Stathmin 1, a marker of PI3K pathway activation and regulator of microtubule dynamics, is expressed in early pelvic serous carcinomas

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.

Involvement of Protease-Activated Receptor2 Pleckstrin Homology Binding Domain in Ovarian Cancer: Expression in Fallopian Tubes and Drug Design

Studying primordial events in cancer is pivotal for identifying predictive molecular indicators and for targeted intervention. While the involvement of G-protein-coupled receptors (GPCRs) in cancer is growing, GPCR-based therapies are yet rare. Here, we demonstrate the overexpression of protease-activated receptor 2 (PAR2), a GPCR member in the fallopian tubes (FTs) of high-risk BRCA carriers as compared to null in healthy tissues of FT. FTs, the origin of ovarian cancer, are known to express genes of serous tubal intraepithelial carcinoma (STICs), a precursor lesion of high-grade serous carcinoma (HGSC). PAR2 expression in FTs may serve as an early prediction sensor for ovarian cancer. We show now that knocking down Par2 inhibits ovarian cancer peritoneal dissemination in vivo, pointing to the central role of PAR2. Previously we identified pleckstrin homology (PH) binding domains within PAR1,2&4 as critical sites for cancer-growth. These motifs associate with PH-signal proteins via launching a discrete signaling network in cancer. Subsequently, we selected a compound from a library of backbone cyclic peptides generated toward the PAR PH binding motif, namely the lead compound, Pc(4-4). Pc(4-4) binds to the PAR PH binding domain and blocks the association of PH-signal proteins, such as Akt or Etk/Bmx with PAR2. It attenuates PAR2 oncogenic activity. The potent inhibitory function of Pc(4-4) is demonstrated via inhibition of ovarian cancer peritoneal spread in mice. While the detection of PAR2 may serve as a predictor for ovarian cancer, the novel Pc(4-4) compound may serve as a powerful medicament in STICs and ovarian cancer. This is the first demonstration of the involvement of PAR PH binding motif signaling in ovarian cancer and Pc(4-4) as a potential therapy treatment.

A Cellular atlas of the human fallopian tube reveals the metamorphosis of secretory epithelial cells during the menstrual cycle and menopause

The fallopian tube, connecting the uterus with the ovary, is a dynamic organ that undergoes cyclical changes and is the site of several diseases, including serous cancer. Here, we use single-cell technologies to construct a comprehensive cell map of healthy pre-menopausal fallopian tubes, capturing the impact of the menstrual cycle and menopause on different fallopian tube cells at the molecular level. The comparative analysis between pre- and post-menopausal fallopian tubes reveals substantial shifts in cellular abundance and gene expression patterns, highlighting the physiological changes associated with menopause. Further investigations into menstrual cycle phases illuminate distinct molecular states in secretory epithelial cells caused by hormonal fluctuations. The markers we identified characterizing secretory epithelial cells provide a valuable tool for classifying ovarian cancer subtypes.

Graphical summary

Graphical summary of results. During the proliferative phase (estrogen high ) of the menstrual cycle, SE2 cells (OVGP1 + ) dominate the fallopian tube (FT) epithelium, while SE1 cells (OVGP1 - ) dominate the epithelium during the secretory phase. Though estrogen levels decrease during menopause, SE post-cells (OVGP1 + , CXCL2 + ) make up most of the FT epithelium.

A Novel Trojan Horse Nanotherapy Strategy Targeting the cPKM-STMN1/TGFB1 Axis for Effective Treatment of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is characterized by its dense fibrotic microenvironment and highly malignant nature, which are associated with chemotherapy resistance and very poor prognosis. Although circRNAs have emerged as important regulators in cancer biology, their role in ICC remains largely unclear. Herein, a circular RNA, cPKM is identified, which is upregulated in ICC and associated with poor prognosis. Silencing cPKM in ICC cells reduces TGFB1 release and stromal fibrosis, inhibits STMN1 expression, and suppresses ICC growth and metastasis, moreover, it also leads to overcoming paclitaxel resistance. This is regulated by the interactions of cPKM with miR-199a-5p or IGF2BP2 and by the ability of cPKM to stabilize STMN1/TGFB1 mRNA. Based on these findings, a Trojan horse nanotherapy strategy with co-loading of siRNA against cPKM (si-cPKM) and paclitaxel (PTX) is developed. The siRNA/PTX co-loaded nanosystem (Trojan horse) efficiently penetrates tumor tissues, releases si-cPKM and paclitaxel (soldiers), promotes paclitaxel sensitization, and suppresses ICC proliferation and metastasis in vivo. Furthermore, it alleviates the fibrosis of ICC tumor stroma and reopens collapsed tumor vessels (opening the gates), thus enhancing the efficacy of the standard chemotherapy regimen (main force). This novel nanotherapy provides a promising new strategy for ICC treatment.

STNM1 in human cancers: role, function and potential therapy sensitizer

STMN1 belongs to the stathmin gene family, it encodes a cytoplasmic phosphorylated protein, stathmin1, which is commonly observed in vertebrate cells. STMN1 is a structural microtubule-associated protein (MAP) that binds to microtubule protein dimers rather than microtubules, with each STMN1 binding two microtubule protein dimers and preventing their aggregation, leading to microtubule instability. STMN1 expression is elevated in a number of malignancies, and inhibition of its expression can interfere with tumor cell division. Its expression can change the division of tumor cells, thereby arresting cell growth in the G2/M phase. Moreover, STMN1 expression affects tumor cell sensitivity to anti-microtubule drug analogs, including vincristine and paclitaxel. The research on MAPs is limited, and new insights on the mechanism of STMN1 in different cancers are emerging. The effective application of STMN1 in cancer prognosis and treatment requires further understanding of this protein. Here, we summarize the general characteristics of STMN1 and outline how STMN1 plays a role in cancer development, targeting multiple signaling networks and acting as a downstream target for multiple microRNAs, circRNAs, and lincRNAs. We also summarize recent findings on the function role of STMN1 in tumor resistance and as a therapeutic target for cancer.

A comprehensive immunohistochemical analysis of 26 markers in 250 cases of serous ovarian tumors

BACKGROUND

We examined a large cohort of serous tubo-ovarian tumors with 26 immunohistochemical markers, with the aim to assess their value for differential diagnosis and prognosis.

METHODS

Immunohistochemical analyses with 26 immunomarkers were performed on 250 primary tubo-ovarian tumors including 114 high grade serous carcinomas (HGSC), 97 low grade serous carcinomas (LGSC), and 39 serous borderline tumors (micropapillary variant, mSBT). The associations of overall positivity with clinicopathological characteristics were evaluated using the chi-squared test or Fisher's Exact test.

RESULTS

We found significantly different expression of p53, p16, ER, PR, PTEN, PAX2, Mammaglobin, RB1, Cyclin E1, stathmin, LMP2, L1CAM, CD44, and Ki67 in HGSCs compared to LGSCs. No significant differences were found between LGSC and mSBT. None of the other included markers (PAX8, ARID1A, HNF1B, Napsin A, CDX2, SATB2, MUC4, BRG1, AMACR, TTF1, BCOR, NTRK) showed any differences between the investigated serous tumors. Regarding the prognosis, only PR and stathmin showed a statistically significant prognostic meaning in LGSCs, with better overall survival (OS) and recurrence-free survival (RFS) in cases positive for PR, and worse outcome (RFS) for stathmin. None of the study markers showed prognostic significance in HGSCs.

