NAP1L1 is a prognostic biomarker and contribute to doxorubicin chemotherapy resistance in human hepatocellular carcinoma

CircDCAF8 promotes the progression of hepatocellular carcinoma through miR-217/NAP1L1 Axis, and induces angiogenesis and regorafenib resistance via exosome-mediated transfer

BACKGROUND

Circular RNAs (circRNAs), which are a new type of single-stranded circular RNA, have significant involvement in progression of many diseases, including tumors. Currently, multiple circRNAs have been identified in hepatocellular carcinoma (HCC). Our study aims to investigate the function and mechanism of circDCAF8 in HCC.

METHODS

The expression of circDCAF8 (hsa_circ_0014879) in HCC and para-carcinoma tissue samples was determined using quantitative real-time polymerase chain reaction (qRT-PCR). The biological function of circDCAF8 in HCC was confirmed by experiments conducted both in vitro and in vivo. And the relationship between circDCAF8, miR-217 and NAP1L1 was predicted by database and verified using qRT-PCR, RNA-binding protein immunoprecipitation (RIP) and dual-luciferase reporter assays. Exosomes isolated from HCC cells were utilized to assess the connection of exosomal circDCAF8 with HCC angiogenesis and regorafenib resistance.

RESULTS

CircDCAF8 is upregulated in HCC tissues and cell lines, and is linked to an unfavourable prognosis for HCC patients. Functionally, circDCAF8 was proved to facilitate proliferation, migration, invasion and Epithelial-Mesenchymal Transformation (EMT) in HCC cells. Animal examinations also validated the tumor-promoting characteristics of circDCAF8 on HCC. Besides, exosomal circDCAF8 promoted angiogenesis in HUVECs. Mechanistically, circDCAF8 interacted with miR-217 and NAP1L1 was a downstream protein of miR-217. CircDCAF8 promoted NAP1L1 expression by sponging miR-217. In addition, exosomes may transfer circDCAF8 from regorafenib-resistant HCC cells to sensitive cells, where it would confer a resistant phenotype.

CONCLUSION

CircDCAF8 facilitates HCC proliferation and metastasis via the miR-217/NAP1L1 axis. Meanwhile, circDCAF8 can promote angiogenesis and drive resistance to regorafenib, making it a viable therapeutic target for HCC patients.

SP2-induced circPUM1 modulates chemoresistance and nature killer cell toxicity in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a type of tumour found in the cavity that is characterized by differentiation and metastasis to the lymph nodes. Although diagnosis strategy and clinical treatment have recently improved, the outcomes for OSCC patients remain unsatisfactory. This study verified the characteristics of circPUM1 in OSCC cells, subsequently generating dysregulated circPUM1 cell models, showing that circPUM1 promoted chemoresistance and natural killer (NK) cell toxicity. Furthermore, the transcription factor SP2 regulated the expression of circPUM1 in OSCC cells, circPUM1 acted as a molecular sponge for miR-770-5p. Moreover, Nucleosome Assembly Protein 1 Like 1 (NAP1L1) is a downstream target for miR-770-5p and essential for circPUM1-mediated cisplatin resistance and NK cell cytotoxicity in OSCC cells. The network composed of SP2, circPUM1, miR-770-5p and NAP1L1 in OSCC appears to be a promising avenue for the development of novel targets for diagnosing or treating OSCC.

Nucleosome assembly protein 1-like 1 (NAP1L1) in gastric cancer patients: a potential biomarker with diagnostic and prognostic utility

BACKGROUND

The nucleosome assembly protein 1-like 1 (NAP1L1) is suggested to have an oncogenic role in several tumors based on its overexpression. However, its diagnostic and prognostic role in gastric cancer remains unclarified. This study aimed to evaluate the diagnostic and prognostic utility of NAP1L1 in gastric cancer patients.

