Expression of the oncofetal protein IGF2BP3 in endometrial clear cell carcinoma: assessment of frequency and significance

RNA modification regulators as promising biomarkers in gynecological cancers

This review explores the evolving landscape of gynecological oncology by focusing on emerging RNA modification signatures as promising biomarkers for assessing the risk and progression of ovarian, cervical, and uterine cancers. It provides a comprehensive overview of common RNA modifications, especially m6A, and their roles in cellular processes, emphasizing their implications in gynecological cancer development. The review meticulously examines specific m6A regulators including "writers", "readers", and "erasers" associated with three gynecological cancer types, discussing their involvement in initiation and progression. Methodologies for detecting RNA modifications are surveyed, highlighting advancements in high-throughput techniques with high sensitivity. A critical analysis of studies identifying m6A regulators as potential biomarkers is presented, addressing their diagnostic or prognostic significance. Mechanistic insights into RNA modification-mediated cancer progression are explored, shedding light on molecular pathways and potential therapeutic targets. Despite current challenges, the review discusses ongoing research efforts, future directions, and the transformative possibility of RNA modifications on early assessment and personalized therapy in gynecological oncology.

Association of insulin-like growth factor II mrna-binding protein 3 (IMP3) expression with prognostic and morphological factors in endometrial cancer

Objective

Endometrial cancer (EC) is a heterogeneous disease with recurrence rates ranging from 15 to 20%. The discrimination of cases with a worse prognosis aims, in part, to reduce the length of surgical staging in cases with a better prognosis. This study aimed to evaluate the association between Insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression and prognostic and morphological factors in EC.

Methods

This retrospective, cross-sectional, analytical study included 79 EC patients - 70 endometrioid carcinoma (EEC) and 9 serous carcinoma (SC) - and 74 benign endometrium controls. IMP3 expression was evaluated by immunohistochemistry-based TMA (Tissue Microarray), and the results were associated with morphological and prognostic factors, including claudins 3 and 4, estrogen and progesterone receptors, TP53, and KI67.

Results

IMP3 expression was significantly higher in SC compared to EEC in both extent (p<0.001) and intensity (p=0.044). It was also significantly associated with worse prognostic factors, including degree of differentiation (p=0.024, p<0.001), staging (p<0.001; p<0.001) and metastasis (p=0.002; p<0.001). IMP3 expression was also significant in extent (p=0.002) in endometrial tumors compared with controls. In addition, protein TP53 and KI67 showed significant associations in extent and intensity, respectively.

Conclusion

IMP3 expression was associated with worse prognostic factors studied. These findings suggest that IMP3 may be a potential biomarker for EC poorer prognosis.

Genome instability-derived genes as a novel prognostic signature for lung adenocarcinoma

Background: An increasing number of patients are being diagnosed with lung adenocarcinoma, but there remains limited progress in enhancing prognostic outcomes and improving survival rates for these patients. Genome instability is considered a contributing factor, as it enables other hallmarks of cancer to acquire functional capabilities, thus allowing cancer cells to survive, proliferate, and disseminate. Despite the importance of genome instability in cancer development, few studies have explored the prognostic signature associated with genome instability for lung adenocarcinoma. Methods: In the study, we randomly divided 397 lung adenocarcinoma patients from The Cancer Genome Atlas database into a training group (n = 199) and a testing group (n = 198). By calculating the cumulative counts of genomic alterations for each patient in the training group, we distinguished the top 25% and bottom 25% of patients. We then compared their gene expressions to identify genome instability-related genes. Next, we used univariate and multivariate Cox regression analyses to identify the prognostic signature. We also performed the Kaplan-Meier survival analysis and the log-rank test to evaluate the performance of the identified prognostic signature. The performance of the signature was further validated in the testing group, in The Cancer Genome Atlas dataset, and in external datasets. We also conducted a time-dependent receiver operating characteristic analysis to compare our signature with established prognostic signatures to demonstrate its potential clinical value. Results: We identified GULPsig, which includes IGF2BP1, IGF2BP3, SMC1B, CLDN6, and LY6K, as a prognostic signature for lung adenocarcinoma patients from 42 genome instability-related genes. Based on the risk score of the risk model with GULPsig, we successfully stratified the patients into high- and low-risk groups according to the results of the Kaplan-Meier survival analysis and the log-rank test. We further validated the performance of GULPsig as an independent prognostic signature and observed that it outperformed established prognostic signatures. Conclusion: We provided new insights to explore the clinical application of genome instability and identified GULPsig as a potential prognostic signature for lung adenocarcinoma patients.

