Melatonin as an immunomodulator in CD19-targeting CAR-T cell therapy: managing cytokine release syndrome.

BACKGROUND: Chimeric antigen receptor CAR-T cell therapies have ushered in a new era of treatment for specific blood cancers, offering unparalleled efficacy in cases of treatment resistance or relapse. However, the emergence of cytokine release syndrome (CRS) as a side effect poses a challenge to the widespread application of CAR-T cell therapies. Melatonin, a natural hormone produced by the pineal gland known for its antioxidant and anti-inflammatory properties, has been explored for its potential immunomodulatory effects. Despite this, its specific role in mitigating CAR-T cell-induced CRS remains poorly understood. METHODS: In this study, our aim was to investigate the potential of melatonin as an immunomodulatory agent in the context of CD19-targeting CAR-T cell therapy and its impact on associated side effects. Using a mouse model, we evaluated the effects of melatonin on CAR-T cell-induced CRS and overall survival. Additionally, we assessed whether melatonin administration had any detrimental effects on the antitumor efficacy and persistence of CD19 CAR-T cells. RESULTS: Our findings demonstrate that melatonin effectively mitigated the severity of CAR-T cell-induced CRS in the mouse model, leading to improved overall survival outcomes. Remarkably, melatonin administration did not compromise the antitumor effectiveness or persistence of CD19 CAR-T cells, indicating its compatibility with therapeutic goals. These results suggest melatonin's potential as an immunomodulatory compound to alleviate CRS without compromising the therapeutic benefits of CAR-T cell therapy. CONCLUSION: The study's outcomes shed light on melatonin's promise as a valuable addition to the existing treatment protocols for CAR-T cell therapies. By attenuating CAR-T cell-induced CRS while preserving the therapeutic impact of CAR-T cells, melatonin offers a potential strategy for optimizing and refining the safety and efficacy profile of CAR-T cell therapy. This research contributes to the evolving understanding of how to harness immunomodulatory agents to enhance the clinical application of innovative cancer treatments.

De novo NAD+ synthesis contributes to CD8+ T cell metabolic fitness and antitumor function.

The dysfunction and clonal constriction of tumor-infiltrating CD8+ T cells are accompanied by alterations in cellular metabolism; however, how the cell-intrinsic metabolic pathway specifies intratumoral CD8+ T cell features remains elusive. Here, we show that cell-autonomous generation of nicotinamide adenine dinucleotide (NAD+) via the kynurenine pathway (KP) contributes to the maintenance of intratumoral CD8+ T cell metabolic and functional fitness. De novo NAD+ synthesis is involved in CD8+ T cell metabolism and antitumor function. KP-derived NAD+ promotes PTEN deacetylation, thereby facilitating PTEN degradation and preventing PTEN-dependent metabolic defects. Importantly, impaired cell-autonomous NAD+ synthesis limits CD8+ T cell responses in human colorectal cancer samples. Our results reveal that KP-derived NAD+ regulates the CD8+ T cell metabolic and functional state by restricting PTEN activity and suggest that modulation of de novo NAD+ synthesis could restore CD8+ T cell metabolic fitness and antitumor function.

USP47 inhibits m6A-dependent c-Myc translation to maintain regulatory T cell metabolic and functional homeostasis.

The functional integrity of Tregs is interwoven with cellular metabolism; however, the mechanisms governing Treg metabolic programs remain elusive. Here, we identified that the deubiquitinase USP47 inhibited c-Myc translation mediated by the RNA N6-methyladenosine (m6A) reader YTHDF1 to maintain Treg metabolic and functional homeostasis. USP47 positively correlated with the tumor-infiltrating Treg signature in samples from patients with colorectal cancer and gastric cancer. USP47 ablation compromised Treg homeostasis and function in vivo, resulting in the development of inflammatory disorders, and boosted antitumor immune responses. USP47 deficiency in Tregs triggered the accumulation of the c-Myc protein and in turn exacerbated hyperglycolysis. Mechanistically, USP47 prevented YTHDF1 ubiquitination to attenuate the association of YTHDF1 with translation initiation machinery, thereby decreasing m6A-based c-Myc translation efficiency. Our findings reveal that USP47 directs m6A-dependent metabolic programs to orchestrate Treg homeostasis and suggest novel approaches for selective immune modulation in cancer and autoimmune diseases by targeting of USP47.

