Substrates mimicking the blastocyst geometry revert pluripotent stem cell to naivety.

Naive pluripotent stem cells have the highest developmental potential but their in vivo existence in the blastocyst is transient. Here we report a blastocyst motif substrate for the in vitro reversion of mouse and human pluripotent stem cells to a naive state. The substrate features randomly varied microstructures, which we call motifs, mimicking the geometry of the blastocyst. Motifs representing mouse-blastocyst-scaled curvature ranging between 15 and 62 mm-1 were the most efficient in promoting reversion to naivety, as determined by time-resolved correlative analysis. In these substrates, apical constriction enhances E-cadherin/RAC1 signalling and activates the mechanosensitive nuclear transducer YAP, promoting the histone modification of pluripotency genes. This results in enhanced levels of pluripotency transcription factor NANOG, which persist even after cells are removed from the substrate. Pluripotent stem cells cultured in blastocyst motif substrates display a higher development potential in generating embryoid bodies and teratomas. These findings shed light on naivety-promoting substrate design and their large-scale implementation.

lncRNA-WAL promotes triple-negative breast cancer aggression by inducing ß-catenin nuclear translocation.

Because of its insensitivity to existing radiotherapy, namely chemotherapy and targeted treatments, triple-negative breast cancer (TNBC) remains a great challenge to overcome. Increasing evidence has indicated abnormal Wnt/ß-catenin pathway activation in TNBC but not luminal or HER2+ breast cancer, and lncRNAs play a key role in a variety of cancers. Through lncRNA microarray profiling between activated and inactivated wnt/ß-catenin pathway of TNBC tissues, lnc-WAL (wnt/ß-catenin associated lncRNA; WAL) was selected as the top upregulated lncRNA in wnt/ß-catenin pathway activation compared with the inactivation group. RIP-seq was used to compare the ß-catenin and IgG groups, where lnc-WAL could interact with ß-catenin. Clinically, increased lnc-WAL in TNBC tumor tissue was associated with shorter survival. lnc-WAL promoted EMT, the proliferation, migration and invasion of breast cancer stem cells (BCSCs), and TNBC cells. Mechanistically, lnc-WAL inhibited ß-catenin protein degradation via Axin-mediated phosphorylation at serine 45. Subsequently, ß-catenin accumulated in the nucleus and activated the target genes. Importantly, wnt/ß-catenin pathway activation stimulated the transcription of lnc-WAL. These results pointed to a master regulatory role of lnc-WAL/Axin/ß-catenin in the malignant progression of TNBC. Our findings provide important clinical translational evidence that lnc-WAL may be a potential therapeutic target against TNBC. Implications: The positive feedback between lnc-WAL and the Wnt/ß-catenin pathway promotes TNBC progression, and lnc-WAL could be a potential prognostic marker for TNBC patients.

LncRNA ZFPM2-AS1 promotes phyllodes tumor progression by binding to CDC42 and inhibiting STAT1 activation.

Breast phyllodes tumor (PT) is a rare fibroepithelial neoplasm with potential malignant behavior. Long non-coding RNAs (lncRNAs) play multifaceted roles in various cancers, but their involvement in breast PT remains largely unexplored. In this study, microarray was leveraged for the first time to investigate the role of lncRNA in PT. We identified lncRNA ZFPM2-AS1 was significantly upregulated in malignant PT, and its overexpression endowed PT with high tumor grade and adverse prognosis. Furthermore, we elucidated that ZFPM2-AS1 promotes the proliferation, migration, and invasion of malignant PT in vitro. Targeting ZFPM2-AS1 through nanomaterial-mediated siRNA delivery in patient-derived xenograft (PDX) model could effectively inhibit tumor progression in vivo. Mechanistically, our findings showed that ZFPM2-AS1 is competitively bound to CDC42, inhibiting ACK1 and STAT1 activation, thereby launching the transcription of TNFRSF19. In conclusion, our study provides evidence that ZFPM2-AS1 plays a pivotal role in the pathogenesis of breast PT, and suggests that ZFPM2-AS1 could serve as a prognostic indicator for patients with PT as well as a promising novel therapeutic target.

