Stathmin Research Articles

Silencing PCMT1 enhances the sensitivity of breast cancer cells to paclitaxel through the PI3K/Akt/STMN1 pathway.

This study aimed to investigate whether silencing Protein L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) expression can enhance the sensitivity of breast cancer cells to paclitaxel and its possible mechanism. Tumor tissues and adjacent histologically normal tissues were collected from patients with breast cancer admitted to our hospital. Human normal breast epithelial cells MCF10A, human breast cancer cells MCF-7, and paclitaxel-resistant breast cancer cells MCF-7/PR were purchased. MCF-7/PR cells were further grouped into negative control (NC) group, si-PCMT1 group (transfected with si-PCMT1), 740Y-P group (treated with 740Y-P, an activator of phosphatidylinositol 3-kinase (PI3K)/ v-Akt Murine Thymoma Viral Oncogene (AKT) signaling pathway), and si-PCMT1 + 740Y-P group (transfected with si-PCMT1 and then treated with 740Y-P). The expression level of PCMT1 in tissues and cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot analysis was used to detect the protein expression level of PCMT1 in tissues and cells as well as the protein level of p-PI3K, PI3K, p-Akt, Akt, and Stathmin1 (STMN1) in cells. 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) and colony formation assays were used to determine cell viability, scratch assay was used to assess the migration ability of cells, and Transwell assay was used to assess the invasion ability of cells. The expression of PCMT1 was remarkably up-regulated in breast cancer tissues and MCF-7/PR cells. Silencing PCMT1 expression significantly inhibited the proliferation, migration, and invasion of MCF-7/PR cells, and alleviated the resistance of cancer cells to paclitaxel. Additionally, silencing PCMT1 expression also inhibited the activation of PI3K/Akt/STMN1 pathway in MCF-7/PR cells, while activating PI3K/Akt/STMN1 pathway significantly reversed the effect of silencing PCMT1 expression on MCF-7/PR cells. PCMT1 is highly expressed in breast cancer tissues and MCF-7/PR cells, and silencing PCMT1 expression can not only inhibit the development of breast cancer but also enhance paclitaxel sensitivity. Its mechanism of action may be achieved by inhibiting PI3K/Akt/STMN1 signaling.

Interaction of Nipah Virus F and G with the Cellular Protein Cortactin Discovered by a Proximity Interactome Assay.

Nipah virus (NiV) is a highly lethal zoonotic virus with a potential large-scale outbreak, which poses a great threat to world health and security. In order to explore more potential factors associated with NiV, a proximity labeling method was applied to investigate the F, G, and host protein interactions systematically. We screened 1996 and 1524 high-confidence host proteins that interacted with the NiV fusion (F) glycoprotein and attachment (G) glycoprotein in HEK293T cells by proximity labeling technology, and 863 of them interacted with both F and G. The results of GO and KEGG enrichment analysis showed that most of these host proteins were involved in cellular processes, molecular binding, endocytosis, tight junction, and other functions. Cytoscape software (v3.9.1) was used for visual analysis, and the results showed that Cortactin (CTTN), Serpine mRNA binding protein 1 (SERBP1), and stathmin 1 (STMN1) were the top 20 proteins and interacted with F and G, and were selected for further validation. We observed colocalization of F-CTTN, F-SERBP1, F-STMN1, G-CTTN, G-SERBP1, and G-STMN1 using confocal fluorescence microscopy, and the results showed that CTTN, SERBP1, and STMN1 overlapped with NiV F and NiV G in HEK293T cells. Further studies found that CTTN can significantly inhibit the infection of the Nipah pseudovirus (NiVpv) into host cells, while SERBP1 and STMN1 had no significant effect on pseudovirus infection. In addition, CTTN can also inhibit the infection of the Hendra pseudovirus (HeVpv) in 293T cells. In summary, this study revealed that the potential host proteins interacted with NiV F and G and demonstrated that CTTN could inhibit NiVpv and HeVpv infection, providing new evidence and targets for the study of drugs against these diseases.

