CDK2-activated TRIM32 phosphorylation and nuclear translocation promotes radioresistance in triple-negative breast cancer.

INTRODUCTION: Despite radiotherapy being one of the major treatments for triple-negative breast cancer (TNBC), new molecular targets for its treatment are still required due to radioresistance. CDK2 plays a critical role in TNBC. However, the mechanism by which CDK2 promotes TNBC radioresistance remains to be clearly elucidated. OBJECTIVES: We aimed to elucidate the relationship between CDK2 and TRIM32 and the regulation mechanism in TNBC. METHODS: We performed immunohistochemical staining to detect nuclear TRIM32, CDK2 and STAT3 on TNBC tissues. Western blot assays and PCR were used to detect the protein and mRNA level changes. CRISPR/Cas9 used to knock out CDK2. shRNA-knockdown and transfection assays also used to knock out target genes. GST pull-down analysis, immunoprecipitation (IP) assay and in vitro isomerization analysis also used. Tumorigenesis studies also used to verify the results in vitro. RESULTS: Herein, tripartite motif-containing protein 32 (TRIM32) is revealed as a substrate of CDK2. Radiotherapy promotes the binding of CDK2 and TRIM32, thus leading to increased CDK2-dependent phosphorylation of TRIM32 at serines 328 and 339. This causes the recruitment of PIN1, involved in cis-trans isomerization of TRIM32, resulting in importin α3 binding to TRIM32 and contributing to its nuclear translocation. Nuclear TRIM32 inhibits TC45-dephosphorylated STAT3, Leading to increased transcription of STAT3 and radioresistance in TNBC. These results were validated by clinical prognosis confirmed by the correlative expressions of the critical components of the CDK2/TRIM32/STAT3 signaling pathway. CONCLUSIONS: Our findings demonstrate that regulating the CDK2/TRIM32/STAT3 pathway is a promising strategy for reducing radioresistance in TNBC.

MicroRNA-325-3p Targets Human Epididymis Protein 4 to Relieve Right Ventricular Fibrosis in Rats with Pulmonary Arterial Hypertension.

BACKGROUND: Pulmonary arterial hypertension (PAH) usually causes right ventricular dysfunction, which is closely related to cardiac fibrosis. But cardiac fibrosis mechanism remains unclear. Our purpose was to explore microRNA-325-3p (miR-325-3p)/human epididymis protein 4's (HE4) role in the occurrence and development of right ventricular fibrosis in PAH. METHODS: The right ventricular fibrosis model of rats with PAH was constructed, and miR-325-3p was overexpressed to explore miR-325-3p's effect on myocardial fibrosis in rats with PAH. Pearson correlation coefficient examined the correlation between HE4 and miR-325-3p. We separated and identified the primary rat myocardial fibroblasts from the heart tissue. Then, the Ang II-treated myocardial fibroblast fibrosis model was constructed. miR-325-3p mimics and si-HE4 and oe-HE4 cell lines were constructed to investigate miR-325-3p and HE4 effects on myocardial cell fibrosis. Then, we added PI3K inhibitor LY294002 to study the effects of HE4 in cell fibrosis by the PI3K/AKT pathway. Starbase was used to predict miR-325-3p and HE4 binding sites. Dual-luciferase reporter assay verified whether miR-325-3p and HE4 were targeted. RESULTS: Overexpression of miR-325-3p alleviated myocardial fibrosis in rats with PAH. Pearson correlation coefficient showed that HE4 was negatively correlated with miR-325-3p expression. Starbase predicted that miR-325-3p had binding sites with HE4. Dual-luciferase reporter assay demonstrated that miR-325-3p targeted HE4. Overexpression of miR-325-3p downregulated HE4 and inhibited myocardial fibroblast fibrosis. HE4 knockdown inhibited myocardial fibroblast fibrosis. HE4 promoted myocardial fibroblast fibrosis and activated the PI3K/AKT pathway. In addition, HE4 affected myocardial fibroblast fibrosis through the PI3K/AKT pathway. CONCLUSIONS: miR-325-3p could target HE4 to relieve right ventricular fibrosis in rats with PAH. This study could provide new targets and strategies for right ventricular fibrosis in PAH.

Tripartite motif containing 24 regulates cell proliferation in colorectal cancer through YAP signaling.