TRAF3/STAT6 axis regulates macrophage polarization and tumor progression.

Converting tumor-associated macrophages (TAMs) from the M2 to the M1 phenotype is considered an effective strategy for cancer therapy. TRAF3 is known to regulate NF-κB signaling. However, the role of TRAF3 in TAM polarization has not yet been completely elucidated. Here, we found that ablation of TRAF3 increased M1 markers, iNOS, FGR and SLC4A7, while down-regulated M2 markers, CD206, CD36 and ABCC3, expression levels in macrophages. Moreover, TRAF3 deficiency enhanced LPS-induced M1 and abolished IL-4-induced macrophage polarization. Next, quantitative ubiquitomics assays demonstrated that among the quantitative 7618 ubiquitination modification sites on 2598 proteins, ubiquitination modification of IL-4 responding proteins was the most prominently reduced according to enrichment analysis. STAT6, a key factor of IL-4 responding protein, K450 and K129 residue ubiquitination levels were dramatically decreased in TRAF3-deficient macrophages. Ubiquitination assay and luciferase assay demonstrated that TRAF3 promotes STAT6 ubiquitination and transcriptional activity. Site mutation analysis revealed STAT6 K450 site ubiquitination played a vital role in TRAF3-mediated STAT6 activation. Finally, B16 melanoma mouse model demonstrated that myeloid TRAF3 deficiency suppressed tumor growth and lung metastasis in vivo. Taken together, TRAF3 plays a vital role in M2 polarization via regulating STAT6 K450 ubiquitination in macrophages.

Comprehensive Analysis and Experimental Validation of a Novel Estrogen/Progesterone-Related Prognostic Signature for Endometrial Cancer.

Estrogen and progesterone are the major determinants of the occurrence and development of endometrial cancer (EC), which is one of the most common gynecological cancers worldwide. Our purpose was to develop a novel estrogen/progesterone-related gene signature to better predict the prognosis of EC and help discover effective therapeutic strategies. We downloaded the clinical and RNA-seq data of 397 EC patients from The Cancer Genome Atlas (TCGA) database. The "limma" R package was used to screen for estrogen/progesterone-related differentially expressed genes (DEGs) between EC and normal tissues. Univariate and multivariate Cox proportional hazards regression analyses were applied to identify these DEGs that were associated with prognosis; then, a novel estrogen/progesterone-related prognostic signature comprising CDC25B, GNG3, ITIH3, PRXL2A and SDHB was established. The Kaplan-Meier (KM) survival analysis showed that the low-risk group identified by this signature had significantly longer overall survival (OS) than the high-risk group; the receiver operating characteristic (ROC) and risk distribution curves suggested this signature was an accurate predictor independent of risk factors. A nomogram incorporating the signature risk score and stage was constructed, and the calibration plot suggested it could accurately predict the survival rate. Compared with normal tissues, tumor tissues had increased mRNA levels of GNG3 and PRXL2A and a reduced mRNA level of ITIH3. The knockdown of PRXL2A and GNG3 significantly inhibited the proliferation and colony formation of Ishikawa and AN3CA cells, while the inhibition of PRXL2A expression suppressed xenograft growth. In this study, five estrogen/progesterone-related genes were identified and incorporated into a novel signature, which provided a new classification tool for improved risk assessment and potential molecular targets for EC therapies.

TRK-fused gene (TFG) regulates ULK1 stability via TRAF3-mediated ubiquitination and protects macrophages from LPS-induced pyroptosis.