The knockdown of stathmin with si-RNA inhibits invasion of mesothelioma

BackgroundTo investigate the mechanism of action of stathmin1 (STMN1) in mesothelioma (MSM) and whether it has any role in its treatment. MethodsSTMN1 expression was examined using immunohistochemistry in biopsy tissues taken from MSM patients. The relationships between the levels of STMN1 expression in the pathology preparations of MSM patients, and the clinicopathological characteristics of these patients, and their survival times were investigated. Transfection of STMN1-specific siRNA into SPC212 cells was compared to negative control siRNAs. The mRNA levels of genes that may play a role in invasion, apoptosis, and autophagy were evaluated by RT-PCR. ResultsThe expression of STMN1 was shown to be high in MSM tissues (p < 0.05). It was found that the only independent predictor factor affecting the survival time of MSM patients was the disease stage (p < 0.05). STMN1 was significantly reduced after siRNA intervention (81.5%). STMN1 with specific siRNA has been shown to suppress invasion by reducing the mRNA levels of cadherin-6 (CDH6), fibroblast growth factor-8 (FGF8), hypoxia-inducible factor 1 (HIF1A), matrix metallopeptidase 1–2 (gelatinase A) (MMP1–2), and TIMP metallopeptidase inhibitor 2 (TIMP2), which are important markers for invasion. Although the expression of apoptosis and autophagy-related genes, caspase-2 (Casp2) and LC-3, was reduced by silencing STMN1 with specific siRNA in western blot analysis, this effect was not observed in PCR results. ConclusionsImmunohistochemical analysis of STMN1 may contribute to the differential diagnosis of MSM, and STMN1 may also be considered as a potential therapeutic target in the early invasive stage of MSM therapy.

Association Between High Expression of Phosphorylated-STMN1 and Mesenchymal Marker Expression and Cancer Stemness in Breast Cancer.

In patients with breast cancer, the expression of stathmin1 (STMN1) has been significantly related to a poor prognosis, cancer aggressiveness, and expression of cancer stem cell markers. The STMN1 protein is closely regulated by phosphorylation in four sites. However, few studies have investigated the relationship between the expression of phosphorylated STMN1 (pSTMN1) and clinicopathological findings, including tumor-aggressive biomarkers, in patients with breast cancer. The expression levels of four pSTMN1 (Ser16, Ser25, Ser38, and Ser63) were immunohistochemically analyzed in 213 breast cancer cases. The clinicopathological factors evaluated included epithelial-mesenchymal transition (EMT) markers and cancer stem cell markers. The cytoplasmic expression of pSTMN1 (Ser16, Ser25, Ser38, and Ser63) in normal breast tissues was low. The positive expression ratios of Ser25 (54.5%) and Ser38 (39.0%) were high compared to those of Ser16 (25.8%) and Ser63 (23.9%). The overexpression of pSTMN1 (Ser38) was associated with tumor-aggressive characteristics, such as triple-negative breast cancer (TNBC) phenotypes, high mesenchymal marker, and expression of cancer stem cell markers. STMN1 phosphorylation might be associated with clinicopathological factors, breast cancer subtypes, and expression of mesenchymal markers and breast cancer stem cell markers through the regulation of STMN1 function. Ser38 phosphorylation of STMN1 may be a novel biomarker for high-grade TNBC associated with mesenchymal marker expression and cancer stemness.

STMN1 promotes cell malignancy and bortezomib resistance of multiple myeloma cell lines via PI3K/AKT signaling

ABSTRACT Background This study investigates the biological functions of Stathmin1 (STMN1) involving drug resistance and cell proliferation in multiple myeloma (MM) and its related mechanisms. Methods Bone marrow aspirates were collected from 20 MM patients, and the bone marrow mononuclear cells (BMMCs) were separated by Ficoll-Hypaque density gradient centrifugation. Blood samples of 20 patients with monoclonal gammopathy of undetermined significance (MGUS) and 20 healthy donors were collected. Normal plasma cells sorted from the peripheral blood of MGUS patients and healthy subject as controls. Two bortezomib (BTZ)-resistant MM cell lines were established, namely NCI-H929/BTZ and KM3/BTZ cells, and then transfected with lentiviruses packaging sh-STMN1 to knock down STMN1 level in BTZ-resistant cells. Expression of STMN1 was assessed by RT-qPCR and western blotting. CCK-8 assays were performed to assess 50% growth inhibition (IC50) values. Green fluorescent protein in BTZ-resistant cells infected with lentiviruses was observed by fluorescence microscopy. Cell viability, proliferation, cell cycle, and apoptosis were evaluated through MTT assays, colony formation assays, flow cytometry analyses, and TUNEL staining. Results STMN1 was upregulated in MM cells and bone marrow aspirates of MM patients. Additionally, STMN1 depletion attenuated BTZ resistance in MM cells. Moreover, downregulation of STMN1 limited the malignant phenotypes of BTZ-resistant cells. Mechanistically, the PI3K/Akt signaling was inactivated by STMN1 downregulation in BTZ-resistant cells. Conclusion STMN1 silencing inhibits cell proliferation and BTZ resistance in MM by inactivating the PI3K/Akt signaling.

