Tumor suppressor FRMD3 controls mammary epithelial cell fate determination via notch signaling pathway.

The luminal-to-basal transition in mammary epithelial cells (MECs) is accompanied by changes in epithelial cell lineage plasticity; however, the underlying mechanism remains elusive. Here, we report that deficiency of Frmd3 inhibits mammary gland lineage development and induces stemness of MECs, subsequently leading to the occurrence of triple-negative breast cancer. Loss of Frmd3 in PyMT mice results in a luminal-to-basal transition phenotype. Single-cell RNA sequencing of MECs indicated that knockout of Frmd3 inhibits the Notch signaling pathway. Mechanistically, FERM domain-containing protein 3 (FRMD3) promotes the degradation of Disheveled-2 by disrupting its interaction with deubiquitinase USP9x. FRMD3 also interrupts the interaction of Disheveled-2 with CK1, FOXK1/2, and NICD and decreases Disheveled-2 phosphorylation and nuclear localization, thereby impairing Notch-dependent luminal epithelial lineage plasticity in MECs. A low level of FRMD3 predicts poor outcomes for breast cancer patients. Together, we demonstrated that FRMD3 is a tumor suppressor that functions as an endogenous activator of the Notch signaling pathway, facilitating the basal-to-luminal transformation in MECs.

Efficacy and safety of first-line treatment for metastatic triple-negative breast cancer: A network meta-analysis.

Background: Metastatic triple-negative breast cancer (mTNBC) is an aggressive histological subtype with poor prognosis. Several first-line treatments are currently available for mTNBC. This study conducted a network meta-analysis to compare these first-line regimens and to determine the regimen with the best efficacy. Methods: A systematic search of PubMed, EMBASE, the Cochrane Central Register of Controlled Bases, and minutes of major conferences was performed. Progression-free survival (PFS), overall survival (OS), and objective response rate (ORR) were analyzed via network meta-analysis using the R software (R Core Team, Vienna, Austria). The efficacy of the treatment regimens was compared using hazard ratios and 95% confidence intervals. Results: A total of 29 randomized controlled trials involving 4607 patients were analyzed. The ranking was based on the surface under the cumulative ranking curve. Network meta-analysis results showed that cisplatin combined with nab-paclitaxel or paclitaxel was superior to docetaxel plus capecitabine in terms of PFS and ORR. For programmed death-ligand 1 (PD-L1) and breast cancer susceptibility gene (BRCA) mutation-positive tumors, atezolizumab/pembrolizumab combined with nab-paclitaxel and talazoparib was superior to docetaxel plus capecitabine. No significant difference was observed among the treatments in OS. Neutropenia, diarrhea, and fatigue were common serious adverse events. Conclusion: Cisplatin combined with nab-paclitaxel or paclitaxel is the preferred first-line treatment for mTNBC. For PD-L1 and BRCA mutation-positive tumors, atezolizumab/pembrolizumab combined with nab-paclitaxel and talazoparib is an effective treatment option. Neutropenia, diarrhea, and fatigue are frequently occurring serious adverse events.

Single axonal characterization of trigeminocerebellar projection patterns in the mouse.