TRK-fused gene (TFG) is known to be involved in protein secretion and plays essential roles in an antiviral innate immune response. However, its function in LPS-induced inflammation and pyroptotic cell death is still unknown. Here, we reported that TFG promotes the stabilization of Unc-51 like autophagy activating kinase (ULK1) and participates in LPS plus nigericin (Ng) induced pyroptotic cell death. Our results showed that TFG-deficient THP-1 macrophages exhibit higher mitochondrial ROS production. LPS/Ng stimulation triggers a much higher level of ROS and induces pyroptotic cell death. ULK1 undergoes a rapid turnover in TFG-deficient THP-1 cells. TFG forms complex with an E3 ligase, tumor necrosis factor receptor-associated factor 3 (TRAF3), and stabilizes ULK1 via disturbing ULK1-TRAF3 interaction. Knockdown of TFG facilitates the interaction of ULK1 with TRAF3 and subsequent K48-linked ULK1 ubiquitination and proteasome degradation. Rescue of ULK1 expression blocks LPS/Ng-induced cell death in TFG-deficient THP-1 macrophages. Taken together, TFG plays an essential role in LPS/Ng-induced pyroptotic cell death via regulating K48-linked ULK1 ubiquitination in macrophages.

Protein Tyrosine Kinase 7 Regulates EGFR/Akt Signaling Pathway and Correlates With Malignant Progression in Triple-Negative Breast Cancer.

PURPOSE: Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, is associated with high invasiveness, high metastatic occurrence and poor prognosis. Protein tyrosine kinase 7 (PTK7) plays an important role in multiple cancers. However, the role of PTK7 in TNBC has not been well addressed. This study was performed to evaluate the role of PTK7 in the progression of TNBC. METHODS: Correlation of PTK7 expression with clinicopathological parameters was assessed using tissue microarray immunohistochemistry (IHC) staining in 280 patients with breast cancer. PTK7 expression in TNBC (MDA-MB-468, MDA-MB-436 and MDA-MB-231) and non-TNBC (MCF7 and SK-BR-3) breast cancer cell lines were examined using immunoblotting assay. PTK7 correlated genes in invasive breast carcinoma were analyzed using cBioPortal breast cancer datasets including 1,904 patients. PTK7 overexpressed or knockdown TNBC cell lines (MDA-MB-468 and MDA-MB-436) were used to analyze the potential roles of PTK7 in TNBC metastasis and tumor progression. A TNBC tumor bearing mouse model was established to further analyze the role of PTK7 in TNBC tumorigenicity in vivo. RESULTS: PTK7 is highly expressed in breast cancer and correlates with worse prognosis and associates with tumor metastasis and progression in TNBC. Co-expression analysis and gain- or loss-of-function of PTK7 in TNBC cell lines revealed that PTK7 participates in EGFR/Akt signaling regulation and associated with extracellular matrix organization and migration genes in breast cancer, including COL1A1, FN1, WNT5B, MMP11, MMP14 and SDC1. Gain- or loss-of-function experiments of PTK7 suggested that PTK7 promotes proliferation and migration in TNBC cell lines. PTK7 knockdown MDA-MB-468 cell bearing mouse model further demonstrated that PTK7-deficiency inhibits TNBC tumor progression in vivo. CONCLUSION: This study identified PTK7 as a potential marker of worse prognosis in TNBC and revealed PTK7 promotes TNBC metastasis and progression via EGFR/Akt signaling pathway.

Transcriptional network constituted of CBP, Ku70, NOX2, and BAX prevents the cell death of necrosis, paraptosis, and apoptosis in human melanoma.

CREB-binding protein (CBP) is an acetyltransferase known to play multiple roles in the transcriptions of genes involving oxidative metabolism, cell cycle, DNA damage checkpoints, and cell death. In this study, CBP was found to positively regulate the expression of Ku70, and both CBP and Ku70 were found to negatively regulate the expression of NOX2, therefore, mitigating the intracellular ROS in human melanoma. Knocking down CBP or Ku70 induced necrotic and paraptotic cell death as indicated by high-level intracellular ROS, cytoplasmic vacuolization, and cell cycle arrest in the S phase. In addition, chromosomal condensations were also observed in the cells proceeding necrotic and paraptotic cell death, which was found to be related to the BAX-associated intrinsic pathway of apoptotic cell death, when Ku70 was decreased either by CBP depletion or by Ku70 depletion directly. Our results, therefore, supported the idea that CBP, Ku70, BAX, and NOX2 have formed a transcriptional network in the prevention of cell death of necrosis, paraptosis, and apoptosis in human melanoma.