METHODS

A total of 85 patients [mean (SD) age: 60.9 (1.6) years, 49.4% were males] with newly-diagnosed gastric cancer and 40 healthy individuals [mean (SD) age: 60.7 (1.7) years, 52.5% were males] were included. Data on patient demographics (age, gender), TNM stages and tumor size, and the serum NAP1L1 levels were recorded.

RESULTS

Serum NAP1L1 levels were significantly higher in gastric cancer patients than in control subjects [12 (9.5-13.8) vs. 1.8 (1.5-2.4) ng/mL, p < 0.001]. Also, certain tumor characteristics such as tumor size of >4 vs. <4 cm (p < 0.001), M1 vs. M0 stage (p < 0.001), N2 vs. N0 and N1 stage (p < 0.001), and T4 vs. lower T stage (p < 0.001) were associated with significantly higher serum NAP1L1 levels in gastric cancer patients.

CONCLUSIONS

Our findings revealed for the first time that serum levels for NAP1L1 were overexpressed in the gastric cancer, as also correlated with the disease progression. NAP1L1 seems to be a potential biomarker for gastric cancer, providing clinically important information on early diagnosis and risk stratification.

Targeting MYH9 represses USP14-mediated NAP1L1 deubiquitination and cell proliferation in glioma

Myosin heavy chain 9 (MYH9) plays an important role in a number of diseases. Nevertheless, the function of MYH9 in glioma is unclear. The present research aimed to investigate the role of MYH9 in glioma and determine whether MYH9 is involved in the temozolomide chemoresistance of glioma cells. Our results showed that MYH9 increased the proliferation and temozolomide resistance of glioma cells. The mechanistic experiments showed that the binding of MYH9 to NAP1L1, a potential promoter of tumor proliferation, inhibited the ubiquitination and degradation of NAP1L1 by recruiting USP14. Upregulation of NAP1L1 increased its binding with c-Myc and activated c-Myc, which induced the expression of CCND1/CDK4, promoting glioma cell temozolomide resistance and proliferation. Additionally, we found that MYH9 upregulation was strongly related to patient survival and is therefore a negative factor for patients with glioma. Altogether, our results show that MYH9 plays a role in glioma progression by regulating NAP1L1 deubiquitination. Thus, targeting MYH9 is a potential therapeutic strategy for the clinical treatment of glioma in the future.

Evaluation and Application of Drug Resistance by Biomarkers in the Clinical Treatment of Liver Cancer

Liver cancer is one of the most lethal cancers in the world, mainly owing to the lack of effective means for early monitoring and treatment. Accordingly, there is considerable research interest in various clinically applicable methods for addressing these unmet needs. At present, the most commonly used biomarker for the early diagnosis of liver cancer is alpha-fetoprotein (AFP), but AFP is sensitive to interference from other factors and cannot really be used as the basis for determining liver cancer. Treatment options in addition to liver surgery (resection, transplantation) include radiation therapy, chemotherapy, and targeted therapy. However, even more expensive targeted drug therapies have a limited impact on the clinical outcome of liver cancer. One of the big reasons is the rapid emergence of drug resistance. Therefore, in addition to finding effective biomarkers for early diagnosis, an important focus of current discussions is on how to effectively adjust and select drug strategies and guidelines for the treatment of liver cancer patients. In this review, we bring this thought process to the drug resistance problem faced by different treatment strategies, approaching it from the perspective of gene expression and molecular biology and the possibility of finding effective solutions.

Histone Chaperones and Digestive Cancer: A Review of the Literature

BACKGROUND

The global burden of digestive cancer is expected to increase. Therefore, crucial for the prognosis of patients with these tumors is to identify early diagnostic markers or novel therapeutic targets. There is accumulating evidence connecting histone chaperones to the pathogenesis of digestive cancer. Histone chaperones are now broadly defined as a class of proteins that bind histones and regulate nucleosome assembly. Recent studies have demonstrated that multiple histone chaperones are aberrantly expressed and have distinct roles in digestive cancers.