The cerebellar projection from the trigeminal nuclear complex is one of the major populations of the cerebellar inputs. Although this projection is essential in cerebellar functional processing and organization, its morphological organization has not been systematically clarified. The present study addressed this issue by lobule-specific retrograde neuronal labeling and single axonal reconstruction with anterograde labeling. The cerebellar projection arose mainly from the interpolaris subdivision of the spinal trigeminal nucleus (Sp5I) and the principal trigeminal sensory nucleus (Pr5). Although crus II, paramedian lobule, lobule IX, and simple lobule were the major targets, paraflocculus, and other lobules received some projections. Reconstructed single trigeminocerebellar axons showed 77.8 mossy fiber terminals on average often in multiple lobules but no nuclear collaterals. More terminals were located in zebrin-negative or lightly-positive compartments than in zebrin-positive compartments. While Pr5 axons predominantly projected to ipsilateral crus II, Sp5I axons projected either predominantly to crus II and paramedian lobule often bilaterally, or predominantly to lobule IX always ipsilaterally. Lobule IX-predominant-type Sp5I neurons specifically expressed Gpr26. Gpr26-tagged neuronal labeling produced a peculiar mossy fiber distribution, which was dense in the dorsolateral lobule IX and extending transversely to the dorsal median apex in lobule IX. The projection to the cerebellar nuclei was observed in collaterals of ascending Sp5I axons that project to the diencephalon. In sum, multiple populations of trigeminocerebellar projections showed divergent projections to cerebellar lobules. The projection was generally complementary with the pontine projection and partly matched with the reported orofacial receptive field arrangement.

Third-line Treatment for Metastatic Triple-negative Breast Cancer: A Systematic Review and Network Meta-analysis.

OBJECTIVE: Metastatic triple-negative breast cancer (mTNBC) is an invasive histologic subtype with a poor prognosis and rapid progression. Currently, there is no standard therapy for the third-line treatment of mTNBC. In this study, we conducted a network meta-analysis to compare regimens and determine treatment outcomes. METHODS: We performed a systematic search of PubMed, EMBASE, the Cochrane Central Register of Controlled Bases, and the minutes of major conferences. Progression-free survival, overall survival, and objective response rate were analyzed through network meta-analysis using the R software (R Core Team). The efficacy of the treatment regimens was compared using hazard ratios, odds ratios, and 95% CIs. RESULTS: We evaluated 15 randomized controlled trials involving 6,010 patients. Compared with the physician's choice treatment, sacituzumab govitecan showed significant advantages in progression-free survival and overall survival, with hazard ratio values of 0.41 (95% CI: 0.32-0.52) and 0.48 (95% CI, 0.39-0.60). In terms of objective response rate, sacituzumab govitecan is the best-performing therapy (odds ratio: 10.82; 95% CI: 5.58-20.97). Adverse events among grades 3 to 5 adverse reactions, the incidence of neutropenia and leukopenia in each regimen was higher, whereas the incidence of fever, headache, hypertension, and rash was lower. CONCLUSION: Compared with the treatment of the physician's choice, sacituzumab govitecan appears more efficacious and is the preferred third-line treatment for mTNBC.

FRMD8 targets both CDK4 activation and RB degradation to suppress colon cancer growth.

Cyclin-dependent kinase 4 (CDK4) and retinoblastoma protein (RB) are both important cell-cycle regulators that function in different scenarios. Here, we report that FERM domain-containing 8 (FRMD8) inhibits CDK4 activation and stabilizes RB, thereby causing cell-cycle arrest and inhibiting colorectal cancer (CRC) cell growth. FRMD8 interacts separately with CDK7 and CDK4, and it disrupts the interaction of CDK7 with CDK4, subsequently inhibiting CDK4 activation. FRMD8 competes with MDM2 to bind RB and attenuates MDM2-mediated RB degradation. Frmd8 deficiency in mice accelerates azoxymethane/dextran-sodium-sulfate-induced colorectal adenoma formation. The FRMD8 promoter is hypermethylated, and low expression of FRMD8 predicts poor prognosis in CRC patients. Further, we identify an LKCHE-containing FRMD8 peptide that blocks MDM2 binding to RB and stabilizes RB. Combined application of the CDK4 inhibitor and FRMD8 peptide leads to marked suppression of CRC cell growth. Therefore, using an LKCHE-containing peptide to interfere with the MDM2-RB interaction may have therapeutic value in CDK4/6 inhibitor-resistant patients.

FERM domain-containing protein FRMD6 activates the mTOR signaling pathway and promotes lung cancer progression.