A comprehensive immunohistochemical analysis of IMP2 and IMP3 in 542 cases of ovarian tumors

BACKGROUND

IMP2 and IMP3 are mRNA binding proteins involved in carcinogenesis. We examined a large cohort of ovarian tumors with the aim to assess the value of IMP2 and IMP3 for differential diagnosis, and to assess their prognostic significance.

METHODS

Immunohistochemical analyses with antibodies against IMP2 and IMP3 were performed on 554 primary ovarian tumors including 114 high grade serous carcinomas, 100 low grade serous carcinomas, 124 clear cell carcinomas, 54 endometrioid carcinomas, 34 mucinous carcinomas, 75 mucinous borderline tumors, and 41 serous borderline tumors (micropapillary variant). The associations of overall positivity with clinicopathological characteristics were evaluated using the chi-squared test or Fisher's Exact test.

RESULTS

We found IMP2 expression (in more than 5% of tumor cells) in nearly all cases of all tumor types, so the prognostic meaning could not be analyzed. The positive IMP3 expression (in more than 5% of tumor cells) was most common in mucinous carcinomas (82%) and mucinous borderline tumors (81%), followed by high grade serous (67%) and clear cell carcinomas (67%). The expression was less frequent in endometrioid carcinomas (39%), low grade serous carcinomas (23%), and micropapillary variant of serous borderline tumors (20%). Prognostic significance of IMP3 could be evaluated only in low grade serous carcinomas in the case of relapse-free survival, where negative cases showed better RFS (p = 0.033).

CONCLUSION

Concerning differential diagnosis our results imply that despite the differences in expression in the different ovarian tumor types, the practical value for diagnostic purposes is limited. Contrary to other solid tumors, we did not find prognostic significance of IMP3 in ovarian cancer, with the exception of RFS in low grade serous carcinomas. However, the high expression of IMP2 and IMP3 could be of predictive value in ovarian carcinomas since IMP proteins are potential therapeutical targets.

Immunohistochemical comparative analysis of IMP-3 and KI-67 in actinic cheilitis and lower lip squamous cell carcinoma

Actinic cheilitis (AC) and lower lip squamous cell carcinoma (LLSCC) exhibit epithelial alterations mainly associated with chronic ultraviolet ray exposure. Currently, it is impossible to predict which AC cases will progress to LLSCC; thus, biomolecular markers have been studied. The aim of this study was to evaluate the immunoexpression of IMP-3 and KI-67 in AC and LLSCC. Forty AC and 40 LLSCC cases were submitted to peroxidase method and quantitatively analyzed, using the following scores: 0 (0% positive cells), + 1(≤ 30%), + 2 (> 30% to ≤ 60%), and + 3 (> 60%). Results were submitted to non-parametric Mann-Whitney (U) test. A p value < 0.05 was considered to indicate statistical significance. IMP-3 immunoexpression was observed in 26 AC cases, with predominance of the score 1 (35% of cases). This protein was also positive in 22 LLSCC cases, with predominance of the score 3 (37.5% of cases). Immunoexpression of KI-67 was observed in all studied cases, with predominance of the score 2 (70% of AC cases and 57.5% LLSCC cases). The association between IMP-3 and Ki-67 immunoexpression, AC dysplastic severity and LLSCC tumoral grade revealed no significant differences. The present results demonstrate that IMP-3 and Ki-67 immunoexpression are frequent in AC and in LLSCC. Moreover, these proteins could be involved in lower lip carcinogenesis process.

IGF2BP3 enhances the mRNA stability of E2F3 by interacting with LINC00958 to promote endometrial carcinoma progression

Long noncoding RNAs (lncRNAs) play important regulatory roles in a variety of pathological processes involving cancer. However, the exact molecular mechanisms of lncRNA regulation in endometrial carcinoma (EC) remain poorly defined. The aim of this study was to illustrate the mechanism of LINC00958 in regulating the function of IGF2BP3, an RNA binding protein involved in mRNA stability, and their clinical implications in EC. First, we investigated the clinical role of IGF2BP3 in EC and demonstrated its prognostic value. Loss-of-function and gain-of-function studies showed that IGF2BP3 promoted EC cell proliferation, migration and invasion. Then, we carried out RNA immunoprecipitation sequencing (RIP-seq) analysis, RNA pulldown and immunofluorescence-RNA fluorescence in situ hybridization to identify LINC00958 that interacted with IGF2BP3 in the cytoplasm of EC cells. Rescue experiments indicated that knockdown of LINC00958 partially offset the EC cell progression mediated by IGF2BP3. After that, RNA sequencing was used to screen out the downstream genes of IGF2BP3 and LINC00958. The results revealed that IGF2BP3 upregulated E2F3 expression by interacting with LINC00958. Furthermore, RNA stability assays demonstrated that silencing LINC00958 partially rescued the IGF2BP3-mediated promoting effect on the mRNA stability of E2F3. Collectively, this study suggests that LINC00958, as an oncogene, assists IGF2BP3 in stabilizing E2F3 mRNA and ultimately promotes EC progression, providing a promising therapeutic target for patients with EC.