OBJECTIVE

The purpose of this review is to present the current evidence regarding the role of histone chaperones in digestive cancer, particularly their mechanism in the development and progression of esophageal, gastric, liver, pancreatic, and colorectal cancers. In addition, the prognostic significance of particular histone chaperones in patients with digestive cancer is discussed.

METHODS

According to PRISMA guidelines, we searched the PubMed, Embase, and MEDLINE databases to identify studies on histone chaperones and digestive cancer from inception until June 2022.

RESULTS

A total of 104 studies involving 21 histone chaperones were retrieved.

CONCLUSIONS

This review confirms the roles and mechanisms of selected histone chaperones in digestive cancer and suggests their significance as potential prognostic biomarkers and therapeutic targets. However, due to their non-specificity, more research on histone chaperones should be conducted in the future to elucidate novel strategies of histone chaperones for prognosis and treatment of digestive cancer.

NAP1L1 Functions as a Novel Prognostic Biomarker Associated With Macrophages and Promotes Tumor Progression by Influencing the Wnt/β-Catenin Pathway in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is regarded as one of the universal cancers in the world. Therefore, our study is based on clinical, molecular mechanism and immunological perspectives to analyze how NAP1L1 affects the progression of HCC. To begin with, the gene expression datasets and clinical data of GSE14520, GSE76427, ICGC, and TCGA are originated from GEO, ICGC, and TCGA databases. Subsequently, DEG screening was performed on data using R studio, and we finally found that 2,145 overlapping DEGs were screened from four datasets at the end. Then, we used R studio to filter the survival-related genes of the GSE76427 and ICGC datasets, and we screened out 101 survival-related genes. Finally, 33 common genes were screened out from 2,145 overlapping DEGs and 101 survival-related genes. Then, NAP1L1 was screened from 33 common genes using the CytoHubba plug-in in Cytoscape software. Furthermore, ground on GEO, ICGC, and TCGA databases, the survival analysis, clinical feature analysis, univariate/multivariate regression analysis, and multiple GSEA were used to study NAP1L1. The Conclusion claimed that HCC patients with higher expression levels of NAP1L1 had a poorer prognosis than those with lower expression levels. Thus, we believe that NAP1L1 is an independent prognostic factor for HCC. In order to shed light on NAP1L1’s molecular mechanism promoting the progression of HCC closely, the GSEA tool was applied to complete the GSEA of the four datasets. Furthermore, the results confirmed that NAP1L1 could promote HCC progression by regulating the G2/M transition of the cell cycle and Wnt signaling pathway. Western blot and flow cytometry were also performed to understand those mechanisms in this study. The result of Western blot showed that NAP1L1 silencing led to downregulation of CDK1 and β-catenin proteins; the result of flow cytometry showed that cell numbers in the G2 phase were significantly increased when NAP1L1 was silenced. Thus, we claimed that NAP1L1 might promote HCC progression by activating the Wnt signaling pathway and promoting cell cycle G2/M transition. In addition, ground on GSE14520 and GSE76427 datasets, and ICGC and TCGA databases, the correlation between NAP1L1 and immune cells was analyzed in HCC patients. At the same time, the TISIDB online database and the TIMER online database were testified to the association between NAP1L1 and immune cells. Hence, the summary shows that NAP1L1 was connected with a certain amount of immune cells. We can speculate that NAP1L1 may influence macrophages to promote HCC progression through some potential mechanisms.

NAP1L1 promotes tumor proliferation through HDGF/C-JUN signaling in ovarian cancer

Background

Nucleosome assembly protein 1-like 1 (NAP1L1) is highly expressed in various types of cancer and plays an important role in carcinogenesis, but its specific role in tumor development and progression remains largely unknown. In this study, we suggest the potential of NAP1L1 as a prognostic biomarker and therapeutic target for the treatment of ovarian cancer (OC).