FRMD6, a member of the 4.1 ezrin-radixin-moesin domain-containing protein family, has been reported to inhibit tumor progression in multiple cancers. Here, we demonstrate the involvement of FRMD6 in lung cancer progression. We find that FRMD6 is overexpressed in lung cancer tissues relative to in normal lung tissues. In addition, the enhanced expression of FRMD6 is associated with poor outcomes in patients with lung squamous cell carcinoma (n = 75, P = 0.0054) and lung adenocarcinoma (n = 94, P = 0.0330). Cell migration and proliferation in vitro and tumor formation in vivo are promoted by FRMD6 but are suppressed by the depletion of FRMD6. Mechanistically, FRMD6 interacts and colocalizes with mTOR and S6K, which are the key molecules of the mTOR signaling pathway. FRMD6 markedly enhances the interaction between mTOR and S6K, subsequently increasing the levels of endogenous pS6K and downstream pS6 in lung cancer cells. Furthermore, knocking out FRMD6 inhibits the activation of the mTOR signaling pathway in Frmd6-/- gene KO MEFs and mice. Altogether, our results show that FRMD6 contributes to lung cancer progression by activating the mTOR signaling pathway.

Second-line Endocrine Therapy of Hormone Receptor-positive/HER2- negative Advanced Breast Cancer: A Systematic Review and Network Meta-analysis.

BACKGROUND: The optimal second-line therapy for hormone receptor-positive (HR+)/ human epidermal growth factor receptor 2 negative (HER2-) advanced or metastatic breast cancer is yet to be established. Therefore, we conducted a network meta-analysis (NMA) of marketed drugs to compare their efficacy. METHODS: We searched the literature in PubMed, Embase, Web of Science databases, and the main international conferences in the past 5 years to find phase III clinical trials on drugs available in the market. Network meta-analysis of progression-free survival (PFS), overall survival (OS), and the objective response rate (ORR) was performed using R software. The efficiency of treatment options was compared using hazard ratios and 95% credibility intervals. RESULTS: Overall, 12 studies with 6120 patients were included in the analysis. In an indirect comparison of the five regimens, cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) plus 500 mg fulvestrant (Ful500) gave the best PFS results; palbociclib ranked first with a surface under the cumulative ranking (SUCRA) of 94.99%, followed by mammalian target of rapamycin inhibitor (mTORi) plus everolimus (SUCRA=73.07%), phosphoinositide 3-kinase inhibitor (PI3Ki) plus Ful500 (SUCRA=66.73%), Ful500 alone (SUCRA=44.55%), and histone deacetylase inhibitor (HDACi) plus exemestane (SUCRA= 43.49%). However, no significant difference was found in the PFS rates of CDK4/6i, mTORi, and PI3Ki. For OS, CDK4/6i plus Ful500 ranked first; the SUCRA of ribociclib, abemaciclib, and palbociclib were 86.20%, 83.98%, and 78.52%, respectively. Alpelisib plus Ful500 (SUCRA=66.91%) ranked second but was not statistically different from CDK4/6i. The mTORi plus everolimus group had the best ORR (SUCRA=88.73%). In terms of safety, 81.56% of patients in the tucidinostat plus exemestane regimen developed neutropenia, suggesting strong hematological toxicity; 13.40% of patients developed grade 3-4 diarrhea after using abemaciclib plus Ful500. CONCLUSION: For second-line endocrine therapy in HR+/HER2- advanced/metastatic breast cancer, CDK4/6i is a better choice than mTORi, PI3Ki, HDACi, and Ful; it shows good PFS and OS outcomes and a low probability for serious adverse events.>.

Treatment options for patients with human epidermal growth factor 2-positive breast cancer brain metastases: A systematic review and meta-analysis.

