLG performed well in SLN number detection, and the accuracy rate was 95.2%. CONCLUSION: We evaluate the procedure and application of preoperative CTLG in the superficial localization of SLNs and lymphatics, which may lead to a decreased incidence of cutting off the lymphatics of SLNs and consequently more rapid and accurate SLN detection. This method promotes personalized SLN mapping, providing detailed information about the number and anatomical location of SLNs and lymphatics for adequate surgical planning for breast cancer patients.

Identification and preservation of stained non-sentinel lymph nodes in breast cancer.

Sentinel lymph nodes (SLNs) are the first lymph nodes that receive lymphatic drainage from the breast. However, all stained lymph nodes are dissected as SLNs during surgery. The present study aimed to identify and preserve the stained non-SLNs and evaluate the safety during sentinel lymph node biopsy (SLNB) in breast cancer. SLNB was performed with a methylene blue and indocyanine green double-tracer technique. The first lymph node, which was connected with lymphatic vessels from the breast, was designated as the true SLN. The lymph node that was directly connected with the output lymphatic duct of the SLN was defined as post-SLN (poSLN), whereas the stained poSLN was designated as non-SLN. Both the stained SLN and non-SLN were sent to the pathological department for definitive diagnosis. The present study demonstrated that intraoperative dissection of the lymphatic network could distinguish true SLNs and stained non-SLNs. The number of stained lymph nodes was time-dependent. Not all stained lymph nodes were real SLNs, whereas the poSLNs would be stained if the staining time interval was inappropriate. The data indicated that the poSLNs were negative for metastasis when the SLNs were negative for metastasis. Stained lymph nodes may contain non-SLNs in addition to SLNs. Resection of all stained lymph nodes is not recommended. To reduce the morbidity due to SLNB complications, the identification and preservation of stained non-SLNs during SLNB is feasible and warrants further study in the era of precision medicine.

Galactogram Grading System for Identifying Breast Cancer With Nipple Discharge.

BACKGROUND: Galactography is a primary recommendation in the management of nipple discharge (ND), which may be caused by benign or malignant lesions. We aimed to establish a galactogram grading system (GGS) and investigate its role in identifying breast cancer with ND. PATIENTS AND METHODS: A total of 350 patients were included in our study. All patients received preoperative mammographic galactography successfully and underwent surgery at Qilu Hospital of Shandong University between January 2011 and August 2015. We first performed a retrospective study in a consecutive series of 250 patients with ND to establish a GGS. Then the subsequent consecutive series of 100 patients was analyzed to validate the grading system. RESULTS: Our data showed that the GGS can well assess the risk of a galactogram's being malignant. Galactograms classified into grade I have a lower risk of being malignant, while those classified into grade III have a higher risk of being malignant. Thus, our GGS was useful for distinguishing malignant from benign lesions. CONCLUSION: We established a scoring system for breast disease with ND. This GGS may be a novel approach for identifying breast cancer with ND.

Clinicopathological features of granulomatous lobular mastitis and mammary duct ectasia.

Granulomatous lobular mastitis (GLM) and mammary duct ectasia (MDE) are inflammatory diseases. However, only a limited number of studies have focused on characterizing their clinicopathological features. The aim of the present study was to investigate the etiology, clinicopathological characteristics and diagnosis of GLM and MDE. The clinical information and treatment of 118 female patients with pathologically-proven GLM or MDE were retrospectively analyzed in the present study. A total of 29 cases had GLM, 77 had MDE and 12 had GLM accompanied by MDE. GLM tends to occur in patients who have had their last birth within 5 years and are usually <40 years of age. GLM masses were usually larger than MDE masses and suppurated or ulcerated more easily. Histopathologically, GLM was characterized by a significant granulomatous inflammatory reaction centered on lobules. Compared with MDE, GLM had a higher incidence of granuloma and microabscess formation within the lobules and surrounding tissue. More multinucleated giant cells within granuloma were observed in patients with GLM than in those with MDE, while MDE was characterized by significant dilatation of the duct terminals and inflammatory changes in the duct wall and periductal tissues. When compared with patients with GLM, foam cells within the duct epithelium or surrounding stroma were more common in patients with MDE. The present study demonstrated that GLM and MDE had distinct clinicopathological characteristics. Further research is required in order to identify more appropriate treatment strategies for these specific types of breast inflammation.

A20 protects neuronal apoptosis stimulated by lipopolysaccharide-induced microglial exosomes.