Methods

In our study, a tissue microarray (TMA) slide containing specimens from 149 patients with OC and 11 normal ovarian tissues underwent immunohistochemistry (IHC) to analyze the correlation between NAP1L1 expression and clinicopathological features. Loss-of- function experiments were performed by transfecting siRNA and following lentiviral gene transduction into SKOV3 and OVCAR3 cells. Cell proliferation and the cell cycle were assessed by the Cell Counting Kit-8, EDU assay, flow cytometry, colony formation assay, and Western blot analysis. In addition, co-immunoprecipitation (Co-IP) and immunofluorescence assays were performed to confirm the relationship between NAP1L1 and its potential targets in SKOV3/OVCAR3 cells.

Results

High expression of NAP1L1 was closely related to poor clinical outcomes in OC patients. After knocking down NAP1L1 by siRNA or shRNA, both SKOV3 and OVCAR3 cells showed inhibition of cell proliferation, blocking of the G1/S phase, and increased apoptosis in vitro. Mechanism analysis indicated that NAP1L1 interacted with hepatoma-derived growth factor (HDGF) and they were co-localized in the cytoplasm. Furthermore, HDGF can interact with jun proto-oncogene (C-JUN), an oncogenic transformation factor that induces the expression of cyclin D1 (CCND1). Overexpressed HDGF in NAP1L1 knockdown OC cells not only increased the expression of C-JUN and CCND1, but it also reversed the suppressive effects of si-NAP1L1 on cell proliferation.

Conclusions

Our data demonstrated that NAP1L1 could act as a prognostic biomarker in OC and can interact with HDGF to mediate the proliferation of OC, and this process of triggered proliferation may contribute to the activation of HDGF/C-JUN signaling in OC cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09356-z.

NAP1L5 Promotes Nucleolar Hypertrophy and Is Required for Translation Activation During Cardiomyocyte Hypertrophy

Pathological growth of cardiomyocytes during hypertrophy is characterized by excess protein synthesis; however, the regulatory mechanism remains largely unknown. Using a neonatal rat ventricular myocytes (NRVMs) model, here we find that the expression of nucleosome assembly protein 1 like 5 (Nap1l5) is upregulated in phenylephrine (PE)-induced hypertrophy. Knockdown of Nap1l5 expression by siRNA significantly blocks cell size enlargement and pathological gene induction after PE treatment. In contrast, Adenovirus-mediated Nap1l5 overexpression significantly aggravates the pro-hypertrophic effects of PE on NRVMs. RNA-seq analysis reveals that Nap1l5 knockdown reverses the pro-hypertrophic transcriptome reprogramming after PE treatment. Whereas, immune response is dominantly enriched in the upregulated genes, oxidative phosphorylation, cardiac muscle contraction and ribosome-related pathways are remarkably enriched in the down-regulated genes. Although Nap1l5-mediated gene regulation is correlated with PRC2 and PRC1, Nap1l5 does not directly alter the levels of global histone methylations at K4, K9, K27 or K36. However, puromycin incorporation assay shows that Nap1l5 is both necessary and sufficient to promote protein synthesis in cardiomyocyte hypertrophy. This is attributable to a direct regulation of nucleolus hypertrophy and subsequent ribosome assembly. Our findings demonstrate a previously unrecognized role of Nap1l5 in translation control during cardiac hypertrophy.

Trametes robiniophila represses angiogenesis and tumor growth of lung cancer via strengthening let-7d-5p and targeting NAP1L1