Introduction: Many systemic treatment options are available for patients with human epidermal growth factor 2 (HER2)-positive breast cancer brain metastases. However, it is unclear which pharmacological treatment option is the most beneficial. Methods: We searched databases, such as PubMed, Embase, and Cochrane Library, and conference abstracts according to keywords. We extracted progression-free survival (PFS), overall survival (OS) data, and overall response rate (ORR) from randomized controlled trials and single-arm studies of HER2-positive breast cancer brain metastasis treatment for meta-analysis and analyzed different drug-related adverse events (AEs). Results: Three randomized controlled trials and seven single-arm clinical studies with 731 patients with HER2-positive brain metastases from breast cancer involving at least seven drugs were included. In randomized controlled trials, our results showed that trastuzumab deruxtecan significantly improved PFS and OS in patients and was superior to other drug regimens. In the single-arm study, the ORR was more pronounced for the trastuzumab deruxtecan and pyrotinib plus capecitabine regimens (ORR, 73.33%; 95% confidence intervals [CI], 44.90%-92.21%; ORR, 74.58%; 95% CI, 61.56%-85.02%, respectively). We found that the main AEs of antibody-drug conjugate (ADC) were nausea and fatigue, while the main AE of small-molecule tyrosine kinase inhibitor (TKI) drugs and large monoclonal antibodies was diarrhea. Conclusions: Trastuzumab deruxtecan was shown to be the most significant in improving survival in patients with HER2-positive breast cancer brain metastases in network meta-analysis, and in single-arm study, patients with HER2-positive breast cancer brain metastases treated with trastuzumab deruxtecan and pyrotinib plus capecitabine regimen had the highest ORR. The main AEs associated with ADC, large monoclonal antibodies, and TKI drugs were nausea, fatigue, and diarrhea, respectively.

A Retrospective Study of Trifluridine/Tipiracil with Fruquintinib in Patients with Chemorefractory Metastatic Colorectal Cancer.

INTRODUCTION: Trifluridine/tipiracil (TAS-102) and fruquintinib are novel antitumor agents for patients with refractory metastatic colorectal cancer (mCRC). We conducted a retrospective study to explore the clinical efficacy and drug toxicities of combination therapy with TAS-102 and fruquintinib in real-life clinical practice. METHODS: Between March 2021 and February 2023, patients at two different centers with mCRC who failed two or more lines of prior therapy and received TAS-102 in combination with fruquintinib were recruited. RESULTS: In total, 32 mCRC patients were included in the analysis. The objective response rate (ORR) and the disease control rate (DCR) were 9.4% and 75%. The median progression-free survival (PFS) and overall survival (OS) were 6.3 (95% CI: 5.3-7.3) and 13.5 (95% CI: 9.5-17.5) months, respectively. Patients without liver metastasis or peritoneal metastasis obtained better median PFS (7.1 m vs. 5.6 m, p = 0.03 and 6.3 m vs. 3.4 m, p = 0.04), and OS (15.2 m vs. 10.4 m, p = 0.01 and 13.6 m vs. 7.1 m, p = 0.03), respectively. Other clinicopathological features, including age, tumor site, KRAS status, dosage of fruquintinib, and treatment line, did not affect the clinical efficacy of TAS-102 combined with fruquintinib. The most common grade three-four toxicities were neutropenia (46.9%), anemia (21.9%), diarrhea (15.6%), nausea (12.5%), and hand-foot syndrome rash (12.5%). CONCLUSIONS: Our results suggest that TAS-102 combined with fruquintinib has promising clinical efficacy and manageable safety for refractory mCRC patients in a real-world clinical setting. Further prospective trials are warranted to confirm our results.

The AMPK-HOXB9-KRAS axis regulates lung adenocarcinoma growth in response to cellular energy alterations.