Immunohistochemical Study of IMP3 Expression in Laryngeal Squamous Cell Carcinoma

BACKGROUND: IMP3 is an RNA binding protein, which is strongly expressed in malignant tumors, promoting tumor cell proliferation. AIM: The aim of the study was to evaluate the expression of IMP3 in laryngeal squamous cell carcinoma (SCC) and to correlate the expression of IMP3 with available clinicopathological data. METHODS: Sixty one total laryngectomy and laryngoscopic biopsies; collected from the Pathology Department, Faculty of Medicine, Cairo University. Two slides were prepared from each paraffin embedded tumor block, one slide for Hematoxylin and Eosin staining, and the other for immunohistochemical staining by IMP3 polyclonal antibody. RESULTS: Thirty-seven cases (60.7%) showed positive IMP3 expression, and a statistically significant correlation was found between IMP3 expressions in normal, dysplastic epithelium/in situ component, and the invasive malignant tumor tissue. Correlations between IMP3 expression and other available clinicopathological data were all non-significant. CONCLUSION: This study suggests that IMP3 might play a role in laryngeal SCC carcinogenesis and progression process from normal to dysplastic to malignant epithelium, and thus IMP3 might be targeted by gene therapy.

Development and validation of m6A regulators' prognostic significance for endometrial cancer

BACKGROUND

Endometrial cancer (EC) is the sixth most common cancer in women globally. It has been found that the expression levels of m6A regulators can be potentially used for prognostic stratification in some cancers, but the role of m6A regulators in EC prognosis remains unclear.

METHODS

The data of 584 EC samples were downloaded from The Cancer Genome Atlas and the mRNA expression profiles of 20 m6A regulators were analyzed, followed by functional enrichment analysis, immune infiltration analysis, and least absolute shrinkage and selection operator method-COX regression analysis.

RESULTS

The mRNA expression levels of 20 m6A regulators were significantly different between cancer samples across different grades. The 548 EC samples could be clearly divided into 2 clusters. Kaplan-Meier survival analysis proved that these two groups had highly different overall survival probabilities. Besides, the univariate regression analysis further reserved eight genes related to overall survival from the 20 m6A regulators. We established a prognostic signature including two genes, that is, IGF2BP1 and YTHDF3, that showed a strong ability for stratifying prognostically different EC patients. We identified 3239 differentially expressed genes between the high- and low-risk groups, involving in multiple biological processes and signaling pathways. Meanwhile, 6 differentially infiltrated immune cell types between the high- and low-risk groups could effectively distinguish the high- and low-risk EC groups. The expressions of immune checkpoints were different between high- and low-risk EC patients.

CONCLUSION

We first report the prognostic role of m6A regulators in EC, which should contribute to a better understanding of the underlying mechanisms of EC pathogenesis and progression.

RNA-binding protein IMP3 is a novel regulator of MEK1/ERK signaling pathway in the progression of colorectal Cancer through the stabilization of MEKK1 mRNA

Background

MEK1/ERK signaling pathway plays an important role in most tumor progression, including colorectal cancer (CRC), however, MEK1-targeting therapy has little effective in treating CRC patients, indicating there may be a complex mechanism to activate MEK1/ERK signaling pathway except RAS activated mechanism.

Methods

To investigate the clinical significance of IMP3, we analyzed its expression levels in publicly available dataset and samples from Fudan University Shanghai Cancer Center. The effects of IMP3 on proliferation, migration, and invasion were determined by in vitro and in vivo experiments. To investigate the role of IMP3 in colon carcinogenesis, conditional IMP3 knockout C57BL/6 mice was generated. The IMP3/MEKK1/MEK/ERK signaling axis in CRC was screened and validated by RNA-sequencing, RNA immunoprecipitation, luciferase reporter and western blot assays.

Results

We find RNA binding protein IMP3 directly bind to MEKK1 mRNA 3′-UTR, which regulates its stability, promote MEKK1 expression and sequentially activates MEK1/ERK signaling. Functionally, IMP3 promote the malignant biological process of CRC cells via MEKK1/MEK1/ERK signaling pathway both in vitro and in vivo, Moreover, IMP3^−/− mice show decreased the expression of MEKK1 as well as colorectal tumors compared with wild-type mice after treatment with azoxymethane/dextran sodium sulfate. Clinically, the expression of IMP3 and MEKK1 are positive correlated, and concomitant IMP3 and MEKK1 protein levels negatively correlate with metastasis in CRC patients. In addition, MEK1 inhibitor in combination with shRNA-IMP3 have a synergistic effect both in vitro and in vivo.