Trametes robiniophila (Huaier) is available to refrain lung cancer (LC) cell progression, but its impact and mechanism on angiogenesis of LC are not proved. The study was to explore the potential mechanism of Huaier repressing angiogenesis and tumor growth in LC via strengthening let-7d-5p and targeting NAP1L1. Let-7d-5p and NAP1L1 expression was detected in LC tissues and cells (A549). Pretreatment of A549 cells was with Huaier. Transfection of changed let-7d-5p and NAP1L1 was to A549 cells to uncover their roles in LC cell progression with angiogenesis. Evaluation of the impact of let-7d-5p on angiogenesis in LC was in vitro in a mouse xenograft model. Identification of the targeting of let-7d-5p with NAP1L1 was clarified. The results clarified reduced let-7d-5p but elevated NAP1L1 were manifested in LC. Huaier restrained angiogenesis and tumor growth of LC in vivo and in vitro; Augmented let-7d-5p or declined NAP1L1 motivated the therapy of Huaier on LC; Let-7d-5p negatively modulated NAP1L1; Elevated NAP1L1 reversed the influence of enhancive let-7d-5p. These results strongly suggest that Huaier represses angiogenesis and tumor growth in LC via strengthening let-7d-5p and targeting NAP1L1. Huaier/let-7d-5p/NAP1L1 axis is supposed to be a promising target for the treatment of angiogenesis and tumor growth in LC via elevated let-7d-5p and targeted NAP1L1.

NAP1L1 interacts with hepatoma-derived growth factor to recruit c-Jun inducing breast cancer growth

BACKGROUND

Breast cancer is a common cancer among women in the world. However, its pathogenesis is still to be determined. The role and molecular mechanism of Nucleosome Assembly Protein 1 Like 1 (NAP1L1) in breast cancer have not been reported. Elucidation of molecular mechanism might provide a novel therapeutic target for breast cancer treatment.

METHODS

A bioinformatics analysis was conducted to determine the differential expression of NAP1L1 in breast cancer and find the potential biomarker that interacts with NAP1L1 and hepatoma-derived growth factor (HDGF). The expression of NAP1L1 in tissues was detected by using immunohistochemistry. Breast cancer cells were transfected with the corresponding lentiviral particles and siRNA. The efficiency of transfection was measured by RT-qPCR and western blotting. Then, MTT, Edu, plate clone formation, and subcutaneous tumorigenesis in nude mice were used to detect the cell proliferation in breast cancer. Furthermore, coimmunoprecipitation (Co-IP) assay and confocal microscopy were performed to explore the detailed molecular mechanism of NAP1L1 in breast cancer.

RESULTS

In this study, NAP1L1 protein was upregulated based on the Clinical Proteomic Tumor Analysis Consortium (CPTAC) database. Consistent with the prediction, immunohistochemistry staining showed that NAP1L1 protein expression was significantly increased in breast cancer tissues. Its elevated expression was an unfavorable factor for breast cancer clinical progression and poor prognosis. Stably or transiently knocking down NAP1L1 reduced the cell growth in vivo and in vitro via repressing the cell cycle signal in breast cancer. Furthermore, the molecular basis of NAP1L1-induced cell cycle signal was further studied. NAP1L1 interacted with the HDGF, an oncogenic factor for tumors, and the latter subsequently recruited the key oncogenic transcription factor c-Jun, which finally induced the expression of cell cycle promoter Cyclin D1(CCND1) and thus the cell growth of breast cancer.

CONCLUSIONS

Our data demonstrated that NAP1L1 functions as a potential oncogene via interacting with HDGF to recruit c-Jun in breast cancer.

NAP1L1 targeting suppresses the proliferation of nasopharyngeal carcinoma

Nucleosome assembly protein 1-like 1 (NAP1L1) is significantly involved in the development of various cancers. However, its role in the molecular mechanism of nasopharyngeal carcinoma (NPC) remains undetermined. In this study, we detected the upregulated expression of NAP1L1 mRNA and protein levels by quantitative polymerase chain reaction and Western blot analysis in NPC cell lines. Results of the immunohistochemistry analysis of NPC tissue biopsies showed that upregulated NAP1L1 protein expression promoted NPC progression and negatively correlated with poor prognosis in NPC patients. Suppression of NAP1L1 expression by small interfering RNA (siRNA) or small hairpin RNA (shRNA) methods significantly decreased cell proliferation in vivo and in vitro. Mechanism analysis revealed that the regulation of cell growth was enriched by Gene Set Enrichment Analysis based on RNA sequencing data. Cell cycle-induced genes CCND1 and E2F1 were downregulated in NAP1L1 knockdown NPC cells. Reduced NAP1L1 suppressed the recruitment of hepatoma-derived growth factor (HDGF) and decreased its expression. Knockdown of HDGF reduced the expression of c-JUN, a key oncogenic transcription factor that can induce the expression of cyclin D1 (CCND1), reducing cell cycle progression and suppressing cell growth in NPC. Transfecting HDGF or c-JUN could reverse the growth-suppressive effects in NAP1L1-downregulated NPC cells. The data obtained in this study suggest that NAP1L1 acts as a potential oncogene by activating HDGF/c-JUN/CCND1 signaling in NPC.