CONCLUSION

We provided an extensive immunohistochemical analysis of serous ovarian/tubo-ovarian tumors. Although we found some differences in the expression of some markers in HGSCs compared to LGSCs, only p53, p16, and Ki67 seem to be useful in real diagnostic practice. We also suggested the best discriminative cut-off for Ki67 (10% of positive tumor cells) for distinguishing HGSC from LGSC. We found prognostic significance of PR and stathmin in LGSCs. Moreover, the high expression of stathmin could also be of predictive value in ovarian carcinomas as target-specific anti-stathmin effectors are potential therapeutic targets.

In Silico Pan-Cancer Analysis Reveals Prognostic Role of the Erythroferrone (ERFE) Gene in Human Malignancies

The erythroferrone gene (ERFE), also termed CTRP15, belongs to the C1q tumor necrosis factor-related protein (CTRP) family. Despite multiple reports about the involvement of CTRPs in cancer, the role of ERFE in cancer progression is largely unknown. We previously found that ERFE was upregulated in erythroid progenitors in myelodysplastic syndromes and strongly predicted overall survival. To understand the potential molecular interactions and identify cues for further functional investigation and the prognostic impact of ERFE in other malignancies, we performed a pan-cancer in silico analysis utilizing the Cancer Genome Atlas datasets. Our analysis shows that the ERFE mRNA is significantly overexpressed in 22 tumors and affects the prognosis in 11 cancer types. In certain tumors such as breast cancer and adrenocortical carcinoma, ERFE overexpression has been associated with the presence of oncogenic mutations and a higher tumor mutational burden. The expression of ERFE is co-regulated with the factors and pathways involved in cancer progression and metastasis, including activated pathways of the cell cycle, extracellular matrix/tumor microenvironment, G protein-coupled receptor, NOTCH, WNT, and PI3 kinase-AKT. Moreover, ERFE expression influences intratumoral immune cell infiltration. Conclusively, ERFE is aberrantly expressed in pan-cancer and can potentially function as a prognostic biomarker based on its putative functions during tumorigenesis and tumor development.

Spatial Transcriptomic Analysis of Ovarian Cancer Precursors Reveals Reactivation of IGFBP2 during Pathogenesis

Elucidating the earliest pathogenic steps in cancer development is fundamental to improving its early detection and prevention. Ovarian high-grade serous carcinoma (HGSC), a highly aggressive cancer, mostly originates from the fallopian tube epithelium through a precursor stage, serous tubal intraepithelial carcinoma (STIC). In this study, we performed spatial transcriptomic analysis to compare STICs, carcinoma, and their matched normal fallopian tube epithelium. Several differentially expressed genes in STICs and carcinomas were involved in cancer metabolism and detected in a larger independent transcriptomic dataset of ovarian HGSCs. Among these, insulin-like growth factor binding protein-2 (IGFBP2) was found to undergo DNA hypomethylation and to be increased at the protein level in STICs. Pyrosequencing revealed an association of IGFBP2 expression with the methylation state of its proximal enhancer, and 5-azacytidine treatment increased IGFBP2 expression. In postmenopausal fallopian tubes, where most STICs are detected, IGFBP2 immunoreactivity was detected in all 38 proliferatively active STICs but was undetectable in morphologically normal tubal epithelia, including those with TP53 mutations. In premenopausal fallopian tubes, IGFBP2 expression was limited to the secretory epithelium at the proliferative phase, and estradiol treatment increased IGFBP2 expression levels. IGFBP2 knockdown suppressed the growth of IGFBP2-expressing tubal epithelial cells via inactivation of the AKT pathway. Taken together, demethylation of the proximal enhancer of IGFBP2 drives tumor development by maintaining the increased IGFBP2 required for proliferation in an otherwise estrogen-deprived, proliferation-quiescent, and postmenopausal tubal microenvironment.

SIGNIFICANCE

Molecular studies of the earliest precursor lesions of ovarian cancer reveal a role of IGFBP2 in propelling tumor initiation, providing new insights into ovarian cancer development.

L1CAM is required for early dissemination of fallopian tube carcinoma precursors to the ovary

Most ovarian high-grade serous carcinomas (HGSC) arise from Serous Tubal Intraepithelial Carcinoma (STIC) lesions in the distal end of the fallopian tube (FT). Formation of STIC lesions from FT secretory cells leads to seeding of the ovarian surface, with rapid tumor dissemination to other abdominal structures thereafter. It remains unclear how nascent malignant cells leave the FT to colonize the ovary. This report provides evidence that the L1 cell adhesion molecule (L1CAM) contributes to the ability of transformed FT secretory cells (FTSEC) to detach from the tube, survive under anchorage-independent conditions, and seed the ovarian surface. L1CAM was highly expressed on the apical cells of STIC lesions and contributed to ovarian colonization by upregulating integrins and fibronectin in malignant cells and activating the AKT and ERK pathways. These changes increased cell survival under ultra-low attachment conditions that mimic transit from the FT to the ovary. To study dissemination to the ovary, we developed a tumor-ovary co-culture model. We showed that L1CAM expression was important for FT cells to invade the ovary as a cohesive group. Our results indicate that in the early stages of HGSC development, transformed FTSECs disseminate from the FT to the ovary in a L1CAM-dependent manner.

Immunohistochemical expression of stathmin in oral dysplasia: An original study with an insight of its action on microtubules

Background and Objectives:

Stathmin is a phosphoprotein, which in its phosphorylated/unphosphorylated states plays a major role in polymerization/depolymerization of microtubules, respectively. Assembly of microtubules is an important aspect of cell division called mitosis. Hinderance in the function of stathmin could lead to damage in the mitotic process resulting in aneuploidy which is common manifestation of malignancies. Hence, stathmin could be used as a tumor marker for oral dysplasias and cancers. The purpose of the study is to compare the expression of stathmin in normal subjects to the patients with oral leukoplakia and to correlate its expression with different histopathological grades of oral leukoplakia This is the first ever study conducted to examine the expression of stathmin in oral dysplasia.

Methodology:

Thirty histopathologically confirmed cases of oral dysplasia were selected for the study. These tissues were evaluated immunohistochemically for stathmin. To enumerate the stathmin stained cells, 300 cells were examined manually in at least 5 areas and a mean percentage of positive–stained slides were determined. Then, each sample was assigned to one of the following staining scores: (0) – (<10% of stained cells); (1) – (11%–25% of stained cells); (2) – (26%–50% of stained cells); (3) – (51%–75% of stained cells); (4) – (76%–90% of stained cells) and (5) – (91%–100% of stained cells). The results were analyzed statistically using ANNOVA test.

Results:

When comparison was made with respect to staining scores of stathmin between normal and dysplasia groups, the results were found to be statistically significant with a P = 0.0001. A statistically significant difference was observed between various histopathological grades of dysplasia with respect to stathmin immunohistochemistry scores with a P = 0.0001.

Conclusion:

These results suggest stathmin as a tumor marker and prognostic indicator.

PTEN loss promotes oncogenic function of STMN1 via PI3K/AKT pathway in lung cancer

Among all cancer types, lung cancer has already become the leading cause of cancer-related death around the world. The molecular mechanism understanding this development is still needed to be improved to treat lung cancer. Stathmin (STMN1) was initially identified as a cytoplasmic protein phosphorylated responding to cell signal and controlled cell physiological processes. The dysregulation of STMN1 is found in various kinds of tumors. However, the molecular mechanism of STMN1 regulating lung cancer is still unclear. Here, we found that STMN1 was overexpressed in lung cancer tissues and associated with worse survival rates of lung cancer patients. Inhibition of STMN1 suppressed lung cancer cell growth, migration and invasion, and promoted drug sensitivity. Moreover, PTEN loss promoted STMN1 expression via PI3K/AKT pathway. PTEN loss ameliorated the inhibition of cell growth, migration and invasion, and drug sensitivity induced by STMN1 knockdown in lung cancer. The high expression of STMN1 was negatively correlated with the low expression of PTEN in lung cancer specimens. Overall, our work demonstrated that PTEN regulated the oncogenic function of STMN1 in lung cancer.