The Impact of Adjuvant Chemotherapy on the Long-Term Prognosis of Breast Malignant Phyllodes Tumors: A Propensity Score-Matched Study.

BACKGROUND: Malignant phyllodes tumors (MPTs) are rare breast tumors with high risks of local recurrence and distant metastasis. Surgical intervention is the primary treatment, but the effectiveness of adjuvant therapies is uncertain. This study was designed to analyze the prognostic risk factors associated with MPTs and evaluate the efficacy of postoperative adjuvant chemotherapy. PATIENTS AND METHODS: Patients who were first diagnosed with MPT without distant metastasis and received R0 resection surgery between 1999 and 2023 were included in the present study and stratified into 2 groups: chemotherapy and nonchemotherapy groups. Propensity score matching (PSM) was used to balance baseline characteristics between groups. Kaplan-Meier curves were used to estimate local recurrence-free survival (LRFS) and overall survival (OS). Cox proportional hazards analyses (univariate and multivariate) were conducted to identify prognostic risk factors. RESULTS: We conducted a study involving 145 patients, 31 of whom underwent a total of 12 different chemotherapy regimens following initial surgical resection. Most patients received chemotherapy regimens primarily consisting of anthracyclines, including anthracycline + ifosfamide (AI) or anthracycline + cyclophosphamide/docetaxel (AC-T) regimens. After a median follow-up of 54.5 months, 37 (25.5%) patients experienced local recurrence and 24 (16.6%) experienced distant metastasis. No significant difference was detected in the rates of local recurrence or distant metastasis between the 2 groups. Axillary lymph node positivity was the only risk factor for LRFS, whereas older age, larger tumors, axillary lymph node positivity, local recurrence, and distant metastasis were significantly associated with worse OS. Chemotherapy did not emerge as a protective factor for LRFS (P=.501) or OS (P=.854). After PSM, patients in the chemotherapy group did not exhibit better 5-year LRFS (P=.934) or 5-year OS (P=.328). CONCLUSIONS: According to our retrospective evaluation, postoperative adjuvant chemotherapy was not associated with improved survival in patients with MPTs without distant metastasis.

Activation of Bivalent Gene POU4F1 Promotes and Maintains Basal-like Breast Cancer.

Basal-like breast cancer (BLBC) is the most aggressive molecular subtype of breast cancer with worse prognosis and fewer treatment options. The underlying mechanisms upon BLBC transcriptional dysregulation and its upstream transcription factors (TFs) remain unclear. Here, among the hyperactive candidate TFs of BLBC identified by bioinformatic analysis, POU4F1 is uniquely upregulated in BLBC and is associated with poor prognosis. POU4F1 is necessary for the tumor growth and malignant phenotypes of BLBC through regulating G1/S transition by direct binding at the promoter of CDK2 and CCND1. More importantly, POU4F1 maintains BLBC identity by repressing ERα expression through CDK2-mediated EZH2 phosphorylation and subsequent H3K27me3 modification in ESR1 promoter. Knocking out POU4F1 in BLBC cells reactivates functional ERα expression, rendering BLBC sensitive to tamoxifen treatment. In-depth epigenetic analysis reveals that the subtype-specific re-configuration and activation of the bivalent chromatin in the POU4F1 promoter contributes to its unique expression in BLBC, which is maintained by DNA demethylase TET1. Together, these results reveal a subtype-specific epigenetically activated TF with critical role in promoting and maintaining BLBC, suggesting that POU4F1 is a potential therapeutic target for BLBC.

Etomidate inhibits tumor growth of glioblastoma by regulating M1 macrophage polarization.