Conclusion

Our study demonstrates that IMP3 regulates MEKK1 in CRC, thus activating the MEK1/ERK signaling in the progression of colorectal cancer, Furthermore, these results provide new insights into potential applications for combining MEK1 inhibitors with other target therapy such as IMP3 in preclinical trials for CRC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01994-8.

CCNE1 and BRD4 co-amplification in high-grade serous ovarian cancer is associated with poor clinical outcomes

OBJECTIVE

High-grade serous ovarian cancer (HGSOC) is the most common and lethal histological subtype of epithelial ovarian cancer. HGSOC with cyclin E1 gene (CCNE1) amplification and bromodomain and extraterminal 4 (BRD4) amplification have been associated with poor outcomes. Our objective was to evaluate clinical outcomes of HGSOC with co-amplification of CCNE1 and BRD4 and high protein expression of cyclin E and BRD4.

METHODS

Copy number amplification data were extracted from The Cancer Genome Atlas (TCGA) for 579 HGSOC. Reverse phase protein array (RPPA) TCGA data were used to determine cyclin E and BRD4 protein expression in 482 HGSOC. Cyclin E and BRD4 protein expression by immunohistochemistry (IHC) was evaluated in a tissue microarray (TMA) of 110 HGSOC. Measured clinical outcomes were survival and platinum sensitivity.

RESULTS

Of 30% of HGSOC with amplifications in CCNE1 or BRD4, 8% have both CCNE1 and BRD4 amplification. Protein expression of cyclin E and BRD4 are positively correlated, both by RPPA (r = 0.23; p < 0.001) and by IHC (r = 0.21; p = 0.025). Patients with CCNE1 and BRD4 co-amplified HGSOC have worse overall survival than patients without amplifications, 39.94 vs 48.06 months (p = 0.029). High protein expression of cyclin E, but not BRD4, was associated with poor overall survival (HR 1.62, 1.04-2.53, p = 0.033) and platinum resistance (p = 0.016).

CONCLUSION

HGSOC with CCNE1 and BRD4 co-amplification are associated with poor overall survival. Further studies are warranted to determine the use of protein expression by IHC as a surrogate marker for CCNE1 and BRD4 co-amplified HGSOC.

High-grade Endometrial Carcinomas: Morphologic and Immunohistochemical Features, Diagnostic Challenges and Recommendations

This review of challenging diagnostic issues concerning high-grade endometrial carcinomas is derived from the authors' review of the literature followed by discussions at the Endometrial Cancer Workshop sponsored by the International Society of Gynecological Pathologists in 2016. Recommendations presented are evidence-based, insofar as this is possible, given that the levels of evidence are weak or moderate due to small sample sizes and nonuniform diagnostic criteria used in many studies. High-grade endometrioid carcinomas include FIGO grade 3 endometrioid carcinomas, serous carcinomas, clear cell carcinomas, undifferentiated carcinomas, and carcinosarcomas. FIGO grade 3 endometrioid carcinoma is diagnosed when an endometrioid carcinoma exhibits >50% solid architecture (excluding squamous areas), or when an architecturally FIGO grade 2 endometrioid carcinoma exhibits marked cytologic atypia, provided that a glandular variant of serous carcinoma has been excluded. The most useful immunohistochemical studies to make the distinction between these 2 histotypes are p53, p16, DNA mismatch repair proteins, PTEN, and ARID1A. Endometrial clear cell carcinomas must display prototypical architectural and cytologic features for diagnosis. Immunohistochemical stains, including, Napsin A and p504s can be used as ancillary diagnostic tools; p53 expression is aberrant in a minority of clear cell carcinomas. Of note, clear cells are found in all types of high-grade endometrial carcinomas, leading to a tendency to overdiagnose clear cell carcinoma. Undifferentiated carcinoma (which when associated with a component of low-grade endometrioid carcinoma is termed "dedifferentiated carcinoma") is composed of sheets of monotonous, typically dyscohesive cells, which can have a rhabdoid appearance; they often exhibit limited expression of cytokeratins and epithelial membrane antigen, are usually negative for PAX8 and hormone receptors, lack membranous e-cadherin and commonly demonstrate loss of expression of DNA mismatch repair proteins and SWI-SNF chromatin remodeling proteins. Carcinosarcomas must show unequivocal morphologic evidence of malignant epithelial and mesenchymal differentiation.