The protein, tripartite motif containing 24 (TRIM24) is a member of the TRIM protein family, and acts as a critical co-regulator of multiple nuclear receptors. TRIM24 is dysregulated in many cancers, including colorectal carcinoma. However, its biological functions and molecular mechanisms with respect to colorectal carcinoma are still largely unknown. In the current study, we found that TRIM24 promotes YAP signaling for driving cell proliferation in colorectal cancer. TRIM24 was significantly upregulated in colorectal carcinoma, and its expression was negatively correlated with the survival of patients. Depletion of TRIM24 impaired the ability of the cancer cells to proliferate and form colonies. Furthermore, this study also revealed the mechanism underlying the recruitment of TRIM24 by the DANCR/KAT6A complex, which is bound to acetylated lysine 23 of histone H3 (H3K23), resulting in binding to the YAP promoter and activation of YAP transcription that ultimately enhances the proliferation of colorectal cancer cells. Our results revealed a novel mechanism involving TRIM24-YAP signaling for the regulation of colorectal cancer. We also identified TRIM24 as a potential therapeutic molecule for targeting colorectal cancer.

EFEMP1 as a Potential Biomarker for Diagnosis and Prognosis of Osteosarcoma.

Osteosarcoma (OS) is the most common primary bone malignancy. Our previous study revealed an association between the level of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) and the invasion, metastasis, and poor prognosis of OS. However, the exact correlation between the serum EFEMP1 level and OS diagnosis and progression was unclear. This study is aimed at determining the value of the serum EFEMP1 level in the diagnosis and prognosis of OS. Fifty-one consecutive OS patients were prospectively registered in this study. The serum EFEMP1 levels were measured using ELISA at diagnosis, after neoadjuvant chemotherapy, and before and after surgical treatment. Sixty-nine healthy subjects in the control group, nine patients with chondrosarcoma, and 12 patients with giant cell tumor of the bone were also enrolled in this study. Surgical orthotopic implantation was used to generate a mouse OS model, and the correlation between the circulating EFEMP1 levels and tumor progression was examined. Then, OS patients had significantly higher mean serum EFEMP1 levels (7.61 ng/ml) than the control subjects (1.47 ng/ml). The serum EFEMP1 levels were correlated with the Enneking staging system (r = 0.32, P = 0.021) and lung metastasis (r = 0.50, P < 0.001). There was also a correlation between the serum EFEMP1 level and EFEMP1 expression in the respective OS samples (r = 0.49, P < 0.001). Additionally, patients with either chondrosarcoma or giant cell tumor of the bone had significantly higher serum EFEMP1 levels than OS patients. Surgical and chemotherapeutic treatment led to an increase in the serum EFEMP1 levels. Then, the destruction of bone tissues might be one of the factors about the EFEMP1 levels. In the mouse OS model, the serum EFEMP1 level was correlated with tumor progression. Our results suggested that serum EFEMP1 levels might be used to distinguish OS patients from healthy controls and as an indicator for OS lung metastasis. Serum EFEMP1 levels could serve as a new and assisted biomarker for the auxiliary diagnosis and prognosis of OS.

The lncRNA PVT1 regulates nasopharyngeal carcinoma cell proliferation via activating the KAT2A acetyltransferase and stabilizing HIF-1α.

Long noncoding RNAs (lncRNAs) play important roles in regulating the development and progression of many cancers. However, the clinical significance of specific lncRNAs in the context of nasopharyngeal carcinoma (NPC) and the molecular mechanisms by which they regulate this form of cancer remain largely unclear. In this study we found that the lncRNA PVT1 was upregulated in NPC, and that in patients this upregulation was associated with reduced survival. RNA sequencing revealed that PVT1 was responsible for regulating NPC cell proliferation and for controlling a hypoxia-related phenotype in these cells. PVT1 knockdown reduced NPC cell proliferation, colony formation, and tumorigenesis in a subcutaneous mouse xenograft model systems. We further found that PVT1 serves as a scaffold for the chromatin modification factor KAT2A, which mediates histone 3 lysine 9 acetylation (H3K9), recruiting the nuclear receptor binding protein TIF1ß to activate NF90 transcription, thereby increasing HIF-1α stability and promoting a malignant phenotype in NPC cells. Overexpression of NF90 or HIF-1α restored the proliferation in cells that had ceased proliferating due to PVT1 or KAT2A depletion. Conversely, overexpression of active KAT2A or TIF1ß, but not of KAT2A acetyltransferase activity-deficient mutants or TIF1ß isoforms lacking H3K9ac binding sites, promoted a PVT1-mediated increase in NF90 transcription, as well as increased HIF-1α stability and cell proliferation. PVT1 knockdown enhanced the radiosensitization effect in NPC cells via inhibiting binding between H3K9ac and TIF1ß in a manner. Taken together, our results demonstrate that PVT1 serves an oncogenic role and plays an important role in radiosensitivity in malignant NPC via activating the KAT2A acetyltransferase and stabilizing HIF-1α.