Inhibition of CDK4/6 as Therapeutic Approach for Ovarian Cancer Patients: Current Evidences and Future Perspectives

Simple Summary

Altered regulation of the cell cycle is a hallmark of cancer. The recent clinical success of the inhibitors of CDK4 and CDK6 has convincingly demonstrated that targeting cell cycle components may represent an effective anti-cancer strategy, at least in some cancer types. However, possible applications of CDK4/6 inhibitors in patients with ovarian cancer is still under evaluation. Here, we describe the possible biological role of CDK4 and CDK6 complexes in ovarian cancer and provide the rationale for the use of CDK4/6 inhibitors in this pathology, alone or in combination with other drugs. This review, coupling basic, preclinical and clinical research studies, could be of great translational value for investigators attempting to design new clinical trials for the better management of ovarian cancer patients.

Abstract

Alterations in components of the cell-cycle machinery are present in essentially all tumor types. In particular, molecular alterations resulting in dysregulation of the G1 to S phase transition have been observed in almost all human tumors, including ovarian cancer. These alterations have been identified as potential therapeutic targets in several cancer types, thereby stimulating the development of small molecule inhibitors of the cyclin dependent kinases. Among these, CDK4 and CDK6 inhibitors confirmed in clinical trials that CDKs might indeed represent valid therapeutic targets in, at least some, types of cancer. CDK4 and CDK6 inhibitors are now used in clinic for the treatment of patients with estrogen receptor positive metastatic breast cancer and their clinical use is being tested in many other cancer types, alone or in combination with other agents. Here, we review the role of CDK4 and CDK6 complexes in ovarian cancer and propose the possible use of their inhibitors in the treatment of ovarian cancer patients with different types and stages of disease.

Stathmin! An immunohistochemical analysis of the novel marker in Oral Squamous Cell Carcinoma and Oral Leukoplakia

BACKGROUND

Stathmin is an intracellular phosphoprotein that controls the microtubule dynamics by further regulating proper attachment and alignment of chromosomes in a dividing cell. Thus, any mutation or aberrantly expressed protein that reduces the fidelity of spindle assembly will enhance chromosomal instability contributing to aneuploidy. Oral Squamous Cell Carcinoma is an extensively studied malignancy that occurs due to accumulated genetic changes due to carcinogens. The current study is done to evaluate the stathmin role and its expression in OSCC and Oral epithelial dysplasia (OED).

OBJECTIVE

The aim of the present study is to evaluate the role of stathmin in OSCC and Oral dysplasia and also to correlate the expression of Stathmin with respect to the different histopathological grades of OED and OSCC.

MATERIALS AND METHODS

30 neutral buffered formalin fixed, paraffin embedded (FFPE) tissues of Oral Leukoplakia/OED and 30 FFPE tissues of OSCC were subjected to immunohistochemistry with stathmin antibody. Five fields of each case with 300 cells were examined and a mean percentage of positive-stained slides were determined. The percentages were recorded accordingly with their respective histological grades. The results were analysed statistically.

RESULTS

The results of the present study demonstrated higher mean values of stathmin in tissues with OSCC (2.50) compared to leukoplakia (2.11) and normal tissues (0.00) with a high level of statistical significance (0.0001). There is also an increase in the percentage levels of stathmin with increase in the histological grade of differentiation in OSCC as well as leukoplakia.

CONCLUSION

The present study found a statistical correlation between increased grades of the disease with expression levels of stathmin. This confirms that stathmin expression can contribute to disease progression and that stathmin might have a potential role as an early diagnostic biomarker and can be a therapeutic target for OSCC. <br />.

The Origin of Ovarian Cancer Species and Precancerous Landscape

Unlike other human cancers, in which all primary tumors arise de novo, ovarian epithelial cancers are primarily imported from either endometrial or fallopian tube epithelium. The prevailing paradigm in the genesis of high-grade serous carcinoma (HGSC), the most common ovarian cancer, posits to its development in fallopian tubes through stepwise tumor progression. Recent progress has been made not only in gathering terabytes of omics data but also in detailing the histologic-molecular correlations required for looking into, and making sense of, the tissue origin of HGSC. This emerging paradigm is changing many facets of ovarian cancer research and routine gynecology practice. The precancerous landscape in fallopian tubes contains multiple concurrent precursor lesions, including serous tubal intraepithelial carcinoma (STIC), with genetic heterogeneity providing a platform for HGSC evolution. Mathematical models imply that a prolonged time (decades) elapses from the development of a TP53 mutation, the earliest known molecular alteration, to an STIC, followed by a shorter span (6 years) for progression to an HGSC. Genetic predisposition accelerates the trajectory. This timeline may allow for the early diagnosis of HGSC and STIC, followed by intent-to-cure surgery. This review discusses the recent advances in this tubal paradigm and its biological and clinical implications, alongside the promise and challenge of studying STIC and other precancerous lesions of HGSC.

Ovarian Cancer Dissemination-A Cell Biologist's Perspective

Epithelial ovarian cancer (EOC) comprises multiple disease states representing a variety of distinct tumors that, irrespective of tissue of origin, genetic aberrations and pathological features, share common patterns of dissemination to the peritoneal cavity. EOC peritoneal dissemination is a stepwise process that includes the formation of malignant outgrowths that detach and establish widespread peritoneal metastases through adhesion to serosal membranes. The cell biology associated with outgrowth formation, detachment, and de novo adhesion is at the nexus of diverse genetic backgrounds that characterize the disease. Development of treatment for metastatic disease will require detailed characterization of cellular processes involved in each step of EOC peritoneal dissemination. This article offers a review of the literature that relates to the current stage of knowledge about distinct steps of EOC peritoneal dissemination, with emphasis on the cell biology aspects of the process.

CCAAT/enhancer binding protein delta (C/EBPδ) demonstrates a dichotomous role in tumour initiation and promotion of epithelial carcinoma

Background

CCAAT/enhancer binding protein delta (C/EBPδ,CEBPD), a gene part of the highly conserved basic-leucine zipper (b-ZIP) domain of transcriptional factors, is downregulated in 65% of high grade serous carcinomas of the ovary (HGSC). Overexpression of C/EBPδ in different tumours, such as glioblastoma and breast cancer either promotes tumour progression or inhibits growth and has low expression in normal tissue until activated by cytotoxic stressors.

Methods

Higher overall expression of C/EBPδ in the luteal phase of the menstrual cycle prompted us to investigate the role of C/EBPδ in carcinogenesis. In vitro experiments were conducted in fallopian tube cell samples and cancer cell lines to investigate the role of C/EBPδ in proliferation, migration, and the epithelial to mesenchymal transition.

Findings

Expression of C/EBPδ induced premature cellular arrest and decreased soft agar colony formation. Loss of C/EBPδ in epithelial cancer cell lines did not have significant effects on proliferation, yet overexpression demonstrated downregulation of growth, similar to normal fallopian tube cells. C/EBPδ promoted a partial mesenchymal to epithelial (MET) phenotype by upregulating E-cadherin and downregulating Vimentin and N-cadherin in FTE cells and increased migratory activity, which suggests a regulatory role in the epithelial-mesenchymal plasticity of these cells.