Hsa_circ_0119412 is a tumor promoter in hepatocellular carcinoma by inhibiting miR-526b-5p to upregulate STMN1

ABSTRACT Hepatocellular carcinoma (HCC) is always deemed a deadly malignancy worldwide. Non-coding RNAs, including circRNAs, are becoming more widely recognized as essential regulators of the malignant development of HCC. Thus, we elaborated the regulating role of hsa_circ_0119412 in HCC advancement. The qRT-PCR was done to estimate the expressions of hsa_circ_0119412, miR-526b-5p, and Stathmin 1 (STMN1) in HCC (clinical samples and cell lines), and immunoblotting was used to detect STMN1 protein level in HCC cell lines. The stability of the circRNA was checked by processing with ribonuclease R. The proliferative potential of HCC cells was examined via the CCK-8 assay and the migratory potential by the wound healing assay. Immunoblotting was done to examine Bax and Bcl-2 (apoptosis-related proteins). Luciferase and RIP assays were employed to establish the direct interactions among miR-526b-5p and hsa_circ 0119412/STMN1. In vivo tumor growth was measured by doing a xenograft tumor experiment. In the tissues of HCC patients and cell lines derived from HCC cells, hsa_circ_0119412 was distinctly over-expressed. Knocking down hsa_circ_0119412 impeded proliferation and migration while inducing apoptosis in HCC cells. Moreover, silencing hsa_circ_0119412 diminished tumor weight and volume in vivo. Interestingly, miR-526b-5p inhibition partially restored the anti-tumor effects of silencing hsa_circ_0119412. STMN1 expression was also abundant in HCC, suggesting that it play a tumor-promoting role. Mechanistically, hsa_circ_0119412 sponged miR-526b-5p, resulting in STMN1 upregulation and thus facilitating the progression of HCC. In conclusion, this study reveals that hsa_circ_0119412 knockdown attenuates the progression of HCC by targeting miR-526b-5p/STMN1 axis.

High Tumoral STMN1 Expression Is Associated with Malignant Potential and Poor Prognosis in Patients with Neuroblastoma.

Stathmin 1 (STMN1), a marker for immature neurons and tumors, controls microtubule dynamics by destabilizing tubulin. It plays an essential role in cancer progression and indicates poor prognosis in several cancers. This potential protein has not been clarified in clinical patients with neuroblastoma. Therefore, this study aimed to assess the clinical significance and STMN1 function in neuroblastoma with and without MYCN amplification. Using immunohistochemical staining, STMN1 expression was examined in 81 neuroblastoma samples. Functional analysis revealed the association among STMN1 suppression, cellular viability, and endogenous or exogenous MYCN expression in neuroblastoma cell lines. High levels of STMN1 expression were associated with malignant potential, proliferation potency, and poor prognosis in neuroblastoma. STMN1 expression was an independent prognostic factor in patients with neuroblastoma. Furthermore, STMN1 knockdown inhibited neuroblastoma cell growth regardless of endogenous and exogenous MYCN overexpression. Our data suggest that assessing STMN1 expression in neuroblastoma could be a powerful indicator of prognosis and that STMN1 might be a promising therapeutic candidate against refractory neuroblastoma with and without MYCN amplification.

Stathmin 1 and p53 Expression in Cutaneous Squamous Cell Carcinoma and Precursor Lesions.