HOXB9 is an important transcription factor associated with unfavorable outcomes in patients with lung adenocarcinoma (LUAD). However, its degradation mechanism remains unclear. Here, we show that HOXB9 is a substrate of AMP kinase alpha (AMPKα). AMPK mediates HOXB9 T133 phosphorylation and downregulates the level of HOXB9 in mice and LUAD cells. Mechanistically, phosphorylated HOXB9 promoted E3 ligase Praja2-mediated HOXB9 degradation. Blocking HOXB9 phosphorylation by depleting AMPKα1/2 or employing the HOXB9 T133A mutant promoted tumor cell growth in cell culture and mouse xenografts via upregulation of HOXB9 and KRAS that is herein identified as a target of HOXB9. Clinically, AMPK activation levels in LUAD samples were positively correlated with pHOXB9 levels; higher pHOXB9 levels were associated with better survival of patients with LUAD. We thus present a HOXB9 degradation mechanism and demonstrate an AMPK-HOXB9-KRAS axis linking glucose-level-regulated AMPK activation to HOXB9 stability and KRAS gene expression, ultimately controlling LUAD progression.

Heterogeneity of intrinsic plasticity in cerebellar Purkinje cells linked with cortical molecular zones.

In the cerebellar cortex, heterogeneous populations of Purkinje cells (PCs), classified into zebrin (aldolase C)-positive (Z+) and -negative (Z-) types, are arranged into separate longitudinal zones. They have different topographic neuronal connections and show different patterns of activity in behavior tasks. However, whether the zebrin type of PCs directly links with the physiological properties of the PC has not been well clarified. Therefore, we applied in vitro whole-cell patch-clamp recording in Z+ and Z- PCs in vermal and hemispheric neighboring zebrin zones in zebrin-visualized mice. Intrinsic excitability is significantly higher in Z- PCs than in Z+ PCs. Furthermore, intrinsic plasticity and synaptic long-term potentiation are enhanced more in Z- PCs than in Z+ PCs. The difference was mediated by different modulation of SK channel activities between Z+ and Z- PCs. The results indicate that cellular physiology differentially tunes to the functional compartmentalization of heterogeneous PCs.

Kindlin-2 in Sertoli cells is essential for testis development and male fertility in mice.

Kindlin-2 is known to play important roles in the development of mesoderm-derived tissues including myocardium, smooth muscle, cartilage and blood vessels. However, nothing is known for the role of Kindlin-2 in mesoderm-derived reproductive organs. Here, we report that loss of Kindlin-2 in Sertoli cells caused severe testis hypoplasia, abnormal germ cell development and complete infertility in male mice. Functionally, loss of Kindlin-2 inhibits proliferation, increases apoptosis, impairs phagocytosis in Sertoli cells and destroyed the integration of blood-testis barrier structure in testes. Mechanistically, Kindlin-2 interacts with LATS1 and YAP, the key components of Hippo pathway. Kindlin-2 impedes LATS1 interaction with YAP, and depletion of Kindlin-2 enhances LATS1 interaction with YAP, increases YAP phosphorylation and decreases its nuclear translocation. For clinical relevance, lower Kindlin-2 expression and decreased nucleus localization of YAP was found in SCOS patients. Collectively, we demonstrated that Kindlin-2 in Sertoli cells is essential for sperm development and male reproduction.

Kindlin-2 Inhibits the Hippo Signaling Pathway by Promoting Degradation of MOB1.

The Hippo signaling pathway plays a key role in development and cancer progression. However, molecules that intrinsically inhibit this pathway are less well known. Here, we report that the focal adhesion molecule Kindlin-2 inhibits Hippo signaling by interacting with and degrading MOB1 and promoting the interaction between MOB1 and the E3 ligase praja2. Kindlin-2 thus inhibits the phosphorylation of LATS1 and YAP and promotes YAP translocation into the nucleus, where it activates downstream Hippo target gene transcription. Kindlin-2 depletion activates Hippo/YAP signaling and alleviates renal fibrosis in Kindlin-2 knockout mice with unilateral ureteral occlusion (UUO). Moreover, Kindlin-2 levels are negatively correlated with MOB1 and phosphorylated (p) YAP in samples from patients with renal fibrosis. Altogether, these results demonstrate that Kindlin-2 inhibits Hippo signaling through degradation of MOB1. A specific long-lasting siRNA against Kindlin-2 effectively alleviated UUO-induced renal fibrosis and could be a potential therapy for renal fibrosis.