Interpretation

Our findings suggest that C/EBPδ regulates the phenotype of normal fallopian tube cells by acting on downstream regulatory factors that are implicated in the development of ovarian serous carcinogenesis.

Fund

This study was funded by the CDMRP Ovarian Cancer program (W81WH-0701-0371, W81XWH-18-1-0072), the Princess Margaret Cancer Centre Foundation, Foundation for Women's Cancer – The Belinda-Sue/Mary-Jane Walker Fund, Colleen's Dream Foundation and Sylvester Comprehensive Cancer Center.

Hypoxia destroys the microstructure of microtubules and causes dysfunction of endothelial cells via the PI3K/Stathmin1 pathway

Background

Endothelial cells (EC) are sensitive to changes in the microenvironment, including hypoxia and ischemia. Disruption of the microtubular network has been reported in cases of ischemia. However, the signaling pathways involved in hypoxia-induced microtubular disruption are unknown. The purpose of this study was to investigate the molecular mechanisms involved in hypoxia-induced microtubular disassembly in human umbilical vein endothelial cells (HUVECs).

Results

HUVECs were cultured under normoxic or hypoxic conditions and pretreated with or without colchicine or paclitaxel. The MTT assay, Transwell assay, trans-endothelial permeability assay, and 5-bromo-2′-deoxy-uridine staining were used to test the survival rate, migration, permeability, and proliferation of cells, respectively. Transmission electron microscopy and phalloidin staining were used to observe the microstructure and polymerization of microtubules. The results show that the functions of HUVECs and the microtubular structure were destroyed by hypoxia, but were protected by paclitaxel and a reactive oxygen species (ROS) inhibitor. We further used western blot, a luciferase assay, and co-immunoprecipitation to describe a non-transcription-independent mechanism for PI3K activation-inhibited microtubular stability mediated by Stathmin1, a PI3K interactor that functions in microtubule depolymerization. Finally, we determined that hypoxia and ROS blocked the interaction between PI3K and Stathmin1 to activate disassembly of microtubules.

Conclusion

Thus, our data demonstrate that hypoxia induced the production of ROS and damaged EC function by destroying the microtubular structure through the PI3K/stathmin1 pathway.

Taking the Tube: From Normal Fallopian Tube Epithelium to Ovarian High-grade Serous Carcinoma

Detailed pathologic studies over the past decade suggest a distal fallopian tube origin for the majority of "ovarian" high-grade serous carcinomas (HGSC). This review will summarize molecular alterations observed in tubal precursors for HGSC, namely p53 signatures and serous tubal intraepithelial carcinomas, and in nonmalignant fallopian tube epithelial cells obtained from women at increased genetic risk for HGSC. Recent experiments investigating the impact of follicular fluid exposure and retrograde menstruation on tumor development in the fallopian tube will also be discussed. These data will be reconciled with traditional ovarian cancer risk factors related to reproductive history.

Sequential molecular changes and dynamic oxidative stress in high-grade serous ovarian carcinogenesis

The mechanism of high-grade serous ovarian cancer (HGSC) development remains elusive. This review outlines recent advances in the understanding of sequential molecular changes associated with the development of HGSC, as well as describes oxidative stress-induced genomic instability and carcinogenesis. This article reviews the English language literature between 2005 and 2017. Clinicopathological features analysis provides a sequential progression of fallopian tubal epithelium to precursor lesions to type 2 HGSC. HGSC may develop over a long time after incessant ovulation and repeated retrograde menstruation via stepwise accumulation of genetic alterations, including PAX2, ALDH1A1, STMN1, EZH2 and CCNE1, which confer positive selection of cells with growth advantages through acquiring driver mutations such as BRCA1/2, p53 or PTEN/PIK3CA. Haemoglobin and iron-induced oxidative stress leads to the emergence of genetic alterations in fallopian tubal epithelium via increased DNA damage and impaired DNA repair. Serous tubal intraepithelial carcinoma (STIC), the likely precursor of HGSC, may be susceptible to DNA double-strand breaks, exhibit DNA replication stress and increase genomic instability. The induction of genomic instability is considered to be a driving mechanism of reactive oxygen species (ROS)-induced carcinogenesis. HGSC exemplifies the view of stepwise cancer development. We describe how genetic alterations emerge during HGSC carcinogenesis related to oxidative stress.

The conceptual advances of carcinogenic sequence model in high-grade serous ovarian cancer

The present review focuses on the current status of molecular pathology in high-grade serous cancer (HGSC) and preneoplastic conditions. This article reviews the English-language literature on HGSC, precursor, fallopian tubal epithelium, secretory cells, ciliated cells, secretory cell expansion, secretory cell outgrowth (SCOUT), p53 signature, serous tubal intraepithelial carcinoma (STIC), DNA damage and immunohistochemistry in an effort to identify the precursor-carcinoma sequence in HGSC. The majority of HGSC originates from the fimbriated end of the fallopian tube secretory epithelial cells, while the small part of this disease may develop from ovarian cortical inclusion cyst (CIC). A series of morphological changes from normal fallopian epithelium to preneoplastic to neoplastic lesions were concomitant with the multistep accumulation of molecular and genetic alterations. Recent studies provide a stepwise progression of fallopian tubal epithelium to precursor lesions to carcinoma, with the aid of a 'secretory cell-SCE-SCOUT-p53 signature-STIC-HGSC sequence' model. Immunohistochemical markers, including p53, STMN1, EZH2, CCNE1, Ki67 and γ-H2AX, were gradually increased during the SCOUT-p53 signature-STIC-HGSC sequence. Conversely, PAX2 expression was decreased during the early phase of SCOUT development. Potential genes and proteins are involved in the evolutionary trajectory of the precursor-cancer lineage model. In the present review we examined detailed aspects of the molecular changes involved in malignant transformation from fallopian tube epithelium to HGSC. A precursor condition originating in 'field cancerization' may gain a growth advantage, leading to HGSC.

High stathmin expression is a marker for poor clinical outcome in endometrial cancer: An NRG oncology group/gynecologic oncology group study

OBJECTIVE

Gynecologic Oncology Group (GOG) 177 demonstrated that addition of paclitaxel to a backbone of adriamycin/cisplatin improves overall survival (OS) and progression-free survival (PFS) for patients with advanced or recurrent endometrial cancer. Using patient specimens from GOG-177, our objective was to identify potential mechanisms underlying the improved clinical response to taxanes. Stathmin (STMN1) is a recognized poor prognostic marker in endometrial cancer that functions as a microtubule depolymerizing protein, allowing cells to transit rapidly through mitosis. Therefore, we hypothesized that one possible mechanism underlying the beneficial effects of paclitaxel could be to counter the impact of stathmin.

METHODS

We analyzed the expression of stathmin by immunohistochemistry (IHC) in 69 specimens from patients enrolled on GOG-177. We also determined the correlation between stathmin mRNA expression and clinical outcomes in The Cancer Genome Atlas (TCGA) dataset for endometrial cancer.

RESULTS

We first established that stathmin expression was significantly associated with shorter PFS and OS for all analyzed cases in both GOG-177 and TCGA. However, subgroup analysis from GOG-177 revealed that high stathmin correlated with poor PFS and OS particularly in patients who received adriamycin/cisplatin only. In contrast, there was no statistically significant association between stathmin expression and OS or PFS in patients treated with paclitaxel/adriamycin/cisplatin.