SP1-induced upregulation of lncRNA CTBP1-AS2 accelerates the hepatocellular carcinoma tumorigenesis through targeting CEP55 via sponging miR-195-5p.

As reported in many research, LncRNA CTBP1 divergent transcript (CTBP1-AS2) remarkably affects the progression of several tumors. However, the precise role and function of CTBP1-AS2 in hepatocellular carcinoma (HCC) remained unknown. We found that CTBP1-AS2 expressions were increased in HCC samples and cells. After treatment with microwave ablation (MWA), CTBP1-AS2 was distinctly up-regulated in residual HCC tissues compared with HCC samples. CTBP1-AS2 was upregulated under the induction of the nuclear transcription factor SP1. As revealed by the clinical assays, high CTBP1-AS2 expression usually related to lymph node metastasis, clinical stage and weaker prognosis specific to HCC patients. Functionally, CTBP1-AS2 knockdown suppressed HCC cells in terms of the proliferation, migration, invasion, chemotherapy resistance as well as EMT progress, but promoted apoptosis. Mechanistically, CTBP1-AS2 was a sponge of miR-195-5p for elevating CEP55 expression, a target of miR-195-5p, and thereby exhibited its oncogenic roles in HCC progression. Overall, an emerging regulatory mechanism of SP1/CTBP1-AS2/miR-195-5p/CEP55 axis was reported in the paper, which possibly served as a new therapeutic HCC treatment target.

Tanshinone â ¡A inhibits VSMC inflammation and proliferation in vivo and in vitro by downregulating miR-712-5p expression.

The inflammation and proliferation of vascular smooth muscle cells (VSMCs) are the basic pathological feature of proliferative vascular diseases. Tanshinone ⅡA (Tan ⅡA), which is the most abundant fat-soluble element extracted from Salvia miltiorrhiza, has potent protective effects on the cardiovascular system. However, the underlying mechanism is still not fully understood. Here, we show that Tan ⅡA significantly inhibits neointimal formation and decreases VSMC inflammation by upregulating the expression of KLF4 and inhibiting the activation of NFκB signaling. Using a microRNA array analysis, we found that miR-712-5p expression is significantly upregulated in tumor necrosis factor alpha (TNF-α)-treated VSMCs. Loss- and gain-of-function experiments revealed that transfection of miR-712-5p mimic promotes, whereas depletion of miR-712-5p suppresses TNF-α-induced VSMC inflammation, leading to amelioration of intimal hyperplasia induced by carotid artery ligation. Moreover, depletion of miR-712-5p by its antagomir largely abrogates TNF-α-induced VSMC proliferation. Our findings suggest that miR-712-5p mediates the stimulatory effect of TNF-α on VSMC inflammation, and that Tan ⅡA inhibits VSMC inflammation and proliferation in vivo and in vitro by suppression of miR-712-5p expression. Targeting miR-712-5p may be a novel therapeutic strategy to prevent proliferative vascular diseases.

TRAF3 promotes ROS production and pyroptosis by targeting ULK1 ubiquitination in macrophages.

Disrupted mitochondrial function and reactive oxygen species (ROS) generation cause cellular damage and oxidative stress-induced macrophage inflammatory cell death. It remains unclear how mitochondrial dysfunction relates to inflammasome activation and pyroptotic cell death. In this study, we demonstrated that tumor necrosis factor receptor-associated factor 3 (TRAF3) regulates mitochondrial ROS production and promotes TLR agonist LPS plus nigericin (LPS/Ng)-induced inflammasome and pyroptosis in mouse primary macrophages and human monocyte THP-1 cells. Co-IP assays confirmed that TRAF3 forms a complex with TRAF2 and cIAP1 and mediates ubiquitin and degradation of Unc-51 like autophagy activating kinase 1 (ULK1). Moreover, knockdown of ULK1 in THP-1 cells significantly promoted LPS/Ng-induced inflammasome by activating caspase 1 and mature IL-1ß. Apoptosis inducing factor (AIF) translocation from mitochondrial to nuclear was observed in ULK1-deficient THP-1 cells under LPS/Ng stimulation, which mediates LPS/Ng-induced cell death in ULK1 deficient macrophages. In conclusion, this study identified a novel role of TRAF3 in regulation of ULK1 ubiquitination and inflammasome signaling and provided molecular mechanisms by which ubiquitination of ULK1 controls mitochondrial ROS production, inflammasome activity, and AIF-dependent pyroptosis.