LPS-induced microglial activation has a major influence on neuronal damage in the inflammatory process. Integral to this is the cellular and molecular interaction between microglia and neurons. Exosomes, a mediator of communication between cells, can transfer lipids, proteins and nucleic acids, affecting many donor and recipient cells. To investigate the mechanism by which microglial exosomes regulate neuronal inflammation after traumatic brain injury, this study primarily analyzed the effect of microglial exosomes on neuronal apoptosis. Exosomes derived from lipopolysaccharide (LPS)-activated microglial cultures were identified and purified. Neurons treated with these exosomes underwent apoptosis. A20 (also known as TNF-inducible protein 3, TNFAIP3) is a deubiquitinating enzyme with key anti-inflammatory functions. A20 is of huge significance to the degeneration and development of neuron. Importantly, A20 protects the exosomes-induced neuronal death, while A20 knockdown increases neuronal death. This study shows that exosomes may be critical for communication between microglia and neurons.

Circulating Exosomes Derived-miR-146a from Systemic Lupus Erythematosus Patients Regulates Senescence of Mesenchymal Stem Cells.

The senescence of mesenchymal stem cells (MSCs) plays a crucial role in the development and progression of systemic lupus erythematosus (SLE). Exosomes, small spherical bilayer proteolipid vesicles, contribute to the communication between various cells and their microenvironment by transferring information via their cargo, including the proteins, lipids, and RNAs. While exosomal miRNAs participate in various biological activities, correlations of circulating exosomes with senescent signs of BM-MSCs remain unclear. In our study, we aimed at exploring the roles of circulating exosomal miRNAs in the senescence of MSCs. We found that exosomes derived from SLE serum could increase the proportions of SA-ß-gal positive cells, disorganize cytoskeletons, and reduce growth rates. Moreover, the expression of miR-146a declined significantly in serum exosomes of SLE patients compared with healthy controls. miR-146a could be internalized into MSCs via exosomes and participate in MSCs senescence through targeting TRAF6/NF-κB signaling. These results clarified the novel mechanism of MSCs senescence in SLE patients.

Targeting HMGB1 by ethyl pyruvate ameliorates systemic lupus erythematosus and reverses the senescent phenotype of bone marrow-mesenchymal stem cells.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs and systems. Mesenchymal stem cells (MSCs) from SLE patients have demonstrated defects such as impaired growth, senescence phenotype and immunomodulatory functions. Some studies have suggested the close connection between inflammation microenvironment and cellular senescence. In the current study, we detected cytokines levels in bone marrow supernatant by the quantitative proteomics analysis, and found the expression of HMGB1 was remarkably increased in bone marrow from SLE patients. Senescence associated-ß-galactosidase (SA-ß-gal) staining, F-actin staining and flow cytometry were used to detect the senescence of cells. After stimulation of HMGB1 in normal MSCs, the ratio of SA-ß-gal positive in BM-MSCs was increased, the organization of cytoskeleton was disordered, and TLR4-NF-κB signaling was activated. Finally, Ethyl pyruvate (EP) (40 mg/kg and 100 mg/kg, three times a week), a high security HMGB1 inhibitor, was injected intraperitoneally to treat MRL/lpr mice for 8 weeks. We demonstrated that EP alleviated the clinical aspects of lupus nephritis and prolonged survival of MRL/lpr mice. In the meantime, EP reversed the senescent phenotype of BM-MSCs from MRL/lpr mice. HMGB1 could be a promising target in SLE patients, and might be one of the reasons of recurrence after MSCs transplantation.

Langer's axillary arch lymph node metastasis in breast cancer patients: A prospective clinical study.

BACKGROUND AND OBJECTIVES: Latissimus dorsi, an anatomical landmark for axillary lymph node dissection, was reported to harbor an anatomical variation named Langer's axillary arch (LAA). However, the incidence and clinical significance of LAA in breast cancer remain obscure. METHODS: We conducted a six-year prospective study, including 1724 breast cancer patients in Qilu hospital between January 2012 to February 2018. All patients received ALND were inspected for existence of LAA. All the surgeries were completed with the involvement of same experienced surgeon. Once the LAA was identified, all the lymph nodes located lateral to it, named LAA's lymph node, were dissected and collected for pathologic examination. RESULTS: Among 1724 breast cancer patients, LAA was identified in 132 patients (7.66%). 120 out of the 132 patients (90.91%) had at least two LAA's lymph nodes. 21 out of 120 patients (17.50%) were confirmed with cancer cell metastasis in LAA's lymph nodes. Among the 23 patients received sentinel lymph node tracing, sentinel lymph node was located lateral to LAA in 3 patients (13.04%). CONCLUSIONS: Our results indicated that it is of great importance for surgeons to correctly ascertain LAA, and it should be taken as a nonnegligible parts during ALND or SLNB.

Relationship between Upper Extremity Lymphatic Drainage and Sentinel Lymph Nodes in Patients with Breast Cancer.