C1orf106, an innate immunity activator, is amplified in breast cancer and is required for basal-like/luminal progenitor fate decision.

Basal-like breast cancer with a luminal progenitor gene expression profile is an aggressive subtype of breast cancer with a poorer prognosis compared with other subtypes. However, genes that specifically promote basal-like breast cancer development remain largely unknown. Here, we report that a novel gene C1orf106 plays an important role in maintaining the feature of basal-like/luminal progenitors. C1orf106 is frequently amplified and overexpressed in basal-like breast cancer and is associated with a poor outcome in patients. In human TCGA database, C1orf106 expression was correlated with upregulation of ELF5 and downregulation of GATA3, two transcription factors that regulate mammary gland stem cell fate. Enhanced expression of C1orf106 promotes tumor progression and expression of basal-like/luminal progenitor marker ELF5; depletion of C1orf106 suppresses tumorigenesis and expression of basal-like/luminal progenitor marker GATA3. These findings suggest that C1orf106 maintains the basal-like/luminal progenitor character through balancing the expression of ELF5 and GATA3. Taken together, we demonstrated that C1orf106 is an important regulator for basal-like/luminal progenitors and targeting C1orf106 is of therapeutic value for breast cancer.

Histone H1 acetylation at lysine 85 regulates chromatin condensation and genome stability upon DNA damage.

Linker histone H1 has a key role in maintaining higher order chromatin structure and genome stability, but how H1 functions in these processes is elusive. Here, we report that acetylation of lysine 85 (K85) within the H1 globular domain is a critical post-translational modification that regulates chromatin organization. H1K85 is dynamically acetylated by the acetyltransferase PCAF in response to DNA damage, and this effect is counterbalanced by the histone deacetylase HDAC1. Notably, an acetylation-mimic mutation of H1K85 (H1K85Q) alters H1 binding to the nucleosome and leads to condensed chromatin as a result of increased H1 binding to core histones. In addition, H1K85 acetylation promotes heterochromatin protein 1 (HP1) recruitment to facilitate chromatin compaction. Consequently, H1K85 mutation leads to genomic instability and decreased cell survival upon DNA damage. Together, our data suggest a novel model whereby H1K85 acetylation regulates chromatin structure and preserves chromosome integrity upon DNA damage.

HOXB9 acetylation at K27 is responsible for its suppression of colon cancer progression.

We previously reported that HOXB9 is overexpressed in colon cancer and predicts a favourable patient outcome, which is opposite to the tumour-promoting role of HOXB9 in other cancers. We hypothesized that HOXB9 acetylation may account for its inhibitory role in colon cancer. We aim to examine the role of acetylated HOXB9 in colon cancer cells and patients. The AcK27-HOXB9 levels in colon cancer cells and patients were analysed by Western blot analysis and immunohistochemistry separately. Correlation between AcK27-HOXB9 expression and patient survival was assessed by Kaplan-Meier analysis. HOXB9 target gene EZH2 was determined by luciferase assay in HOXB9-transfected colon cancer cells. Nucleocytoplasmic translocation of HOXB9 was detected by subcellular fractionation and immunofluorescence. The AcK27-HOXB9 level was decreased in colon cancer patients and predicted better outcome. HOXB9 upregulated oncogenic EZH2 expression, whereas AcK27-HOXB9 suppressed it by translocating HOXB9 from nuclei into cytoplasm. We demonstrated that AcK27-HOXB9 inhibits while non-acetylated HOXB9 promotes EZH2 expression and colon cancer progression. Thus, AcK27-HOXB9 underlies the tumour suppressive role of HOXB9. Detection of the ratio between AcK27-HOXB9 and HOXB9 is of differential diagnostic value for colon cancer patients.