Upregulation of OTUD7B (Cezanne) Promotes Tumor Progression via AKT/VEGF Pathway in Lung Squamous Carcinoma and Adenocarcinoma.

OTUD7B, a multifunctional deubiquitinylase, plays an essential role in inflammation and proliferation signals. However, its function in lung cancer remains largely unknown. The aim of this study was to evaluate the prognostic significance of OTUD7B in patients with lung adenocarcinoma and squamous carcinoma and to characterize its molecular mechanisms in lung cancer progression and metastasis. Two tissue microarrays containing 150 pairs of lung squamous carcinoma and matched adjacent non-cancer tissues, and one tissue microarray containing 75 pairs of lung adenocarcinoma and adjacent non-cancer tissues were included, and immunohistochemical staining was performed to assess the clinical relevance of OTUD7B in non-small cell lung cancer. OTUD7B is highly expressed in both lung squamous carcinoma and adenocarcinoma and correlates with a worse prognosis. MTT proliferation, colony formation, migration and invasion assays and immunoblotting assay in NCI-H358 and A549 cell lines suggested that OTUD7B enhances EGF-induced Akt signal transduction and promotes lung cancer cell proliferation and migration. Immunohistochemical staining of large-scale lung cancer subjects (171 cases) revealed positive correlation of OTUD7B and VEGF expression. ELISA and tube formation assay revealed OTUD7B promotes VEGF production and angiogenesis. NCI-H358 tumor model demonstrated OTUD7B is required for lung tumor progression by facilitating activation of Akt signaling. These findings collectively identified OTUD7B as an independent predictive factor for the prognosis of non-small cell lung cancer and revealed OTUD7B promotes lung cancer cell proliferation and metastasis via Akt/VEGF signal pathway.

Triphenylethylene-Coumarin Hybrid TCH-5c Suppresses Tumorigenic Progression in Breast Cancer Mainly Through the Inhibition of Angiogenesis.

BACKGROUND: Coumarins are a wide group of naturally occurring compounds which exhibit a wide range of biological properties such as anti-cancer activities. Here, we characterized the biological functions of three Triphenylethylene-Coumarin Hybrids (TCHs) both in cell culture and nude mouse model. METHODS: Cell proliferation assay was performed in the cell cultures of both EA.hy926 endothelial cell and breast cancer cell lines treated with different concentrations of compound TCH-10b, TCH-5a and TCH-5c. Flowcytometry assay and Western blotting were used to further investigate the effect and mechanism of TCH-5c on EA.hy926 cell proliferation and cell cycle. The effects of TCH-5c on endothelial cell migration and angiogenesis were determined using cytoskeleton staining, migration assay and tube formation assay. Inhibition of breast cancer cell line derived VEGF by TCH-5c was shown through ELISA and the use of conditioned media. SK-BR-3 xenograft mouse model was established to further study the anti-tumorigenic role of compound TCH-5c in vivo. RESULTS: We found that compound TCH-5c has inhibitory effects on both vascular endothelial cells and breast cancer cell lines. Compound TCH-5c inhibited proliferation, resulted in cell death, increased p21 protein expression to induce G0/G1 arrest and changed endothelial cell cytoskeleton organization and migration in EA.hy926 endothelial cells. Compound TCH-5c also inhibited breast cancer cell line derived VEGF secretion, decreased breast cancer cell-induced endothelial cell tube formation in vitro and suppressed SK-BR-3 breast cancer cell-initiated tumor formation in vivo. CONCLUSION: Our study demonstrates that the coumarin derivative TCH-5c exerts its anti-cancer effects by 1. inhibiting endothelial cell proliferation, migration. 2. suppressing tube formation and angiogenesis induced by breast cancer cells in vitro and in vivo. Our results have potential implications in developing new approaches against breast cancer.