Studies on the relationship between stathmin 1 (STMN1) and cutaneous squamous cell carcinoma (cSCC) are limited. We aimed to evaluate the relationship between clinicopathological factors and STMN1 and p53 expressions in cSCC and compare them with those in the precursor lesions of cSCC and normal tissue. A total of 195 patients, followed between January 2014 and December 2021, with diagnoses of primary cSCC (n = 129), in situ cSCC (n = 20), or actinic keratosis (n = 46), as well as 29 histopathologically normal tissue samples, were included in the study. Immunohistochemical staining for STMN1 and p53 was performed. In the cSCC group, STMN1 scores were higher in poorly differentiated ( P = 0.001) and ulcerated ( P < 0.001) tumors. A linear relationship between STMN1 score and tumor area, tumor thickness, and mitosis was found ( P = 0.001, P = 0.003, and P < 0.001, respectively). There was no statistically significant correlation between STMN1 and p53 scores. Our results support the previous view that STMN1 may be associated with some adverse clinicopathological and high-risk features of cSCC. To the best of our knowledge, this is the first and largest study to investigate STMN1 expression in cSCC, precancerous lesions of cSCC, and normal tissues.

Stathmin1 promotes lymph node metastasis in hypopharyngeal squamous cell carcinoma via regulation of HIF‑1α/VEGF‑A axis and MTA1 expression.

Extensive neck lymph node metastasis (LNM) is an important clinical feature of hypopharyngeal squamous cell carcinoma (HSCC). Stathmin1 (STMN1) is closely associated with LNM in numerous human cancers. In the present study, the association between STMN1 and neck LNM in HSCC and the underlying molecular mechanisms were explored. First, postoperative samples of HSCC were screened and the association between STMN1 and neck LNM in HSCC was analyzed. Then, cell functional experiments were performed to assess the potential of STMN1 to promote invasion and migration. Subsequently, the potential target genes and pathways of STMN1 were predicted using bioinformatics analysis. Finally, the obtained target genes and pathways of STMN1 were validated by reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses to confirm the potential mechanisms by which STMN1 promotes LNM in HSCC. As a result, a total of 117 postoperative samples of HSCC were screened, and STMN1 was proven to be associated with neck LNM in HSCC. Further, cell functional experiments established that high expression of STMN1 could actually promote FaDu cell invasion and metastasis. Bioinformatics analysis revealed that high expression of STMN1 was associated with the activation of hypoxia inducible factor-1alpha (HIF-1α) pathway and increased expression of metastasis-associated protein 1 (MTA1). Finally, RT-qPCR and western blot analyses confirmed that STMN1 promotes the expression levels of HIF-1α/vascular endothelial growth factor (VEGF)-A and MTA1 in FaDu cell lines. In conclusion, it was found that high expression of STMN1 promoted neck LNM in HSCC and the potential mechanisms may be via regulation of the HIF-1α/VEGF-A axis and MTA1 expression.

The prognostic role of a phospho-Stathmin 1 signature in breast cancer treated with neoadjuvant chemotherapy

High expression of Stathmin 1 (STMN1) protein is related to a poor prognosis in various tumors, including breast cancer. In our previous study, a phospho-STMN1 signature was conducted to predict outcomes in adjuvantly treated breast cancer patients. This study aimed to explore the relationship of STMN1 expression with our phospho-STMN1 signature and the prognosis of patients treated with neoadjuvant chemotherapy (NACT). A retrospective analysis of 116 patients who received NACT in The First Affiliated Hospital of Sun Yat-sen University between December 2008 and March 2016 was conducted. Patients were followed up through telephone once a year until 2022. The levels of STMN1, Ser16, Ser25, Ser38, and Ser63 phosphorylation and GRP78 expression in pre-NACT biopsy specimens from the patients were detected by immunohistochemistry. The recurrence risk score for each patient was calculated using the p-STMN1/GRP78 model. Clinical and pathological parameters, pathological complete response and objective response rates, and survival data were analyzed. In patients with NACT-treated breast cancer, high levels of STMN1, Ser25 phosphorylation, Ser38 phosphorylation, and GRP78 were related to worse disease-free survival (DFS), as was a high p-STMN1/GRP78 model risk score. In contrast, high Ser16 and Ser63 phosphorylation levels were related to better DFS [p-STMN1/GRP78 model: P=0.002, HR =0.180 (0.061-0.534); STMN1: P=0.001, HR =0.290 (0.147-0.572); Ser16: P=0.036, HR =2.019 (1.049-3.886); Ser25: P=0.013, HR =0.392 (0.188-0.819); Ser38: P=0.001, HR =0.293 (0.153-0.559); Ser63: P=0.006, HR =3.346 (1.407-7.961); GRP78: P=0.010, HR =0.417 (0.214-0.815)]. However, no significant statistical difference was found in the multivariate regression. The relationship between these markers and the therapeutic effect of NACT (pathological complete response and objective response) showed the same tendency with survival. The area under the receiver operating characteristic curve for the p-STMN1/GRP78 model was 0.790 (P=0.001) with sensitivity of 70% and specificity of 74%. The expression and serine phosphorylation status of STMN1 may be beneficial as biomarkers for predicting the prognosis of breast cancer patients treated with NACT. Our p-STMN1/GRP78 model could become a widely applied signature for assessing the metastatic risk of breast cancer patients, potentially facilitating their individualized management before NACT.