CONCLUSIONS

Our findings demonstrate that high stathmin expression is a poor prognostic marker in endometrial cancer. Paclitaxel may help to negate the impact of stathmin overexpression when treating high risk endometrial cancer cases.

Stathmin 1 promotes the proliferation and malignant transformation of pancreatic intraductal papillary mucinous neoplasms

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are a type of pancreatic tumor, which have been identified following improvements in diagnostic imaging. However, the malignant transformation of IPMN has been difficult to diagnose clinically. To date, the mechanisms driving the progression of IPMN to cancer remain to be fully elucidated. The present study focused on Stathmin 1 (STMN1), a protein that is associated with the development of various types of cancer. The expression of STMN1 was examined immunohistochemically in tissues from cases of IPMN. The correlation between the STMN1 staining and clinical pathological factors was evaluated, and the expression of STMN1, p27 and S-phase kinase-associated protein 2 (SKP2) were compared. High expression levels of STMN1 were significantly correlated with regions of malignancy, and was associated with high expression of SKP2, low expression of nuclear p27 and a high Ki-67 index. High expression levels of STMN1 and SKP2 were significantly correlated with the transformation of IPMN to carcinoma. In addition, within the regions of carcinoma, the expression of STMN1 was weak in regions of adenoma and high in the cancerous regions. It was concluded that the high expression of STMN1 contributed to tumor proliferation and malignant transformation in the patients with IPMN. These results suggested that characterization of the expression of STMN1 may be a promising approach for predicting malignant transformation of pancreatic intraductal papillary mucinous adenoma.

Clinical significance of UGT1A1 polymorphism and expression of ERCC1, BRCA1, TYMS, RRM1, TUBB3, STMN1 and TOP2A in gastric cancer

BACKGROUND

Individualized therapeutic regimen is a recently intensively pursued approach for targeting diseases, in which the search for biomarkers was considered the first and most important. Thus, the goal of this study was to investigate whether the UGT1A1, ERCC1, BRCA1, TYMS, RRM1, TUBB3, STMN1 and TOP2A genes are underlying biomarkers for gastric cancer, which, to our knowledge, has not been performed.

METHODS

Ninety-eight tissue specimens were collected from gastric cancer patients between May 2012 and March 2015. A multiplex branched DNA liquidchip technology was used for measuring the mRNA expressions of ERCC1, BRCA1, TYMS, RRM1, TUBB3, STMN1 and TOP2A. Direct sequencing was performed for determination of UGT1A1 polymorphisms. Furthermore, correlations between gene expressions, polymorphisms and clinicopathological characteristics were investigated.

RESULTS

The expressions of TYMS, TUBB3 and STMN1 were significantly associated with the clinicopathological characteristics of age, gender and family history of gastric cancer, but not with differentiation, growth patterns, metastasis and TNM staging in patients with gastric cancer. No clinical characteristics were correlated with the expressions of ERCC1, BRCA1, RRM1 and TOP2A. Additionally, patients carrying G allele at -211 of UGT1A1 were predisposed to developing tubular adenocarcinoma, while individuals carrying 6TAA or G allele respectively at *28 or -3156 of UGT1A1 tended to have a local invasion.

CONCLUSIONS

The UGT1A1 polymorphism may be useful to screen the risk population of gastric cancer, while TYMS, TUBB3 and STMN1 may be potential biomarkers for prognosis and chemotherapy guidance.

PAX2 function, regulation and targeting in fallopian tube-derived high-grade serous ovarian cancer

The fallopian tube epithelium (FTE) is one of the progenitor populations for high-grade serous ovarian cancer (HGSC). Loss of PAX2 is the earliest known molecular aberration in the FTE occurring in serous carcinogenesis followed by a mutation in p53. Pathological studies report consistent loss of PAX2 in benign lesions as well as serous tumors. In the current study, the combined loss of PAX2 and expression of the R273H p53 mutant protein in murine oviductal epithelial (MOE) cells enhanced proliferation and growth in soft agar in vitro but was insufficient to drive tumorigenesis in vivo. A serially passaged model was generated to investigate the role of aging, but was also insufficient to drive tumorigenesis. These models recapitulate early benign lesions and suggest that a latency period exists between loss of PAX2, p53 mutation and tumor formation. Stathmin and fut8 were identified as downstream targets regulated by loss of PAX2 and mutation of p53 in MOE cells. Re-expression of PAX2 in PAX2-null human HGSC cells reduced cell survival via apoptosis. Phosphatase and tensin homolog (PTEN)^shRNA negatively regulated PAX2 expression and stable re-expression of PAX2 in MOE:PTEN^shRNA cells significantly reduced proliferation and peritoneal tumor formation in athymic nude mice. PAX2 was determined to be a direct transcriptional target that was activated by wild-type p53, whereas mutant p53 inhibited PAX2 transcription in MOE cells. A small molecule screen using the proximal PAX2 promoter driving luciferase identified four small molecules that were able to enhance PAX2 mRNA expression in MOE cells. PAX2 re-expression in HGSC cells and PTEN-deficient oviductal tumors may have the potential to induce apoptosis. In summary, mutant p53 and PTEN loss negatively regulated PAX2 and PAX2 re-expression in HGSC cells induced cell death.

Genomics of Ovarian Cancer Progression Reveals Diverse Metastatic Trajectories Including Intraepithelial Metastasis to the Fallopian Tube

Accumulating evidence has supported the fallopian tube rather than the ovary as the origin for high-grade serous ovarian cancer (HGSOC). To understand the relationship between putative precursor lesions and metastatic tumors, we performed whole-exome sequencing on specimens from eight HGSOC patient progression series consisting of serous tubal intraepithelial carcinomas (STIC), invasive fallopian tube lesions, invasive ovarian lesions, and omental metastases. Integration of copy number and somatic mutations revealed patient-specific patterns with similar mutational signatures and copy-number variation profiles across all anatomic sites, suggesting that genomic instability is an early event in HGSOC. Phylogenetic analyses supported STIC as precursor lesions in half of our patient cohort, but also identified STIC as metastases in 2 patients. Ex vivo assays revealed that HGSOC spheroids can implant in the fallopian tube epithelium and mimic STIC lesions. That STIC may represent metastases calls into question the assumption that STIC are always indicative of primary fallopian tube cancers.

SIGNIFICANCE

We find that the putative precursor lesions for HGSOC, STIC, possess most of the genomic aberrations present in advanced cancers. In addition, a proportion of STIC represent intraepithelial metastases to the fallopian tube rather than the origin of HGSOC. Cancer Discov; 6(12); 1342-51. ©2016 AACR.See related commentary by Swisher et al., p. 1309This article is highlighted in the In This Issue feature, p. 1293.