Long non-coding RNA DANCR promotes colorectal tumor growth by binding to lysine acetyltransferase 6A.

Recent studies have demonstrated that long non-coding RNAs (lncRNAs) play critical roles in cancer development and progression. However, the mechanism by which lncRNAs contribute to colorectal cancer remains unclear. In this study, we identified the lncRNA, DANCR, which was upregulated in colorectal cancer. The upregulation of DANCR expression was associated with shorter patient survival time. DANCR depletion decreased cell proliferation, cell cycle progression, and tumorigenesis in a subcutaneous mouse xenograft model system. We further demonstrated that DANCR bound with lysine acetyltransferase 6A. This binding was essential for KAT6A acetyltransferase activity and thus, it influenced the expression of KAT6A target genes. Our data indicated that DANCR functions as an oncogenic lncRNA that promotes tumor development and progression. Therefore, DANCR may be a target molecule for colorectal cancer treatment.

Clinical outcomes and associated factors of radioiodine-131 treatment in differentiated thyroid cancer with cervical lymph node metastasis.

Cervical lymph node metastasis (CLNM) is common in differentiated thyroid cancer (DTC). Radioiodine-131 (131I) treatment is recommended for the removal of residual thyroid tissue following thyroidectomy. To date, the effect of 131I therapy on the outcomes of patients with DTC with CLNM is unclear. The aim of the present study was to evaluate the final outcome of patients with DTC with CLNM according to 131I administration, and to analyze the factors that may affect clinical outcomes. A total of 357 patients with DTC with CLNM were recruited and divided into three groups: Those who received 2, 3 or 4 doses of 131I therapy, respectively. Successful ablation was defined as levels of stimulated serum thyroglobulin <2 ng/ml in the absence of CLNM. The rates of successful ablation were 80.35 (229/285), 76.36 (42/55) and 70.59% (12/17) for patients who received 2, 3 and 4 doses, respectively. The patients with DTC with CLNM who were <45 years old, with tumor sizes <2 cm, solitary nodules and TNM stage I-II disease exhibited significantly higher rates of successful ablation compared with the patients who were ≥45 years old, with tumor size ≥2 cm, multiple nodules and stage III-IV disease. Multivariate analyses revealed that tumor size, number of nodules and TNM stage were independent risk factors associated with successful ablation in patients with DTC with CLNM who received 2 doses of 131I therapy. 131I administration is a useful therapy to eradicate cervical lymph node metastasis in patients with DTC, and may be preferentially indicated in patients with DTC with CLNM who are aged <45 years, with tumor sizes <2 cm, solitary nodules and lower TNM stages, in order to control and prevent recurrence and/or metastases.

Mixed epithelial and stromal tumor of kidney with renal vein extension: an unusual case report and review of literature.

Mixed epithelial and stromal tumor of kidney (MESTK) is a rare but distinct renal complex neoplasm composed of a mixture of mesenchymal and epithelial elements with characteristic ovarian-type stroma. Due to its relative rarity, little is known about the histogenesis and prognostic factors of this tumor. Although most reported cases display bland histological features and benign clinical course, a few cases of malignant MESTK have been described. We report an unusual case of MESTK in a 50-year-old female patient with renal venous involvement. Macroscopically, the tumor was solid and unencapsulated in the central region of left kidney. There was a polypoid mass with slender pedicle found to extend into the renal vein forming an intravenous tumor thrombus. Histologically, both renal and intravenous mass were composed of bland spindle-shaped cells and round dilated tubules lined by epithelium without any cytological atypia. The spindle cells were diffusely positive for smooth muscle actin and desmin, while tubules were positive for pan-cytokeratin (AE1/AE3). A diagnosis of MESTK with renal vein extension was made. The patient received no adjuvant treatment after radical nephrectomy. There was no sign of recurrence or metastasis of tumor found in a period of 16-month regular follow-up. To our knowledge, this is the first case of MESTK with renal vein extension, but lacking malignant histological appearance. Additional studies of MESTK with vein involvement will be needed to determine whether this imparts any adverse behavior, similar to other benign renal tumors with vascular involvement.