STMN1 as a novel prognostic biomarker in HCC correlating with immune infiltrates and methylation

BackgroundUpregulation of Stathmin 1 (STMN1), a cytoplasmic phosphoprotein that controls the dynamics of cellular microtubules, is linked to malignant behavior and poor prognosis in a range of malignancies. However, little research has been done on STMN1’s potential role in HCC as a single factor in DNA methylation, m6A, or immunological modulation.ResultsSTMN1 is overexpressed in hepatocellular carcinoma, where it is related to clinicopathological parameters and affects the prognosis of HCC patients. STMN1 overexpression plays an important role in the diagnosis and prognosis of hepatocellular carcinoma. Meanwhile, methylation of 7 CpG sites of STMN1 in HCC was correlated with prognosis, and STMN1 expression was closely related to m6A modification. In addition, STMN1 expression is associated with immune cell infiltration, immune molecules, and immune checkpoints in HCC.ConclusionSTMN1 has a significant role in hepatocellular carcinoma diagnosis and prediction. STMN1 is implicated not just in the onset and course but also in the immunological modulation of the disease. DNA methylation and m6A are both linked to STMN1. Therefore, STMN1 could be used as a diagnostic and prognostic biomarker for HCC, as well as a target for immunotherapy.

Relevance of Additional Immunohistochemical Markers in the Differential Diagnosis of Small B-Cell Lymphomas: A Case-Control Study

Objective:Clinical and pathological differential diagnosis of small B-cell lymphomas (SBCLs) is still controversial and may be difficult due to their overlapping morphology, phenotype, and differentiation to plasma cells. We aimed to examine the expression of the immune receptor translocation-associated protein 1 (IRTA1), myeloid cell nuclear differentiation antigen (MNDA), lymphoid enhancer-binding factor-1 (LEF1), and stathmin 1 (STMN1) markers in SBCL cases involving different sites that may have plasma cell differentiation.Materials and Methods:We studied 154 tissue samples with lymphoma involvement from 116 patients and evaluated the staining distribution of the markers. Expressions were evaluated in 21 chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), 7 follicular lymphoma (FL), 14 nodal marginal zone lymphoma, 17 extranodal marginal zone lymphoma, 55 splenic marginal zone lymphoma, 22 marginal zone lymphoma-not otherwise specified, and 18 lymphoplasmacytic lymphoma/Waldenström macroglobulinemia cases by immunohistochemistry.Results:The results confirmed that LEF1 was the most sensitive and specific marker for CLL/SLL and STMN1 was the most sensitive and specific marker for FL (p<0.001). MNDA and IRTA1 were useful markers to distinguish marginal zone lymphomas.Conclusion:Our results suggest that LEF1 for CLL/SLL and STMN1 for FL are reliable markers. LEF1, MNDA, STMN1, and IRTA1 are helpful with other routinely used immunohistochemical markers in a diagnostic algorithm considering their limitations.

Stathmins and Motor Neuron Diseases: Pathophysiology and Therapeutic Targets.

Motor neuron diseases (MNDs) are a group of fatal, neurodegenerative disorders with different etiology, clinical course and presentation, caused by the loss of upper and lower motor neurons (MNs). MNs are highly specialized cells equipped with long, axonal processes; axonal defects are some of the main players underlying the pathogenesis of these disorders. Microtubules are key components of the neuronal cytoskeleton characterized by dynamic instability, switching between rapid polymerization and shrinkage. Proteins of the stathmin family affect microtubule dynamics regulating the assembly and the dismantling of tubulin. Stathmin-2 (STMN2) is one of the most abundantly expressed genes in MNs. Following axonal injury, STMN2 expression is upregulated, and the protein is transported toward the growth cones of regenerating axons. STMN2 has a critical role in axonal maintenance, and its dysregulation plays an important role in neurodegenerative processes. Stathmin-1 (STMN1) is a ubiquitous protein that is highly expressed during the development of the nervous system, and its phosphorylation controls microtubule dynamics. In the present review, we summarize what is currently known about the involvement of stathmin alterations in MNDs and the potential therapeutic effect of their modulation, with a specific focus on the most common forms of MND, amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA).