CCNE1 amplification and centrosome number abnormality in serous tubal intraepithelial carcinoma: further evidence supporting its role as a precursor of ovarian high-grade serous carcinoma

Aberration in chromosomal structure characterizes almost all cancers and has profound biological significance in tumor development. It can be facilitated by various mechanisms including overexpression of cyclin E1 and centrosome amplification. As ovarian high-grade serous carcinoma has pronounced chromosomal instability, in this study we sought to determine whether increased copy number of CCNE1 which encodes cyclin E1 and centrosome amplification (>2 copies) occurs in its putative precursor, serous tubal intraepithelial carcinoma. We found CCNE1 copy number gain/amplification in 8 (22%) of 37 serous tubal intraepithelial carcinomas and 12 (28%) of 43 high-grade serous carcinomas. There was a correlation in CCNE1 copy number between serous tubal intraepithelial carcinoma and high-grade serous carcinoma in the same patients (P<0.001). There was no significant difference in the percentage of CCNE1 gain/amplification between serous tubal intraepithelial carcinoma and high-grade serous carcinoma (P=0.61). Centrosome amplification was recorded in only 5 (14%) of 37 serous tubal intraepithelial carcinomas, and in 10 (40%) of 25 high-grade serous carcinomas. The percentage of cells with centrosome amplification was higher in high-grade serous carcinoma than in serous tubal intraepithelial carcinoma (P<0.001). Induced expression of cyclin E1 increased the percentage of fallopian tube epithelial cells showing centrosome amplification. Our findings suggest that gain/amplification of CCNE1 copy number occurs early in tumor progression and precedes centrosome amplification. The more prevalent centrosome amplification in high-grade serous carcinoma than in serous tubal intraepithelial carcinoma supports the view that serous tubal intraepithelial carcinoma precedes the development of many high-grade serous carcinomas.

Stathmin-dependent molecular targeting therapy for malignant tumor: the latest 5 years' discoveries and developments

Knowledge of the molecular mechanisms on malignant tumors is very critical for the development of new treatment strategies like molecularly targeted therapies. In last 5 years, many investigations suggest that stathmin is over-expressed in a variety of human malignant tumors, and potentially promotes the occurrence and development of tumors. Rather, down-regulation of stathmin can reduce cell proliferation, motility and metastasis and induce apoptosis of malignant tumors. Thus, a stathmin antagonist, such as a specific inhibitor (antibody, small molecule compound, peptide, or siRNA), may be a novel strategy of molecular targeted therapy. This review summarizes the research progress of recent 5 years on the role of stathmin in tumorigenesis, the molecular mechanisms and development of anti-stathmin treatment, which suggest that continued investigations into the function of stathmin in the tumorigenesis could lead to more rationally designed therapeutics targeting stathmin for treating human malignant tumors.

Rationale for Developing a Specimen Bank to Study the Pathogenesis of High-Grade Serous Carcinoma: A Review of the Evidence

Women with clinically detected high-grade serous carcinomas (HGSC) generally present with advanced-stage disease, which portends a poor prognosis, despite extensive surgery and intensive chemotherapy. Historically, HGSCs were presumed to arise from the ovarian surface epithelium (OSE), but the inability to identify early-stage HGSCs and their putative precursors in the ovary dimmed prospects for advancing our knowledge of the pathogenesis of these tumors and translating these findings into effective prevention strategies. Over the last decade, increased BRCA1/2 mutation testing coupled with performance of risk-reducing surgeries has enabled studies that have provided strong evidence that many, but probably not all, HGSCs among BRCA1/2 mutation carriers appear to arise from the fallopian tubes, rather than from the ovaries. This shift in our understanding of the pathogenesis of HGSCs provides an important opportunity to achieve practice changing advances; however, the scarcity of clinically annotated tissues containing early lesions, particularly among women at average risk, poses challenges to progress. Accordingly, we review studies that have kindled our evolving understanding of the pathogenesis of HGSC and present the rationale for developing an epidemiologically annotated national specimen resource to support this research. Cancer Prev Res; 9(9); 713-20. ©2016 AACR.

Proteomic identification of predictive tissue biomarkers of sensitive to neoadjuvant chemotherapy in squamous cervical cancer

AIMS

The regimens of neoadjuvant chemotherapy (NAC) in squamous cervical cancer (SCC) frequently use cisplatin combined with paclitaxel. Unfortunately, some cervical cancers show resistance to the principal chemotherapeutic agents in the treatment, decreasing the effectiveness of this therapy. The objective of this study was to search for predictive markers of response to NAC in patients with SCC.

MAIN METHODS

Two-dimensional gel electrophoresis (2-DE) accompanied by matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS) was used to analyze and identify differentially expressed proteins in ten cases of advanced cervical cancer patients receiving cisplatin-based NAC. Each of these patients received more than two cycles of NAC. Cell proliferation rate in cisplatin resistant human cervical cancer cell Hela/DDP and its parent cell Hela after treatment with Hsp70 inhibitor and/or cisplatin were tested by MTT assay.

KEY FINDINGS

Twelve protein spots changed in abundance, quantitative comparison of spot volumes showed that seven protein spots were up-regulated and five spots were down-regulated in the NAC non-responders compared to the NAC responders. These proteins are involved in various cellular processes essential for cell metabolism, migration and apoptotic signal transduction. The high-fold changes proteins of stathmin1, Hsp70 and pyruvate kinase isoform M2 were validated by Western blot analysis. Over-expression of Hsp70 inhibits the efficacy of cisplatin. Hsp70 inhibitor enhanced the sensitivity to cisplatin in both Hela and Hela/DDP cells.

SIGNIFICANCE

The study found many candidate proteins involved in chemotherapy resistance/sensitivity, among them Hsp70 might be potential biomarkers to predict the efficacy of chemotherapy for SCC patients.

In vitro and in vivo correlates of physiological and neoplastic human Fallopian tube stem cells

High-grade serous cancer (HGSC) progresses to advanced stages without symptoms and the 5-year survival rate is a dismal 30%. Recent studies of ovaries and Fallopian tubes in patients with BRCA1 or BRCA2 mutations have documented a pre-metastatic intramucosal neoplasm that is found almost exclusively in the Fallopian tube, termed 'serous tubal intraepithelial carcinoma' or STIC. Moreover, other proliferations, termed p53 signatures, secretory cell outgrowths (SCOUTs), and lower-grade serous tubal intraepithelial neoplasms (STINs) fall short of STIC but share similar alterations in expression, in keeping with an underpinning of genomic disturbances involved in, or occurring in parallel with, serous carcinogenesis. To gain insight into the cellular origins of this unique tubal pathway to high-grade serous cancer, we cloned and both immortalized and transformed Fallopian tube stem cells (FTSCs). We demonstrated that pedigrees of FTSCs were capable of multipotent differentiation and that the tumours derived from transformed FTSCs shared the histological and molecular features of HGSC. We also demonstrated that altered expression of some biomarkers seen in transformed FTSCs and HGSCs (stathmin, EZH2, CXCR4, CXCL12, and FOXM1) could be seen as well in immortalized cells and their in vivo counterparts SCOUTs and STINs. Thus, a whole-genome transcriptome analysis comparing FTSCs, immortalized FTSCs, and transformed FTSCs showed a clear molecular progression sequence that is recapitulated by the spectrum of accumulated perturbations characterizing the range of proliferations seen in vivo. Biomarkers unique to STIC relative to normal tubal epithelium provide a basis for novel detection approaches to early HGSC, but must be viewed critically given their potential expression in lesser proliferations. Perturbations shared by both immortalized and transformed FTSCs may provide unique early targets for prevention strategies. Central to these efforts has been the ability to clone and perpetuate multipotent FTSCs.

Rethinking ovarian cancer II: reducing mortality from high-grade serous ovarian cancer

High-grade serous ovarian cancer (HGSOC) accounts for 70-80% of ovarian cancer deaths, and overall survival has not changed significantly for several decades. In this Opinion article, we outline a set of research priorities that we believe will reduce incidence and improve outcomes for women with this disease. This 'roadmap' for HGSOC was determined after extensive discussions at an Ovarian Cancer Action meeting in January 2015.

Rethinking ovarian cancer II: reducing mortality from high-grade serous ovarian cancer

High-grade serous ovarian cancer (HGSOC) accounts for 70-80% of ovarian cancer deaths, and overall survival has not changed significantly for several decades. In this Opinion article, we outline a set of research priorities that we believe will reduce incidence and improve outcomes for women with this disease. This 'roadmap' for HGSOC was determined after extensive discussions at an Ovarian Cancer Action meeting in January 2015.