Nucleosome assembly protein 1-like 4, a new therapeutic target for proliferation and invasion of melanoma cells

BACKGROUND

Melanoma is one of the deadliest skin cancers. The treatment of advanced melanoma has been dramatically improved by immune checkpoint inhibitors and targeted therapies. However, many patients still do not respond to these therapies.

OBJECTIVE

To investigate whether NAP1L4 can be a new therapeutic target for melanoma.

METHODS

Immunohistochemical analysis of human nevus and melanoma tissues was performed. Real-time RT-PCR and immunoblotting were performed using human samples and melanoma cell lines. Next, we examined the effect of NAP1L4 knockdown in melanoma cell lines using cell migration and invasion assays. To investigate the molecular mechanism related to these results, immunoblotting of p21 and Slug was examined. MMP-2 and MMP-9 activity assays were also performed. Further, pathway analysis between NAP1L4 and MMP-2 was performed. Finally, the effects of NAP1L4 knockdown on cell proliferation, apoptosis, and cell cycle were analyzed.

RESULTS

NAP1L4 was overexpressed in melanoma tissues compared to the nevus tissue. NAP1L4 knockdown reduced melanoma cell migration and invasion. NAP1L4 knockdown upregulated p21 and downregulated Slug expression in melanoma cells. NAP1L4 knockdown decreased the active levels of MMP-2 in the supernatant from melanoma cells. NAP1L4 knockdown inhibited apoptosis in camptothecin-induced DNA damage, induced cell cycle arrest at the G1/S phase, and inhibited cell proliferation.

CONCLUSIONS

NAP1L4 may play a role in cell migration and invasion in melanoma cells through the regulation of Slug. We propose that NAP1L4 can be a new therapeutic target for proliferation and invasion of melanoma cells.

CircRNA GFRA1 promotes hepatocellular carcinoma progression by modulating the miR-498/NAP1L3 axis

Circular RNAs (circRNAs) play essential roles in tumorigenesis and tumor progression. CircRNA GFRA1 (circGFRA1) was dysregulated in many cancer samples and acted as an independent marker for prediction of survivals in various cancer patients. However, the functions and molecular mechanisms of circGFRA1 in hepatocellular carcinoma (HCC) remain unclear. We collected 62 HCC tissues and normal adjacent tissues to evaluate the expression of circGFRA1 and the relationship between circGFRA1 expression and HCC patients' survival. We carried out a list of characterization experiments to investigate the roles and underling mechanisms of circGFRA1 and miR-498 in HCC progressions. CircGFRA1 was greatly increased in HCC tissues and cells, and the over-expression of circGFRA1 was intimately related with the advanced clinical stage and poor survival of HCC patients. The expression of circGFRA1 was negatively correlated with the expression of miR-498, but a positive correlation was found between circGFRA1 and NAP1L3 expression in HCC tissues. Silencing circGFRA1 inhibited the growth and invasion of hepatocellular carcinoma. Moreover, miR-498 over-expression or NAP1L3 inhibition could abrogate the oncogene role of circGFRA1 in HCC in vivo. Our findings indicated that circGFRA1 contributed to HCC progression by modulating the miR-498/NAP1L3 axis in HCC.