Overexpression of Stathmin 1 Predicts Poor Prognosis and Promotes Cancer Cell Proliferation and Migration in Ovarian Cancer.

Purpose The aim of this study was to investigate the expression of stathmin 1 (STMN1) in ovarian cancer and its effect on prognosis. The effect and mechanism of STMN1 on the proliferation and migration of ovarian cancer cells were also investigated. Methods Expression of STMN1 was measured by immunohistochemical staining in ovarian cancer tissues. The effects of STMN1 on the proliferation and migration capacity of ovarian cancer were evaluated using Cell Counting Kit-8 (CCK-8) assays, colony formation assays, immunofluorescence staining, wound healing assays, and Transwell assays. Transcription factors were predicted by bioinformatic analysis of TCGA database. Results STMN1 was upregulated in ovarian cancer tissues as compared to paracancerous tissues and associated with shorter overall survival. STMN1 expression significantly correlated with FIGO staging and tumor differentiation (P < 0.05). Furthermore, STMN1 promoted proliferation and migration in ovarian cancer cell lines. Bioinformatic analysis revealed that STMN1 was potentially regulated by E2F transcription factors. Then, we found that E2F1 regulated the expression of STMN1 and affected proliferation. Conclusion STMN1 is overexpressed in ovarian cancer, and its high expression suggests a poor prognosis. STMN1 promotes the proliferation and migration of ovarian cancer and is regulated by E2F1. Thus, STMN1 may serve as a negative prognostic factor and possible target for the treatment of ovarian cancer patients.

Stathmin 1 is a biomarker for diagnosis of microvascular invasion to predict prognosis of early hepatocellular carcinoma

Microvascular invasion (MVI) is presently evaluated as a high-risk factor to be directly relative to postoperative prognosis of hepatocellular carcinoma (HCC). Up to now, diagnosis of MVI mainly depends on the postoperative pathological analyses with H&E staining assay, based on numbers and distribution characteristics of MVI to classify the risk levels of MVI. However, such pathological analyses lack the specificity to discriminate MVI in HCC specimens, especially in complicated pathological tissues. In addition, the efficiency to precisely define stages of MVI is not satisfied. Thus, any biomarker for both conforming diagnosis of MVI and staging its levels will efficiently and effectively promote the prediction of early postoperative recurrence and metastasis for HCC. Through bioinformatics analysis and clinical sample verification, we discovered that Stathmin 1 (STMN1) gene was significantly up-regulated at the locations of MVI. Combining STMN1 immunostaining with classic H&E staining assays, we established a new protocol for MVI pathological diagnosis. Next, we found that the degrees of MVI risk could be graded according to expression levels of STMN1 for prognosis prediction on recurrence rates and overall survival in early HCC patients. STMN1 affected epithelial-mesenchymal transformation (EMT) of HCC cells by regulating the dynamic balance of microtubules through signaling of “STMN1-Microtubule-EMT” axis. Inhibition of STMN1 expression in HCC cells reduced their lung metastatic ability in recipients of mouse model, suggesting that STMN1 also could be a potential therapeutic target for inhibiting HCC metastasis. Therefore, we conclude that STMN1 has potentials for clinical applications as a biomarker for both pathological diagnosis and prognostic prediction, as well as a therapeutic target for HCC.