Rethinking ovarian cancer II: reducing mortality from high-grade serous ovarian cancer

High-grade serous ovarian cancer (HGSOC) accounts for 70-80% of ovarian cancer deaths, and overall survival has not changed significantly for several decades. In this Opinion article, we outline a set of research priorities that we believe will reduce incidence and improve outcomes for women with this disease. This 'roadmap' for HGSOC was determined after extensive discussions at an Ovarian Cancer Action meeting in January 2015.

Elevated STMN1 Expression Correlates with Poor Prognosis in Patients with Pancreatic Ductal Adenocarcinoma

STMN1 is a cytosolic phosphoprotein that not only participates in cell division, but also plays an important role in other microtubule-dependent processes, such as cell motility. Furthermore, STMN1 acts as a "relay protein" in several intracellular signaling pathways that influence cell growth and differentiation. Thus, STMN1 is likely to support cellular processes essential for tumor progression: survival and migration. Indeed, elevated STMN1 expression has been reported in various types of human malignancies and is correlated with poor prognosis in these human malignancies. However, the clinical and prognostic significance of STMN1 in pancreatic ductal adenocarcinoma (PDAC) remains unknown. Thus, we assessed STMN1 in PDAC in this retrospective study. We first examined STMN1 expression in PDAC tissues from 27 cases and matched adjacent non-cancerous tissues by quantitative polymerase chain reaction (PCR) and western blot analyses. Next, immunohistochemistry was used to evaluate STMN1 expression in 87 archived paraffin-embedded PDAC specimens. STMN1 mRNA and protein expression levels were to a large extent up-regulated in PDAC tissue compared with their adjacent non-cancerous tissues. Moreover, STMN1 expression was closely correlated with histological differentiation, lymphatic metastasis, and TNM stage (P = 0.023, 0.047, and 0.014, respectively). In addition, PDAC patients with higher STMN1 expression died sooner than those with lower STMN1 expression (P < 0.01). Multivariate analysis demonstrated that STMN1 expression was an independent prognostic factor for PDAC patients (P < 0.01). Herein, we provide the first evidence that up-regulated STMN1 may contribute to tumor progression and poor prognosis in PDAC patients and may serve as a novel prognostic marker.

Stathmin 1 and p16(INK4A) are sensitive adjunct biomarkers for serous tubal intraepithelial carcinoma

OBJECTIVE

To credential Stathmin 1 (STMN1) and p16(INK4A) (p16) as adjunct markers for the diagnosis of serous tubal intraepithelial carcinoma (STIC), and to compare STMN1 and p16 expression in p53-positive and p53-negative STIC and invasive high-grade serous carcinoma (HGSC).

METHODS

Immunohistochemistry (IHC) was used to examine STMN1 and p16 expression in fallopian tube specimens (n=31) containing p53-positive and p53-negative STICs, invasive HGSCs, and morphologically normal FTE (fallopian tube epithelium). STMN1 and p16 expression was scored semiquantitatively by four individuals. The semiquantitative scores were dichotomized, and reported as positive or negative. Pooled siRNA was used to knockdown p53 in a panel of cell lines derived from immortalized FTE and HGSC.

RESULTS

STMN1 and p16 were expressed in the majority of p53-positive and p53-negative STICs and concomitant invasive HGSCs, but only scattered positive cells were present in morphologically normal FTE. Both proteins were expressed consistently across multiple STICs from the same patient and in concomitant invasive HGSC. Knockdown of p53 in immortalized FTE cells and in four HGSC-derived cell lines expressing different missense p53 mutations did not affect STMN1 protein levels.

CONCLUSIONS

This study demonstrates that STMN1 and p16 are sensitive and specific adjunct biomarkers that, when used with p53 and Ki-67, improve the diagnostic accuracy of STIC. The addition of STMN1 and p16 helps to compensate for practical limitations of p53 and Ki-67 that complicate the diagnosis in up to one third of STICs.

STMN1 overexpression correlates with biological behavior in human cutaneous squamous cell carcinoma

Stathmin 1 (STMN1) is an important molecule in regulating cellular microtubule dynamics and promoting microtubule depolymerization in interphase and late mitosis. Evidences showed that STMN1 was up-regulated in many cancers, but there was no report about the roles of STMN1 in human cutaneous squamous cell carcinoma (cSCC). Here, we confirmed significant upregulation of STMN1 in cSCC tissues and cell lines compared with non-tumor counterparts. STMN1 upregulation was associated with the proliferation, migration, invasion and apoptosis of cSCC cells. The results suggested that STMN1 may play an important role in the development and tumor progression of cSCC.

Immunohistochemical panel to differentiate endometrial stromal sarcoma, uterine leiomyosarcoma and leiomyoma: something old and something new

AIMS

To evaluate an immunohistochemical panel differentiating endometrial stromal sarcoma (ESS) from uterine leiomyosarcoma (ULMS) and leiomyoma (LM).

METHODS

94 cases (28 ESS, 41 ULMS, 25 LM) were retrieved and arrayed. 10 immunomarkers (estrogen receptor (ER), progesterone receptor (PR), CD10, smooth muscle actin, desmin, h-caldesmon, transgelin, GEM, ASC1, stathmin1) were used. A predictive model was constructed and examined by receiver operating characteristics curve analysis to determine area under the curve (AUC).

RESULTS

The combination of ER(+)/PR(+)/CD10(+)/GEM(-)/h-caldesmon(-)/transgelin(-) can predict ESS versus ULMS with AUC predictive value of 0.872 (95% CI 0.784 to 0.961, p<0.0001). The combination of ER(+)/PR(+)/CD10(+)/h-caldesmon(-)/transgelin(-) can predict low grade (LG) ESS from 'LG' ULMS with AUC predictive value of 0.914 (95% CI 0.832 to 0.995, p<0.0001). Finally, ULMS and ESS, including the LGs, were more likely to be stathmin1(+) than LM.

CONCLUSIONS

Due to the different clinical course and management, adding novel antibodies (GEM, transgelin) to the well established immunohistochemistry panel seemed to be useful in distinguishing ESS from ULMS and LG ESS from 'LG' ULMS. Finally, stathmin1 expression could be of value in differentiating LM from uterine sarcomas.

An immunohistochemical analysis of stathmin 1 expression in uterine smooth muscle tumors: differential expression in leiomyosarcomas and leiomyomas