Glioblastoma (GBM) is a common primary central nervous system tumor. Although the multimodal integrated treatment for GBM has made great progress in recent years, the overall survival time of GBM is still short. Thus, novel treatments for GBM are worth further investigation and exploration. This study aimed to investigate the effects of etomidate on GBM tumor growth and the underlying mechanism. A xenograft tumor model was established and treated with etomidate to assess tumor growth. Immunohistochemistry (IHC) assay evaluated the positive rate of Ki67 cells in tumor tissues. Cell counting kit (CCK)-8 and EdU assays accessed the cell viability and proliferation. Immunofluorescence (IF) staining detected the distribution of macrophage markers in tumor tissues. The percentages of M1- and M2-like macrophages in tumor-associated macrophages (TAMs) and co-culture system (macrophages and GBM cells) were detected using flow cytometry. Macrophage polarization-related genes were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Etomidate treatment inhibited the tumor growth, and increased the CD86+ cells but decreased the CD206+ cells in TAMs. The gene expression of M1 markers was increased in TAMs of etomidate-treated mice, whereas that of M2 markers was decreased. Moreover, etomidate treatment increased the number of CD86+ M1-like macrophages co-cultured with tumor cells but decreased that of CD206+ M2-like macrophages, with the upregulation of M1 markers and downregulation of M2 markers. Etomidate inhibited GBM tumor growth by promoting M1 macrophage polarization, suggesting a new insight into the clinical treatment of GBM.

Comparison of the effect of two internal fixation methods for proximal clavicle fractures

SUMMARY OBJECTIVE To compare the effect of two internal fixation methods in the treatment of proximal clavicle fractures. METHODS Fifty patients with proximal clavicle fractures received surgical treatment. They were divided into a clavicular T-plate group and a double mini-plates group. The duration of the operation, blood loss during the operation, fracture healing time, and incision infection were evaluated between the two groups. RESULTS Operation time (t=2.063, P=0.058), intraoperative bleeding (t=1.979, P=0.062), and fracture healing time (t=1.082, P=0.066) were not statistically significant in the two groups. The patients were followed up for 12-18 months; one patient in the T-plate group had early removal of nails, but no clinical symptoms. At the 2-month follow-up, the ASES score in the double mini-plates group was significantly better than in the T-plate group (P<0.001); but at the 6-month follow-up, 1-week before removal of internal fixation and the final follow-up, the two groups had no significant differences (P>0.05). CONCLUSIONS Both internal fixations have similar clinical results in the duration of operation, blood loss during the operation, and fracture healing time. The double mini-plates fixation presents advantages by reducing complications and speeding fracture healing; thus it is a more effective method to treat proximal clavicle fractures.

RESUMO OBJETIVO Comparar o efeito de dois métodos de fixação interna no tratamento de fraturas da clavícula proximal. MÉTODOS Cinquenta pacientes com fraturas da clavícula proximal receberam tratamento cirúrgico. Eles foram divididos em um grupo de placa T clavicular e um grupo de miniplacas duplas. A duração da operação, perda de sangue durante a operação, tempo de cura da fratura e infecção na incisão foram avaliados nos dois grupos. RESULTADOS O tempo de operação (t=2,063, P=0,058), perda de sangue durante a operação (t=1,979, P=0,062) e tempo de cura das fraturas (t=1,082, P=0,066) não foram estatisticamente significativos nos dois grupos. Os pacientes foram acompanhados por 12-18 meses; um dos pacientes do grupo da placa T teve retirada antecipada dos parafusos, mas não apresentou sintomas clínicos. Aos dois meses de acompanhamento, a pontuação ASES no grupo de miniplacas duplas foi significativamente melhor do que a do grupo de placas T (P<0,001). Porém, no acompanhamento de seis meses, uma semana antes da remoção da fixação interna e do acompanhamento final, os dois grupos não apresentavem diferenças significativas (P>0,05). CONCLUSÃO Ambas técnicas de fixação interna têm resultados clínicos semelhantes quanto a duração da operação, perda de sangue durante a operação e tempo de cura da fratura. A fixação de miniplacas duplas apresenta vantagens quanto a redução das complicações e cura mais rápida da fratura, sendo, portanto, um método mais eficaz para tratar fraturas da clavícula proximal.