The expression of IMP3 in 366 cases with ovarian carcinoma of high grade serous, endometrioid and clear cell subtypes

The clear cell (CCC), high grade serous (HGSC) and endometrioid (EC) ovarian carcinomas share overlapping histological features. The oncogene IMP3 is implicated in CCC with an elusive utility in differential diagnosis. We collected 366 cases with ovarian primary carcinomas to detect IMP3, Napsin-A and HNF-1β by immunochemistry. In 351 cases, the positive expression rate of IMP3 in CCC was significantly higher than that either in EC or HGSC (p < 0.01). The sensitivity of IMP3 in CCC was higher than Napsin-A but lower than HNF-1β (p < 0.01). The specificity of IMP3 in CCC was lower than Napsin-A but higher than HNF-1β (p < 0.01). The composite markers Napsin-A+/IMP3+ and the IMP3+/HNF-1β+/Napsin-A+ offered the highest odds ratio (p < 0.001), the highest specificity, the highest positive predictive value and the highest positive likelihood ratio. The ROC analysis showed that the combination of Napsin-A, HNF-1β and IMP3 offered the biggest AUC compared with either the singular marker performances or the other binary combinations (p < 0.001). In 15 cases of EC mixed with CCC, IMP3 showed a better discrimination value than the other two markers. Consequently, adding IMP3 to the diagnostic panel might provide some help with the pathological diagnosis of ovarian CCC.

Translational Dysregulation in Cancer: Molecular Insights and Potential Clinical Applications in Biomarker Development

Although transcript levels have been traditionally used as a surrogate measure of gene expression, it is increasingly recognized that the latter is extensively and dynamically modulated at the level of translation (messenger RNA to protein). Over the recent years, significant progress has been made in dissecting the complex posttranscriptional mechanisms that regulate gene expression. This advancement in knowledge came hand in hand with the progress made in the methodologies to study translation both at gene-specific as well as global genomic level. The majority of translational control is exerted at the level of initiation; nonetheless, protein synthesis can be modulated at the level of translation elongation, termination, and recycling. Sequence and structural elements and epitranscriptomic modifications of individual transcripts allow for dynamic gene-specific modulation of translation. Cancer cells usurp the regulatory mechanisms that govern translation to carry out translational programs that lead to the phenotypic hallmarks of cancer. Translation is a critical nexus in neoplastic transformation. Multiple oncogenes and signaling pathways that are activated, upregulated, or mutated in cancer converge on translation and their transformative impact "bottlenecks" at the level of translation. Moreover, this translational dysregulation allows cancer cells to adapt to a diverse array of stresses associated with a hostile microenviroment and antitumor therapies. All elements involved in the process of translation, from the transcriptional template, the components of the translational machinery, to the proteins that interact with the transcriptome, have been found to be qualitatively and/or quantitatively perturbed in cancer. This review discusses the regulatory mechanisms that govern translation in normal cells and how translation becomes dysregulated in cancer leading to the phenotypic hallmarks of malignancy. We also discuss how dysregulated mediators or components of translation can be utilized as biomarkers with potential diagnostic, prognostic, or predictive significance. Such biomarkers have the potential advantage of uniform applicability in the face of inherent tumor heterogeneity and deoxyribonucleic acid instability. As translation becomes increasingly recognized as a process gone awry in cancer and agents are developed to target it, the utility and significance of these potential biomarkers is expected to increase.

Expression profile, clinical significance, and biological function of insulin-like growth factor 2 messenger RNA-binding proteins in non–small cell lung cancer

Insulin-like growth factor 2 messenger RNA-binding proteins have been described to associate with malignant process in many cancers. However, the role of insulin-like growth factor 2 messenger RNA-binding protein family has not been thoroughly elucidated in non–small cell lung cancer. This study was to investigate the expression profile, clinical significance, and biological function of insulin-like growth factor 2 messenger RNA-binding proteins family in non–small cell lung cancer. The expression levels of IGF2BP1–IGF2BP3 in tumor and adjacent normal tissues were determined, and association with clinicopathological features and overall survival was investigated by analyzing The Cancer Genome Atlas lung cancer database. Proliferation, migration, invasion assays, and flow-cytometry analysis were used to investigate the biological function in vitro. Insulin-like growth factor 2 messenger RNA-binding protein expression levels were significantly increased in non–small cell lung cancer compared to adjacent normal lung tissues. Chi-square test indicated that IGF2BP1 and IGF2BP3 expressions correlated with some meaningful clinical characteristics in non–small cell lung cancer. Kaplan–Meier analysis showed that high-level expression of IGF2BP1 or IGF2BP3 predicted poor overall survival in lung adenocarcinoma patients. Multivariate regression analysis showed that high level of IGF2BP3 was an independent risk factor for poor prognosis in lung adenocarcinoma patients (hazard ratio = 1.616, p = 0.017). In vitro, knockdown of IGF2BP3 inhibited lung adenocarcinoma cell proliferation by inducing cell cycle arrest and apoptosis, and undermined abilities of migration and invasion, and overexpression of IGF2BP3 could promote malignant phenotypes in lung adenocarcinoma cells. Our study revealed that expression of insulin-like growth factor 2 messenger RNA-binding proteins was widely upregulated and correlated with some certain clinicopathological features in non–small cell lung cancer. Especially, in insulin-like growth factor 2 messenger RNA-binding protein family, IGF2BP3 might play the most important role in tumor aggressiveness and prognosis in lung adenocarcinoma, and IGF2BP3 might serve as a potential therapeutic target and a novel prognostic biomarker in lung adenocarcinoma patients.