Primary extra-nodal non-Hodgkin lymphoma in buttock soft tissue: A rare case report.

RATIONALE: Primary extra-nodal non-Hodgkin lymphoma (PE-NHL) arising in the region of the buttocks is rare. After reviewing the literature from the last 20 years, we found only 3 reported lymphomas originating from soft tissue of the buttocks. In our case, positron emission tomography/computed tomography (PET/CT) was performed for the first time, both before and after treatment, to determine the initial stage of PE-NHL and the curative effects of treatment. PATIENT CONCERNS: We report the case of a 71-year-old woman who was admitted to our hospital due to pain, skin redness, rising skin temperature, and swelling in the right hip. DIAGNOSES: After an initial misdiagnosis of local infection, a histological examination and PET/CT were performed which revealed evidence of non-Hodgkin marginal zone B cell lymphoma of Ann Arbor stage II. INTERVENTIONS: Following unsuccessful treatment with cephalosporin, the patient was successfully treated with rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy. OUTCOMES: Comparison of the PET/CT scans taken before and after treatment showed that the lesion size had decreased, as had the fluorodeoxyglucose (FDG) uptake seen in the subcutaneous tissue of the right buttock with standardized uptake value max (SUVmax) 11.6 versus 2.5, respectively. Subsequently, no relapse or distant metastasis has been detected. LESSONS: Young doctors should suspect PE-NHL in similar cases. PET/CT is valuable in the diagnosis and treatment of PE-NHL, as well as for accurately determining PE-NHL stage and aggressiveness.

Tumor Necrosis Factor Receptor-Associated Factor Regulation of Nuclear Factor κB and Mitogen-Activated Protein Kinase Pathways.

Tumor necrosis factor receptor (TNFR)-associated factors (TRAFs) are a family of structurally related proteins that transduces signals from members of TNFR superfamily and various other immune receptors. Major downstream signaling events mediated by the TRAF molecules include activation of the transcription factor nuclear factor κB (NF-κB) and the mitogen-activated protein kinases (MAPKs). In addition, some TRAF family members, particularly TRAF2 and TRAF3, serve as negative regulators of specific signaling pathways, such as the noncanonical NF-κB and proinflammatory toll-like receptor pathways. Thus, TRAFs possess important and complex signaling functions in the immune system and play an important role in regulating immune and inflammatory responses. This review will focus on the role of TRAF proteins in the regulation of NF-κB and MAPK signaling pathways.

Overexpression of YB1 C-terminal domain inhibits proliferation, angiogenesis and tumorigenicity in a SK-BR-3 breast cancer xenograft mouse model.

Y-box-binding protein 1 (YB1) is a multifunctional transcription factor with vital roles in proliferation, differentiation and apoptosis. In this study, we have examined the role of its C-terminal domain (YB1 CTD) in proliferation, angiogenesis and tumorigenicity in breast cancer. Breast cancer cell line SK-BR-3 was infected with GFP-tagged YB1 CTD adenovirus expression vector. An 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) proliferation assay showed that YB1 CTD decreased SK-BR-3 cell proliferation, and down-regulated cyclin B1 and up-regulated p21 levels in SK-BR-3 cells. YB1 CTD overexpression changed the cytoskeletal organization and slightly inhibited the migration of SK-BR-3 cells. YB1 CTD also inhibited secreted VEGF expression in SK-BR-3 cells, which decreased SK-BR-3-induced EA.hy926 endothelial cell angiogenesis in vitro. YB1 CTD overexpression attenuated the ability of SK-BR-3 cells to form tumours in nude mice, and decreased in vivo VEGF levels and angiogenesis in the xenografts in SK-BR-3 tumour-bearing mice. Taken together, our findings demonstrate the vital role of YB1 CTD overexpression in inhibiting proliferation, angiogenesis and tumorigenicity of breast cancer cell line SK-BR-3.