STMN1 promotes the proliferation and inhibits the apoptosis of acute myeloid leukemiacells by activating the PI3K/Akt pathway

Recent studies have shown that the microtubule disrupting protein Stathmin 1 (STMN1) is differentially expressed in AML patients and healthy control. The aim of this study was to explore the effects and molecular mechanism of STMN1 in AML. Here, the expression of STMN1 in peripheral blood cells (PBMCs) and bone marrow of AML patients and healthy volunteers was detected by RT-PCR and Western blot. STMN1 expression was regulated by transfected with STMN1 overexpressed plasmid or shRNA in two human leukemia cell lines K562 and HL60. Cell proliferation was examined by CCK8 and Edu staining. Annexin V and TUNEL assays were applied to test cell apoptosis. Flow cytometry was used to test the cell cycle distribution. The activation of the PI3K signaling pathway and the expression levels of cell cycle and cell apoptosis-related protein were determined by Western blot. In this study, we found that STMN1 was overexpressed in PBMCs and bone marrow of AML patients. STMN1 expression was closely related to FAB subtypes, risk stratification, disease-free survival, and overall survival of AML. Functional assays showed that overexpression of STMN1 in HL60 and K562 cells enhanced cell proliferation, decreased cell apoptosis, and caused G1 phase arrest. In contrast, suppression of STMN1reduced cell proliferation and enhanced cell apoptosis in both HL60 and K562 cells. Moreover, the PI3K/Akt pathway was activated by STMN1, while suppression of STMN1 dysregulated the PI3K/Akt pathway and upregulating the levels of caspases3 and Bax expression. In conclusion, STMN1 was confirmed to promote the proliferation and inhibit the apoptosis of HL60 and K562 cells by modulating the PI3K/Akt pathway. STMN1 might be a novel molecular target for treating AML.

STMN1 promotes the proliferation and inhibits the apoptosis of acute myeloid leukemiacells by activating the PI3K/Akt pathway

Recent studies have shown that the microtubule disrupting protein Stathmin 1 (STMN1) is differentially expressed in AML patients and healthy control. The aim of this study was to explore the effects and molecular mechanism of STMN1 in AML. Here, the expression of STMN1 in peripheral blood cells (PBMCs) and bone marrow of AML patients and healthy volunteers was detected by RT-PCR and Western blot. STMN1 expression was regulated by transfected with STMN1 overexpressed plasmid or shRNA in two human leukemia cell lines K562 and HL60. Cell proliferation was examined by CCK8 and Edu staining. Annexin V and TUNEL assays were applied to test cell apoptosis. Flow cytometry was used to test the cell cycle distribution. The activation of the PI3K signaling pathway and the expression levels of cell cycle and cell apoptosis-related protein were determined by Western blot. In this study, we found that STMN1 was overexpressed in PBMCs and bone marrow of AML patients. STMN1 expression was closely related to FAB subtypes, risk stratification, disease-free survival, and overall survival of AML. Functional assays showed that overexpression of STMN1 in HL60 and K562 cells enhanced cell proliferation, decreased cell apoptosis, and caused G1 phase arrest. In contrast, suppression of STMN1reduced cell proliferation and enhanced cell apoptosis in both HL60 and K562 cells. Moreover, the PI3K/Akt pathway was activated by STMN1, while suppression of STMN1 dysregulated the PI3K/Akt pathway and upregulating the levels of caspases3 and Bax expression. In conclusion, STMN1 was confirmed to promote the proliferation and inhibit the apoptosis of HL60 and K562 cells by modulating the PI3K/Akt pathway. STMN1 might be a novel molecular target for treating AML.

SiRNA-mediated stathmin1 silencing inhibits proliferation of prostate carcinoma cell line.

Stathmin1 (STMN1) has been proposed as a possible prognostic marker and a potential therapeutic target for some cancers. We aimed to analyze the changes in autophagy, invasion, apoptosis-related genes in prostate cancer (PCa) cell line (PC-3), after small interfering RNA (siRNA)-mediated STMN1 silencing, and also the relationships of STMN1 expression, clinicopathological parameters, and survival (OS) in PCa cases. The STMN1 expressions were analyzed, immunohistochemically, in formalin-fixed paraffin-embedded 75 PCa and 15 benign prostatic hypertrophy (BPH) tissues. The correlation between the levels of expression STMN1, clinicopathological features, and OS was determined in PCa cases. The siRNA-mediated STMN1 incubated PC-3 cells were transfected and compared to negative control siRNAs. We determined mRNA levels in autophagy, invasion, and apoptosis genes with the combination of reverse transcription-polymerase chain reaction (RT-PCR) and western blotting in PC3 cell lines after STMN1 silencing. It was determined that STMN1 was overexpressed significantly in PCa cases, immunohistochemically. The overexpression of STMN1 was significantly correlated with the high-grade Gleason score, and it was associated with a worse prognosis of PCa cases according to the Kaplan-Meier survival analysis (p < 0.05). Significant silencing in STMN1 was determined (87.5%) after siRNA applications. Especially, invasion genes such as claudin 7, fibroblast growth factor 8, hypoxia-inducible factor 1 subunit alpha, hepatocyte growth factor, matrix metallopeptidase 2, 7 genes, markedly, decreased by siRNA-mediated STMN1silencing. STMN1 silencing was determined to significantly increase caspase 3 protein expression by using western blot analysis (p < 0.001). Although STMN1 silencing did not have a significant effect on the induction of apoptosis and autophagy-related genes in PCa cells, it was shown to affect apoptotic mechanisms through the caps3 protein. siRNA-mediated STMN1 silencing decreases proliferation in the PCa cell line. It is thought that STMN1 can serve as a potential therapeutic target in the advanced stage-PCa, especially.