Expression and utility of IMP3 in the differential diagnosis of atypical glandular cells and adenocarcinoma in liquid-based cervical cytology

BACKGROUND

Atypical glandular cell (AGC) interpretation in gynecological cytopathology presents many diagnostic challenges. We evaluated the expression of IMP3 in liquid-based cervical cytology and its utility in differentiating premalignant/malignant glandular lesions from benign/reactive processes. Additionally, we tried to determine whether IMP3 may be useful in differentiating among the types of uterine adenocarcinomas.

DESIGN

Our cohort included 82 cases; 59 diagnosed with AGC and 23 with adenocarcinoma (Ac). IMP3 immunocytochemical stain was performed on ThinPrep slides and the results correlated with subsequent biopsy findings. IMP3 positivity was assessed by strong (2+ and 3+) granular cytoplasmic staining in at least one group of three epithelial cells.

RESULTS

In the AGC group, IMP3 was positive in 14 (73.7%) of 19 cases that on histologic follow-up were confirmed Ac, and 39 (98.6%) of 40 non-glandular lesions/benign cases were negative. In the Ac group, IMP3 was expressed in 16 (69.6%) of 23 cases, of which 16 (72.2%) of 21 were uterine Ac. By combining the two groups, and excluding the 2 extrauterine carcinomas, IMP3 was positive in 30 (75%) of 40 uterine Ac, most of which (86.7%) were in situ/invasive endocervical Ac, and type II endometrial Ac (Papillary Serous and Clear Cell Carcinoma), and only 40% endometrioid Ac.

CONCLUSION

In ThinPrep slides with AGC, IMP3 positivity predicts the presence of a significant endocervical or endometrial lesion on subsequent histology, and may also be a potential diagnostic tool useful in differentiating among the types of adenocarcinomas of the female lower genital tract.

RNA-binding protein IGF2BP3 targeting of oncogenic transcripts promotes hematopoietic progenitor proliferation

Posttranscriptional control of gene expression is important for defining both normal and pathological cellular phenotypes. In vitro, RNA-binding proteins (RBPs) have recently been shown to play important roles in posttranscriptional regulation; however, the contribution of RBPs to cell specification is not well understood. Here, we determined that the RBP insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) is specifically overexpressed in mixed lineage leukemia-rearranged (MLL-rearranged) B-acute lymphoblastic leukemia (B-ALL), which constitutes a subtype of this malignancy associated with poor prognosis and high risk of relapse. IGF2BP3 was required for the survival of B-ALL cell lines, as knockdown led to decreased proliferation and increased apoptosis. Enforced expression of IGF2BP3 provided murine BM cells with a strong survival advantage, led to proliferation of hematopoietic stem and progenitor cells, and skewed hematopoietic development to the B cell/myeloid lineage. Cross-link immunoprecipitation and high throughput sequencing uncovered the IGF2BP3-regulated transcriptome, which includes oncogenes MYC and CDK6 as direct targets. IGF2BP3 regulated transcripts via targeting elements within 3' untranslated regions (3'UTR), and enforced IGF2BP3 expression in mice resulted in enhanced expression of Myc and Cdk6 in BM. Together, our data suggest that IGF2BP3-mediated targeting of oncogenic transcripts may represent a critical pathogenetic mechanism in MLL-rearranged B-ALL and support IGF2BP3 and its cognate RNA-binding partners as potential therapeutic targets in this disease.

Clear cell carcinomas of the ovary: a mono-institutional study of 73 cases in China with an analysis of the prognostic significance of clinicopathological parameters and IMP3 expression

Background

Ovarian clear cell carcinoma (CCC) is an uncommon subtype of ovarian epithelial tumor. The prognostic significance of its clinicopathological parameters is discordant, with the exception of stage as the adverse prognostic factor. The present study aimed to evaluate the prognostic significance of its clinicopathological characteristics and the expression of IMP3 (Insulin-like growth factor-II mRNA-binding protein 3, IMP3 or IGF2BP3) in Chinese patients with primary pure CCC.