EFEMP1 inhibits migration of hepatocellular carcinoma by regulating MMP2 and MMP9 via ERK1/2 activity.

The role of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) inhibiting migration in hepatocellular carcinoma (HCC) remains unknown. Expression of EFEMP1 in HCC cell lines were quantified by western blotting and real-time PCR. The role of EFEMP1 in HCC cell migration was explored in vitro via siRNA and adding purified EFEMP1 protein. The associated molecule expression was detected by western blotting after downregulation of EFEMP1 and also tested by immunohistochemistry. Eight pairs of HCC non-HCC liver samples and 215 HCC samples were subjected to immunohistochemistry. EFEMP1 was highly expressed in 7,721 and HepG2 HCC cell lines while HuH7 HCC cell line expressed the lowest level of EFEMP1 compared with the others. Downregulating EFEMP1 by siRNA markedly increased the migration ability of HCC cells while adding purified EFEMP1 protein inhibited HCC cell migration. Downregulation of EFEMP1 increased the expression of ERK1/2, MMP2 and MMP9. Furthermore, U0126 (a highly selective and potent inhibitor of pERK1/2) could abrogate the migration ability enhanced by siRNA. Accordingly, MMP2 and MMP9 were inversely expressed with EFEMP1 expression by immunohistochemistry. EFEMP1 downregulated in HCC tissues, and lower EFEMP1 expression was significantly associated with HCC patients with ascites (P=0.050), vascular invasion (P=0.044), poorer differentiation (P=0.002) and higher clinical stage (P=0.003).

Cartilage oligomeric matrix protein enhances the vascularization of acellular nerves.

Vascularization of acellular nerves has been shown to contribute to nerve bridging. In this study, we used a 10-mm sciatic nerve defect model in rats to determine whether cartilage oligomeric matrix protein enhances the vascularization of injured acellular nerves. The rat nerve defects were treated with acellular nerve grafting (control group) alone or acellular nerve grafting combined with intraperitoneal injection of cartilage oligomeric matrix protein (experimental group). As shown through two-dimensional imaging, the vessels began to invade into the acellular nerve graft from both anastomotic ends at day 7 post-operation, and gradually covered the entire graft at day 21. The vascular density, vascular area, and the velocity of revascularization in the experimental group were all higher than those in the control group. These results indicate that cartilage oligomeric matrix protein enhances the vascularization of acellular nerves.

Positive feedback loop of hepatoma-derived growth factor and ß-catenin promotes carcinogenesis of colorectal cancer.

To clarify the role of hepatoma-derived growth factor (HDGF) and ß-catenin in carcinogenesis of colorectal cancer (CRC), our results showed that high HDGF expression was found in CRC cells and tissues and significantly related to histological differentiation (p = 0.035) and lymph node metastasis (p = 0.000). Significant positive correlation between HDGF expression and ß-catenin abnormal expression was found in CRC tissues. High HDGF and lymph node metastasis were the strong independent prognostic indicators for reduced overall survival in CRC patients. HDGF knockdown dramatically inhibited cellular proliferation, migration, invasion, and tumorigenesis, both in vitro and in vivo, but induced G1 phase arrest and apoptosis in CRC cells. HDGF knock-down dramatically suppressed ß-catenin and its down-stream genes expression in CRC cells. Intriguingly, ß-catenin knock-down dramatically suppressed HDGF expression in CRC cells. Human recombinant Wnt3a and DKK1 treatment increased and decreased HDGF, ß-catenin, c-Myc, cyclin D1, MMP9, and phos-GSK-3ß (Ser9) protein expression in nuclear and cytoplasmic fraction of CRC cells upon ß-catenin knock-down, respectively. Three HDGF-binding elements in ß-catenin promoter were found and specific for transcriptional activation of ß-catenin in CRC cells. In conclusion, our results first suggest that HDGF and ß-catenin interacts as a positive feedback loop, which plays an important role in carcinogenesis and progression of CRC.