PURPOSE: The purpose of this study was to identify the relationship between upper extremity lymphatics and sentinel lymph nodes (SLNs) in breast cancer patients. METHODS: Forty-four patients who underwent axillary reverse mapping (ARM) during axillary lymph node dissection (ALND) with SNL biopsy (SLNB) between February 2017 and October 2017 were investigated. ARM was performed using indocyanine green (ICG) to locate the upper extremity lymphatics; methylene blue dye was injected intradermally for SLN mapping. RESULTS: ARM nodes were found in the ALND fields of all examined patients. The rate of identification of upper extremity lymphatics within the SLNB field was 65.9% (29 of 44). The ARM nodes were involved in metastases arising from primary breast tumors in 7 of the patients (15.9%), while no metastases were detected in pathologic axillary lymph node-negative patients. Lymphatics from the upper extremity drained into the SLNs in 5 of the 44 patients (11.4%); their ARM-detected nodes were found to be in close proximity to the SLNs. CONCLUSIONS: The ARM nodes and SLNs are closely related and share lymphatic drainage routes. The ARM procedure using fluorescence imaging is both feasible and, in patients who are SLN negative, oncologically safe. ARM using ICG is therefore effective for identifying and preserving upper extremity lymphatics, and SLNB combined with ARM appears to be a promising surgical refinement for preventing upper extremity lymphoedema. CLINICAL TRIAL REGISTRATION: This trial is registered with ClinicalTrial.gov: NCT02651142.

Correction: Trail Resistance Induces Epithelial-Mesenchymal Transition and Enhances Invasiveness by Suppressing PTEN via miR-221 in Breast Cancer.

[This corrects the article DOI: 10.1371/journal.pone.0099067.].

PKM2 Involved in Neuronal Apoptosis on Hypoxic-ischemic Encephalopathy in Neonatal Rats.

Pyruvate Kinase isozymes M2 (PKM2) is a glycolytic enzyme involved in glycolysis that decarboxylates phosphoenolpyruvate to pyruvate and generates ATP. PKM2 also plays a significant role in tumor growth, in cell division, angiogenesis, apoptosis and metastasis. In this study, we have investigated the role of PKM2 in cortical neurons which suffered hypoxic-ischemic encephalopathy (HIE) in newborn rats. Immunohistochemistry and Western blot analysis revealed the protein expression of PKM2 peaking at 24 h after HIE. Double immunofluorescence labeling showed that PKM2 was mainly located in the neurons of the ipsilateral cerebral cortex, not in astrocytes or microglia. The increased level of active caspase-3 and the decreased level of phosphorylated AKT (p-AKT) were consistent with the PKM2 expression. TUNEL staining assay showed that PKM2 may participate in neuronal apoptosis in the rat ipsilateral cerebral cortex. Silencing of PKM2 in primary cultures of cortical neurons using a specific siRNA reduced the expression of active caspase-3 and upregulated p-AKT expression. Taken together, the results indicate that PKM2 may be involved in neuronal apoptosis after HIE by a mechanism dependent on the inactivation of p-AKT.

LncRNA-CDC6 promotes breast cancer progression and function as ceRNA to target CDC6 by sponging microRNA-215.

Rapid proliferation and metastasis of breast cancers resulted in poor prognosis in clinic. Recent studies have proved that long noncoding RNAs (lncRNAs) were involved in tumor progression. In this study, we aimed to determine the roles and mechanisms of lncRNA-cell division cycle 6 (CDC6) in regulating proliferation and metastasis of breast cancer. Clinically, lncRNA-CDC6 was highly expressed in tumor tissues and was positively correlated with clinical stages of breast cancers. Functionally, the ectopic expression of lncRNA-CDC6 promoted proliferation via regulation of G1 phase checkpoint, and further promoting the migration capability. Moreover, lncRNA-CDC6 could function as competitive endogenous RNA (ceRNA) via directly sponging of microRNA-215 (miR-215), which further regulating the expression of CDC6. Taken together, our results proved that lncRNA-CDC6 could function as ceRNA and promote the proliferation and metastasis of breast cancer cells, which provided a novel prognostic marker for breast cancers in clinic.

TNF-α regulates microglial activation via the NF-κB signaling pathway in systemic lupus erythematosus with depression.

This study aimed to investigate the effects of tumor necrosis factor-α (TNF-α) on systemic lupus erythematosus (SLE). The animal model of MRL/MpJ-Faslpr mice (MRL/lpr; lupus-prone mice) showed depression-like behaviors based on tail suspension, sucrose preference, and open field tests. Brain microglia were significantly activated with obvious increases in proinflammatory cytokines. In addition, in vitro experiments showed that TNF-α activated microglia by upregulating the NF-κB signaling pathway and proinflammatory cytokines. PDTC, a specific NF-κB inhibitor, effectively reduced TNF-α-mediated inflammatory signaling in microglia. These results suggest that TNF-α-induced microglial activation has a major role in neuroinflammation of SLE with depression.