Methods

We collected clinicopathological data from 73 cases with a minimum of 5 years of follow-up and evaluated the expression of IMP3 by immunohistochemistry.

Results

In total, 49.3 % of the patients were in stage I. Advanced stages were closely related to poor prognosis of disease-free survival (DFS) and overall survival (OS) (P < 0.005). Patients with CCC coexisting with endometriosis tended to be younger and to have unilateral involvement but did not exhibit differences in prognosis compared with patients with CCC without endometriosis. Other histological features such as growth pattern, mitosis, and necrosis did not have prognostic significance. IMP3 was positive in 63 % of patients (46 of 73 cases); Thus, positive expression of IMP3 is an adverse prognostic marker in terms of OS (P = 0.012), even in stage I patients (P = 0.038).

Conclusions

The present study demonstrates that IMP3 expression is a prognostic marker, with the exception of stage. IMP3 represents a biomarker of unfavorable prognosis even in stage I patients.

Insulin-Like Growth Factor II mRNA-Binding Protein 3 (IMP3) as a Useful Immunohistochemical Marker for the Diagnosis of Adenocarcinoma of Small Intestine

The biological characteristics and roles of insulin-like growth factor II mRNA-binding protein 3 protein (IMP3) expression in small-intestinal adenocarcinoma were investigated. The value of IMP3 immunostaining in the diagnosis of small-intestinal epithelial lesions was also evaluated. Immunohistochemical expression of IMP3 in normal small-intestinal mucosa adjacent to adenoma and adenocarcinoma lesions, and inflamed duodenal and ileal mucosa was analyzed. Samples assessed were: duodenal ulcer (n=6), Crohn’s disease (n=5), low-grade small-intestinal adenoma (n=10), high-grade small-intestinal adenoma (n=13), small-intestinal adenocarcinoma (n=23), lymph node metastases (LNM; n=7), and preoperative biopsies of small-intestinal adenocarcinoma (n=6). Immunohistochemical expression of Ki-67 and p53 was also analyzed in adenoma and adenocarcinoma samples. IMP3 was not expressed in normal epithelium, but weakly expressed in reparative epithelium. Meanwhile, increased IMP3 expression was associated with a higher degree of dysplasia in adenomas, higher T classification, LNM, Ki-67 positivity, histological differentiation, and lower 5-year disease-free survival, but not p53 expression in adenocarcinoma. IMP3 expression appears to be a late event in the small-intestinal carcinogenesis. Assessing the IMP3 staining pattern can be useful in the diagnosis of small-intestinal epithelial lesions when used in conjunction with other histological criteria.

The Discovery of Novel Biomarkers Improves Breast Cancer Intrinsic Subtype Prediction and Reconciles the Labels in the METABRIC Data Set

BACKGROUND

The prediction of breast cancer intrinsic subtypes has been introduced as a valuable strategy to determine patient diagnosis and prognosis, and therapy response. The PAM50 method, based on the expression levels of 50 genes, uses a single sample predictor model to assign subtype labels to samples. Intrinsic errors reported within this assay demonstrate the challenge of identifying and understanding the breast cancer groups. In this study, we aim to: a) identify novel biomarkers for subtype individuation by exploring the competence of a newly proposed method named CM1 score, and b) apply an ensemble learning, as opposed to the use of a single classifier, for sample subtype assignment. The overarching objective is to improve class prediction.

METHODS AND FINDINGS

The microarray transcriptome data sets used in this study are: the METABRIC breast cancer data recorded for over 2000 patients, and the public integrated source from ROCK database with 1570 samples. We first computed the CM1 score to identify the probes with highly discriminative patterns of expression across samples of each intrinsic subtype. We further assessed the ability of 42 selected probes on assigning correct subtype labels using 24 different classifiers from the Weka software suite. For comparison, the same method was applied on the list of 50 genes from the PAM50 method.

CONCLUSIONS

The CM1 score portrayed 30 novel biomarkers for predicting breast cancer subtypes, with the confirmation of the role of 12 well-established genes. Intrinsic subtypes assigned using the CM1 list and the ensemble of classifiers are more consistent and homogeneous than the original PAM50 labels. The new subtypes show accurate distributions of current clinical markers ER, PR and HER2, and survival curves in the METABRIC and ROCK data sets. Remarkably, the paradoxical attribution of the original labels reinforces the limitations of employing a single sample classifiers to predict breast cancer intrinsic subtypes.