Polychemotherapy with Curcumin and Doxorubicin via Biological Nanoplatforms: Enhancing Antitumor Activity

Doxorubicin (DOX) is a well-known chemotherapeutic agent extensively applied in the field of cancer therapy. However, similar to other chemotherapeutic agents such as cisplatin, paclitaxel, docetaxel, etoposide and oxaliplatin, cancer cells are able to obtain chemoresistance that limits DOX efficacy. In respect to dose-dependent side effect of DOX, enhancing its dosage is not recommended for effective cancer chemotherapy. Therefore, different strategies have been considered for reversing DOX resistance and diminishing its side effects. Phytochemical are potential candidates in this case due to their great pharmacological activities. Curcumin is a potential antitumor phytochemical isolated from Curcuma longa with capacity of suppressing cancer metastasis and proliferation and affecting molecular pathways. Experiments have demonstrated the potential of curcumin for inhibiting chemoresistance by downregulating oncogene pathways such as MMP-2, TGF-β, EMT, PI3K/Akt, NF-κB and AP-1. Furthermore, coadministration of curcumin and DOX potentiates apoptosis induction in cancer cells. In light of this, nanoplatforms have been employed for codelivery of curcumin and DOX. This results in promoting the bioavailability and internalization of the aforementioned active compounds in cancer cells and, consequently, enhancing their antitumor activity. Noteworthy, curcumin has been applied for reducing adverse effects of DOX on normal cells and tissues via reducing inflammation, oxidative stress and apoptosis. The current review highlights the anticancer mechanism, side effects and codelivery of curcumin and DOX via nanovehicles.

EZH2 knockdown in tamoxifen-resistant MCF-7 cells unravels novel targets for regaining sensitivity towards tamoxifen

BACKGROUND

Acquired resistance to drug involves multilayered genetic and epigenetic regulation. Inhibition of EZH2 has proven to reverse the tamoxifen resistance back to the sensitive state in breast cancer. However, the molecular players involved in EZH2-mediated effects on tamoxifen-resistant MCF-7 cells are unknown. This study was conducted to understand the global change in proteome profile of tamoxifen-resistant MCF-7 breast cancer cells upon EZH2 knockdown.

METHODS

Tamoxifen resistance MCF-7 breast cancer cells were established using increasing concentrations of 4-hydroxy tamoxifen. Using label free proteomics approach, we studied the alteration in total proteome in resistant cells as well as cells transfected with siEZH2 in comparison to sensitive and cells transfected with non-targeting siRNA.

RESULTS

Here, we report list of proteins that were previously not recognized for their role in tamoxifen resistance and hold a close association with breast cancer patient survival. Proteins Annexin A2, CD44, nucleosome assembly protein 1, and lamin A/C were among the most upregulated protein in tamoxifen-resistant cells that were found to be abrogated upon EZH2 knockdown. The study suggests the involvement for various proteins in acquiring resistance towards tamoxifen and anticipates further research for investigating their therapeutic potentials.

CONCLUSION

Overall, we propose that targeting EZH2 or the molecules down the cascade might be helpful in reacquiring sensitivity to tamoxifen in breast cancer.

NAP1L1: A Novel Human Colorectal Cancer Biomarker Derived From Animal Models of Apc Inactivation

Introduction

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide and most deaths result from metastases. We have analyzed animal models in which Apc, a gene that is frequently mutated during the early stages of colorectal carcinogenesis, was inactivated and human samples to try to identify novel potential biomarkers for CRC.

Materials and Methods

We initially compared the proteomic and transcriptomic profiles of the small intestinal epithelium of transgenic mice in which Apc and/or Myc had been inactivated. We then studied the mRNA and immunohistochemical expression of one protein that we identified to show altered expression following Apc inactivation, nucleosome assembly protein 1–like 1 (NAP1L1) in human CRC samples and performed a prognostic correlation between biomarker expression and survival in CRC patients.