The Role of the Y Box Binding Protein 1 C-Terminal Domain in Vascular Endothelial Cell Proliferation, Apoptosis, and Angiogenesis.

Different domains of the multifunctional transcription factor Y-box binding protein 1 (YB1) regulate proliferation, differentiation, and apoptosis by transactivating or repressing the promoters of various genes. Here we report that the C-terminal domain of YB1 (YB1 CTD) is involved in endothelial cell proliferation, apoptosis, and tube formation. The oligo pull-down assays demonstrated that YB1 directly binds double-stranded GC box sequences in endothelial cells through the 125-220 amino acids. Adenovirus expression vectors harboring green fluorescent protein (GFP) or GFP-tagged YB1 CTD were constructed and used to infect EA.hy926 endothelial cells. Overexpression of the YB1 CTD significantly increased p21 expression, decreased cyclin B1 expression, and inhibited the proliferation of EA.hy926 cells. YB1 CTD overexpression also increased Bax and active caspase 3 expression, decreased Bcl-2 expression, and induced apoptosis in EA.hy926 cells. Furthermore, overexpression of the YB1 CTD significantly suppressed migration and tube formation in EA.hy926 cells. Finally, YB1 CTD decreased ERK1/2 phosphorylation in EA.hy926 cells. These findings demonstrated vital roles for YB1 in endothelial cell proliferation, apoptosis, and tube formation through transcriptional regulation of GC box-related genes.

Krüppel-like factor 4 induces apoptosis and inhibits tumorigenic progression in SK-BR-3 breast cancer cells.

Krüppel-like factor 4 (KLF4) functions as either a tumor suppressor or an oncogene in different tissues by regulating the expression of various genes. The aim of this study was to reveal the functions of KLF4 in regulating breast cancer apoptosis, proliferation, and tumorigenic progression. KLF4 expression levels in breast cancer tissues and breast cancer cell lines were found to be much lower than those in nontumorous tissues and a nontransformed mammary epithelial cell line. KLF4 was upregulated in the tumor necrosis factor-α-induced SK-BR-3 breast cancer cell apoptotic process. Overexpression of KLF4 promoted SK-BR-3 breast cancer cell apoptosis and suppressed SK-BR-3 cell tumorigenicity in vivo.

[Expression of SM22α and its relationship with lymph node metastasis in breast cancer].

OBJECTIVE: to analyze the relationship between the expression of SM22α and the lymph node (LN) metastasis of breast cancer and to investigate its molecular mechanisms. METHODS: reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect the expression of SM22α in breast cancer tissue and adjacent normal breast tissue. RT-PCR and Western blot were employed to investigate the SM22α mRNA and protein level in tissues of breast fibroadenoma, breast cancer without LN metastasis and breast cancer with LN metastasis. RT-PCR and zymography were used to detect the MMP2 and MMP9 expression and activity and TIMP1 expression level in breast fibroadenoma, breast cancer samples without LN metastasis and those with LN metastasis respectively. RESULTS: the expression level of SM22α mRNA in breast cancer was significantly lower than that in breast fibroadenoma or adjacent normal breast tissue (5.1% ± 2.4% vs 15.1% ± 5.3% vs 30.1% ± 5.1%, P < 0.01). The protein and mRNA expression level of SM22α in breast cancer samples with LN metastasis were significant lower than those of breast cancer without LN metastasis (6.2% ± 3.1% vs 10.1% ± 4.1%, P < 0.01). Both the expression and activity of MMP2 and MMP9 in breast cancer samples with LN metastasis were significant higher than those without LN metastasis (P < 0.01). A strong negative correlation was found between SM22α protein level and MMP2 activity (r = -0.848; n = 27; P < 0.01) or MMP9 activity (r = -0.916; n = 27; P < 0.01) in breast cancer tissue. CONCLUSION: a down-regulation of SM22α in breast cancer is correlated with LN metastasis. SM22α may inhibit the LN metastasis through a negative regulation of MMP2 and MMP9 in breast cancer.