Are clear cell carcinomas of the ovary and endometrium phenotypically identical? A proteomic analysis

Phenotypic differences between otherwise similar tumors arising from different gynecologic locations may be highly significant in understanding the underlying driver molecular events at each site and may potentially offer insights into differential responses to treatment. In this study, the authors sought to identify and quantify phenotypic differences between ovarian clear cell carcinoma (OCCC) and endometrial clear cell carcinoma (ECCC) using a proteomic approach. Tissue microarrays were constructed from tumor samples of 108 patients (54 ECCCs and 54 OCCCs). Formalin-fixed samples on microarray slides were analyzed by matrix-assisted laser desorption/ionization mass spectrometry, and 730 spectral peaks were generated from the combined data set. A linear mixed-effect model with random intercept was used to generate 93 (12.7%) peaks that were significantly different between OCCCs and ECCCs at the fold cutoffs of 1.5 and 0.667 and an adjusted P value cutoff of 1.0 × 10(-10). Liquid chromatography-tandem mass spectrometry was performed on selected cores from each group, and peptides identified therefrom were compared with lists of statistically significant peaks from the aforementioned linear mixed-effects model to find matches within 0.2 Da. A total of 53 candidate proteins were thus identified as being differentially expressed in OCCCs and ECCCs, 45 (85%) of which were expressed at higher levels in ECCCs than OCCCs. These proteins were functionally diverse and did not highlight a clearly dominant cellular theme or molecular pathway. Although ECCCs and OCCCs are very similar, some phenotypic differences are demonstrable. Additional studies of these differentially expressed proteins may ultimately clarify the significance of these differences.

Prognostic value of the IASLC/ATS/ERS classification and IMP3 expression in lung adenocarcinoma of Chinese cases

The IASLC/ATS/ERS classification system was proposed in 2011 to improve the histological subtypes of lung adenocarcinoma, while the prognostic value of the combination of histological predominant subtypes is not consistent. IMP3 is an oncofetal protein which has been proved associated with aggressive tumor behavior in malignancies, but few reports were investigated in lung adenocarcinoma. The aim of this study is to explore the prognostic value of the IASLC/ATS/ERS classification and IMP3 expression in lung adenocarcinoma of Chinese cases. A total of 196 cases were classified according to the IASLC/ATS/ERS classification system and immunohistochemically analyzed by using a monoclonal antibody against IMP3. Univariate survival analysis indicated patients with solid-predominant subtype had shorter disease-free survival (P = 0.003) and overall survival (P = 0.014) compared to those with non-solid predominant subtype. Multivariate survival analysis revealed that solid-predominant subtype could be an independent prognostic factor for disease-free survival (HR: 1.22, 95% CI: 1.05-1.41; P = 0.008). Analysis of IMP3 expression showed that IMP3 was more frequently overexpressed in tumors with advanced pTNM stage (P < 0.001), larger tumor size (P = 0.036), poorer histological differentiation (P < 0.001), lymph node metastasis (P < 0.001), and solid-predominant subtype (P < 0.001). Survival analysis also confirmed that patients in IMP3 high-expression group had both worse disease-free survival (P = 0.039) and overall survival (P = 0.029) than those in IMP3 low-expression group. Our results illustrated that solid-predominant subtype according to the IASLC/ATS/ERS classification is an independent prognostic factor, and IMP3 overexpression is associated with aggressive tumor behavior and poor clinical outcome in lung adenocarcinoma.

The role of the oncofetal IGF2 mRNA-binding protein 3 (IGF2BP3) in cancer

The post-transcriptional control of gene expression mediated by RNA-binding proteins (RBPs), long non-coding RNAs (lncRNAs) as well as miRNAs is essential to determine tumor cell fate and thus is a major determinant in cancerogenesis. The IGF2 mRNA binding protein family (IGF2BPs) comprises three RBPs. Two members of the family, IGF2BP1 and IGF2BP3, are bona fide oncofetal proteins, which are de novo synthesized in various human cancers. In vitro studies revealed that IGF2BPs serve as post-transcriptional fine-tuners modulating the expression of genes implicated in the control of tumor cell proliferation, survival, chemo-resistance and metastasis. Consistently, the expression of both IGF2BP family members was reported to correlate with an overall poor prognosis and metastasis in various human cancers. Due to the fact that most reports used a pan-IGF2BP antibody for studying IGF2BP expression in cancer, paralogue-specific functions can barely be evaluated at present. Nonetheless, the accordance of IGF2BPs' role in promoting an aggressive phenotype of tumor-derived cells in vitro and their upregulated expression in aggressive malignancies provides strong evidence that IGF2BPs are powerful post-transcriptional oncogenes enhancing tumor growth, drug-resistance and metastasis. This suggests IGF2BPs as powerful biomarkers and candidate targets for cancer therapy.