The oncogenic phosphatidylinositol 3-kinase-AKT-mammlian target of rapamycin pathway (PI3K-AKT-mTOR) pathway is known to be activated in uterine smooth muscle tumors, and Stathmin 1 (STMN1) expression has been identified as a marker of PI3K-AKT-mTOR pathway activation. We hypothesized that STMN1 may have some diagnostic utility and explored how well STMN1 expression correlated with histologic classifications of uterine smooth muscle tumors into benign and malignant groupings. 84 smooth muscle tumors were assessed for STMN1 expression by immunohistochemistry. These included spindle cell leiomyosarcoma (n=32), conventional spindle cell leiomyomas (n=30), atypical (symplastic) leiomyoma (n=5), cellular leiomyoma (n=7), smooth muscle tumor of uncertain malignant potential (n=4), mitotically active leiomyomas (n=2), benign metastasizing leiomyoma (n=3), and cotyledonoid dissecting leiomyoma (n=1). All spindle cell leiomyosarcomas were positive (32/32 positive; 100%) as compared with conventional leiomyomata (11/30; 37%) (P<0.0001). The average immunohistochemical score (0-12+, reflective of intensity and extent) for leiomyosarcomas was 8.7 (±1.43) whereas the conventional leiomyomata average score was 1.6 (±1.07) (P<0.0001). This difference in scores was reflected in the patterns of expression: leiomyosarcomas were predominantly strongly and diffusely positive whereas leiomyomata were predominantly weakly, albeit diffusely positive when expression was present. The sensitivity of STMN1 expression for leiomyosarcomas was 100%. However, the specificity was found to be only 55% (CI=43-68%). The negative and positive predictive values for leiomyosarcomas were 100% and 52% respectively. The odds ratio (OR) for any STMN1 expression in predicting a spindle cell leiomyosarcoma diagnosis from this dataset was highly significant (OR=144, P=0.0006). Thirteen non-smooth muscle tumors that involved the uterus all showed at least focal STMN1 immunoreactivity. In summary, STMN1 is a highly sensitive marker for leiomyosarcoma but is suboptimally specific for diagnostic purposes. The 100% negative predictive value for leiomyosarcoma may offer some diagnostic utility in a small sample, since the absence of STMN1 immunoreactivity in a putative leiomyosarcoma is a strong argument against this diagnostic possibility.

[Prophylactic salpingectomy or salpingo-oophorectomy as an ovarian cancer prevention?]

A recent hypothesis has stated that many ovarian cancers (especially high-grade serous histotype) could arise from the distal part of the fallopian tube. On one hand we know that risk-reducing salpingo-oophorectomy is the most effective prevention for ovarian cancer among BRCA mutation carriers. On the other, oophorectomy increases the relative risk for cardiovascular, osteoporotic psychosexual and cognitive dysfunctions in premenopausal women. This raises the question whether bilateral salpingectomy could be an effective strategy in the prevention of ovarian cancer in case of hereditary predisposition and in the general population. Here we discuss origin of ovarian cancer in the light of the latest molecular studies and the relative risks and benefits of a strategy of exclusive salpingectomy in comparison with the classical adnexectomy.

Silencing stathmin-modulating efficiency of chemotherapy for esophageal squamous cell cancer with paclitaxel

Paclitaxel (PTX) is broadly considered the drug of choice for treating human esophageal squamous cell cancer (ESCC). However, PTX resistance often ultimately leads to treatment failure. stathmin, or Op18, is a ubiquitously expressed 19-kDa cytosolic phosphoprotein that can integrate various cellular regulatory signals. stathmin overexpression could lead to resistance to chemotherapeutic agents. In this study we investigated the effect of stathmin gene silencing, using small interfering RNA (stathmin siRNA), on the efficacy of PTX in ESCC. Transfection of stathmin siRNA could significantly inhibit stathmin mRNA and protein levels in ESCC cell lines EC9706 and Eca-109. The silencing of stathmin combined with PTX significantly inhibited the proliferation of EC9706 and Eca-109 cells, with a significantly higher proportion of cells at G2/M phase and this antiproliferative effect was accompanied by an increase in apoptosis rates and morphology changes of EC9706 and Eca-109. Thus, combined chemotherapeutic agent PTX and stathmin siRNA could potentially enhance the therapeutic outcomes of PTX in treating ESCC.

Stathmin is a marker of progression and poor prognosis in esophageal carcinoma

Stathmin, also called oncoprotein 18, is a founding member of the family of microtubule-destabilizing proteins that play a critical role in the regulation of mitosis. At the same time stathmin has been recognized as one of responsible factors in cancer cells. The aim of this study was to assess stathmin status, its correlations with clinicopathological parameters and its role as a progosnostic marker in EC patients. The protein and mRNA levels of stathmin were examined by immunohistochemistry (IHC) and in situ hybridization in 100EC tissues and adjacent noncancerous tissues. mRNA and protein expression of stathmin in three EC cell lines(EC9706, ECa109, EC1 commonly used in research) were also analyzed using immunocytochemistry, western blot and in situ hybridization. The prognostic value of Stathmin expression within the tumor tissues were assessed by Cox regression and Kaplan-Meier analysis. We showed that stathmin expression was significantly higher in EC tissues than in adjacent noncancerous tissues. High stathmin immunostaining score in the EC was positively correlated with tumor differentiation, Tumor invasion, Lymph node metastases, and TNM stage. In addition, we demonstrated that three EC cell lines examined, were constitutively expressing a high level of stathmin. Of those, EC-1 showed the strongest mRNA and protein expression for the stathmin analyzed. Kaplan-Meier analysis showed that significantly longer 5-year survival rate was seen in EC patients with high Stathmin expression, compared to those with low expression of Stathmin expression. Furthermore, multivariate Cox proportional hazard analyses revealed that Stathmin was an independent factors affecting the overall survival probability. In conclusion, our data provide a basis for the concept that stathmin might be associated with EC development and progression.. High levels of Stathmin expression in the tumor tissues may be a good prognostic marker for patients with EC.

The PAX2-null immunophenotype defines multiple lineages with common expression signatures in benign and neoplastic oviductal epithelium

The oviducts contain high-grade serous cancer (HGSC) precursors (serous tubal intraepithelial neoplasia or STINs), which are γ-H2AX(p) - and TP53 mutation-positive. Although they express wild-type p53, secretory cell outgrowths (SCOUTs) are associated with older age and serous cancer; moreover, both STINs and SCOUTs share a loss of PAX2 expression (PAX2(n) ). We evaluated PAX2 expression in proliferating adult and embryonic oviductal cells, normal mucosa, SCOUTs, Walthard cell nests (WCNs), STINs, and HGSCs, and the expression of genes chosen empirically or from SCOUT expression arrays. Clones generated in vitro from embryonic gynaecological tract and adult Fallopian tube were Krt7(p) /PAX2(n) /EZH2(p) and underwent ciliated (PAX2(n) /EZH2(n) /FOXJ1(p) ) and basal (Krt7(n) /EZH2(n) /Krt5(p) ) differentiation. Similarly, non-ciliated cells in normal mucosa were PAX2(p) but became PAX2(n) in multi-layered epithelium undergoing ciliated or basal (WCN) cell differentiation. PAX2(n) SCOUTs fell into two groups: type 1 were secretory or secretory/ciliated with a 'tubal' phenotype and were ALDH1(n) and β-catenin(mem) (membraneous only). Type 2 displayed a columnar to pseudostratified (endometrioid) phenotype, with an EZH2(p) , ALDH1(p) , β-catenin(nc) (nuclear and cytoplasmic), stathmin(p) , LEF1(p) , RCN1(p) , and RUNX2(p) expression signature. STINs and HGSCs shared the type 1 immunophenotype of PAX2(n) , ALDH1(n) , β-catenin(mem) , but highly expressed EZH2(p) , LEF1(p) , RCN1(p) , and stathmin(p) . This study, for the first time, links PAX2(n) with proliferating fetal and adult oviductal cells undergoing basal and ciliated differentiation and shows that this expression state is maintained in SCOUTs, STINs, and HGSCs. All three entities can demonstrate a consistent perturbation of genes involved in potential tumour suppressor gene silencing (EZH2), transcriptional regulation (LEF1), regulation of differentiation (RUNX2), calcium binding (RCN1), and oncogenesis (stathmin). This shared expression signature between benign and neoplastic entities links normal progenitor cell expansion to abnormal and neoplastic outgrowth in the oviduct and exposes a common pathway that could be a target for early prevention.