Results

Nap1l1 mRNA expression was increased in mouse small intestine following Apc deletion in a Myc dependant manner and was also increased in human CRC samples. Immunohistochemical NAP1L1 expression was decreased in human CRC samples relative to matched adjacent normal colonic tissue. In a separate cohort of 75 CRC patients, we found a strong correlation between NAP1L1 nuclear expression and overall survival in those patients who had stage III and IV cancers.

Conclusion

NAP1L1 expression is increased in the mouse small intestine following Apc inactivation and its expression is also altered in human CRC. Immunohistochemical NAP1L1 nuclear expression correlated with overall survival in a cohort of CRC patients. Further studies are now required to clarify the role of this protein in CRC.

A novel seven-gene signature as Prognostic Biomarker in Hepatocellular Carcinoma

Purpose: Our study is designed to develop and certify a promising prognostic signature for hepatocellular carcinoma (HCC).

Materials and methods: We retrospectively analyzed mRNA expression profiles and clinicopathological data fetched from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. We formulated a prognostic seven-gene signature composed of differentially expressed mRNAs (DEmRNAs) between HCC and nonneoplastic tissues through univariate Cox regression analysis. The receiver operating characteristic (ROC) curve, survival analysis and multivariate Cox regression analysis as well as nomograms were utilized to assess the prognostic performance of the seven-gene signature.

Results: The risk score based on a seven-gene signature categorized HCC subjects into a high- and low-risk group. There was significantly discrepant overall survival (OS) between patients in both groups and the corresponding ROC curve revealed a satisfactory predictive performance in HCC survival in both TCGA and GSE76427 cohort. Multivariate Cox regression analysis demonstrated that a seven-gene signature was an independently prognostic factor for HCC. Nomograms combining this prognostic signature with significant clinical characteristics conferred a crucial reference to predict the 1-,3- and 5 years OS.

Conclusions: Our study defined a promising seven-gene signature and nomogram model to forecast the OS of HCC patients, which is instrumental in clinical decision and personalized therapy.

Breast Heterogeneity: Obstacles to Developing Universal Biomarkers of Breast Cancer Initiation and Progression

BACKGROUND

Predicting outcomes and response to therapy through biomarkers is a major challenge in cancer research. In previous studies, we suggested that inappropriate "normal" tissue samples used for comparison with tumors, inter-individual heterogeneity in gene expression, and genetic ancestry all influence biomarker expression in tumors. The aim of this study was to investigate these factors in breast cancer using breast tissues from healthy women and normal tissue adjacent to tumor (NAT) with matrix metalloproteinase 7 (MMP7) as a candidate biomarker.

STUDY DESIGN

RNA sequencing was performed on primary luminal progenitor cells from healthy breast, NATs, and tumors to identify transcriptomes enriched in NATs and breast cancer. Expression of select genes was validated via quantitative reverse transcription polymerase chain reaction of RNA and via immunohistochemistry of a tissue microarray of normal, NAT, and tumor samples of different genetic ancestry.

RESULTS

Twenty-six genes were significantly overexpressed in NATs and tumors compared with healthy controls at messenger RNA level and formed a para-inflammatory network. MMP7 had the greatest expression in tumor cells, with upregulation confirmed by quantitative reverse transcription polymerase chain reaction. Tumor-enriched but not NAT-enriched expression of MMP7 compared with healthy controls was reproduced at protein levels. When stratified by genetic ancestry, tumor-specific increase of MMP7 reached statistical significance in women of European ancestry.

CONCLUSIONS

Transcriptome differences across healthy, NAT, and tumor tissue in breast cancer demonstrate an active para-inflammatory network in NATs and indicate unsuitability of NATs as "normal controls" in biomarker discovery. The discordance between transcriptomic and proteomic MMP7 expression in NATs and the influence of genetic ancestry on its protein expression highlight the complexity in developing universally acceptable biomarkers of breast cancer and the importance of genetic ancestry in biomarker development.