STMN1 is highly expressed and contributes to clonogenicity in acute promyelocytic leukemia cells.

Stathmin 1 (STMN1) is a microtubule-destabilizing protein highly expressed in hematological malignancies and involved in proliferation and differentiation. Although a previous study found that the PML-RARα fusion protein, which contributes to the pathophysiology of acute promyelocytic leukemia (APL), positively regulates STMN1 at the transcription and protein activity levels, little is known about the role of STMN1 in APL. In this study, we aimed to investigate the STMN1 expression levels and their associations with laboratory, clinical, and genomic data in APL patients. We also assessed the dynamics of STMN1 expression during myeloid cell differentiation and cell cycle progression, and the cellular effects of STMN1 silencing and pharmacological effects of microtubule-stabilizing drugs on APL cells. We found that STMN1 transcripts were significantly increased in samples from APL patients compared with those of healthy donors (all p < 0.05). However, this had no effect on clinical outcomes. STMN1 expression was associated with proliferation- and metabolism-related gene signatures in APL. Our data confirmed that STMN1 was highly expressed in early hematopoietic progenitors and reduced during cell differentiation, including the ATRA-induced granulocytic differentiation model. STMN1 phosphorylation was predominant in a pool of mitosis-enriched APL cells. In NB4 and NB4-R2 cells, STMN1 knockdown decreased autonomous cell growth (all p < 0.05) but did not impact ATRA-induced apoptosis and differentiation. Finally, treatment with paclitaxel (as a single agent or combined with ATRA) induced microtubule stabilization, resulting in mitotic catastrophe with repercussions for cell viability, even in ATRA-resistant APL cells. This study provides new insights into the STMN1 functions and microtubule dynamics in APL.

Dysregulated non-coding telomerase RNA component and associated exonuclease XRN1 in leucocytes from women developing preeclampsia-possible link to enhanced senescence

Senescence in placenta/fetal membranes is a normal phenomenon linked to term parturition. However, excessive senescence which may be induced by telomere attrition, has been associated with preeclampsia (PE). We hypothesized that the telomerase complex in peripheral blood mononuclear cells (PBMC) and circulating telomere associated senescence markers would be dysregulated in women with PE. We measured long non-coding (nc) RNA telomerase RNA component (TERC) and RNAs involved in the maturation of TERC in PBMC, and the expression of TERC and 5′–3′ Exoribonuclease 1 (XRN1) in extracellular vesicles at 22–24 weeks, 36–38 weeks and, 5-year follow-up in controls and PE. We also measured telomere length at 22–24 weeks and 5-year follow-up. The circulating senescence markers cathelicidin antimicrobial peptide (CAMP), β-galactosidase, stathmin 1 (STMN1) and chitotriosidase/CHIT1 were measured at 14–16, 22–24, 36–38 weeks and at 5-year follow-up in the STORK study and before delivery and 6 months post-partum in the ACUTE PE study. We found decreased expression of TERC in PBMC early in pregnant women who subsequently developed PE. XRN1 involved in the maturation of TERC was also reduced in pregnancy and 5-year follow-up. Further, we found that the senescence markers CAMP and β-galactosidase were increased in PE pregnancies, and CAMP remained higher at 5-year follow-up. β-galactosidase was associated with atherogenic lipid ratios during pregnancy and at 5-year follow-up, in PE particularly. This study suggests a potential involvement of dysfunctional telomerase biology in the pathophysiology of PE, which is not restricted to the placenta.