Long non-coding RNA XIST predicts worse prognosis in digestive system tumors: a systemic review and meta-analysis

The prognostic value of systemic inflammation response index in digestive system carcinomas: a systematic review and meta-analysis

BACKGROUND

Digestive system carcinomas (DSC) constitute a significant proportion of solid tumors, with incidence rates rising steadily each year. The systemic inflammation response index (SIRI) has been identified as a potential prognostic marker for survival in various types DSC. This meta-analysis aimed to evaluate the prognostic value of SIRI in patients with DSC.

METHODS

We conducted a comprehensive literature search of PubMed, Web of Science Core Collection, Embase, and Cochrane Library databases, searching for studies published from inception to May 30, 2023. Eligible studies included cohort studies that assessed the association between pre-treatment SIRI levels and DSC prognosis. We extracted and synthesized hazard ratios (HRs) and 95% confidence intervals (CIs) using STATA/SE 12.0, stratifying HRs based on univariable and multivariable analysis. Due to substantial heterogeneity, we applied a random-effect model for all pooled analyses. The primary outcome of interest was the overall survival (OS), while secondary outcomes included progression-free survival (PFS), disease-free survival (DFS), time to progression (TTP), and disease specific survival (DSS). Publication bias was evaluated using Begg's test and Egger's tests.

RESULTS

A total of 34 cohort studies encompassing 9628 participants were included in this meta-analysis. Notable heterogeneity was observedin the OS (I2 = 76.5%, p < 0.001) and PFS (I2 = 82.8%, p = 0.001) subgroups, whereas no significant heterogeneity was detected in the DFS, TTP, and DSS subgroups. Elevated SIRI was found to be significantly associated with shorter OS (HR = 1.98, 95% CI: 1.70-2.30, tau2 = 0.0966) and poorer PFS (HR = 2.36, 95% CI: 1.58-3.53, tau2 = 0.1319), DFS (HR = 1.80, 95% CI: 1.61-2.01, tau2 < 0.0001), TTP (HR = 2.03, 95% CI: 1.47-2.81, tau2 = 0.0232), and DSS (HR = 1.99, 95% CI: 1.46-2.72, tau2 < 0.0001). Furthermore, an increase in SIRI following treatment was linked to reduced OS, TTP, and DFS, while a decrease in SIRI post-treatment corresponded with improved OS, TTP, and DFS compared to baseline levels.

CONCLUSIONS

Elevated SIRI is associated with poorer clinical outcomes in patients with DSC. This index may serve as a valuable prognostic biomarker, offering a promising tool for predicting survival in DSC patients.

PROSPERO

REGISTRATION NUMBER: CRD42023430962.

Colon Cancer-Derived Exosomal LncRNA-XIST Promotes M2-like Macrophage Polarization by Regulating PDGFRA

Colon cancer ranks second in overall cancer-related deaths and poses a serious risk to human life and health. In recent years, exosomes are believed to play an important and significant role in cancer, especially tumor-derived exosomes (TDEs). Previous studies have highlighted the pivotal role of exosomes in tumor development, owing to their ability to mediate communication between tumor cells and macrophages, induce macrophage M2 polarization, and facilitate the progression of tumorigenesis. In this study, we revealed that colon cancer-derived exosomes promoted M2-like macrophage polarization. Moreover, exosome-induced M2-like macrophages, in turn, promoted the proliferation, migration, and invasion abilities of colon cancer cells. Specifically, CT26- and HCT116-derived exosomes led to the activation of AKT, ERK, and STAT3/6 signaling pathways in THP-1(Mφ) cells. Furthermore, our findings showed that colon cancer-derived exosomes secreted lncXIST to sponge miR-17-5p, which, in turn, promoted the expression of PDGFRA, a common gene found in all three signaling pathways, to facilitate M2-like macrophage polarization. Dual-luciferase reporter assays confirmed the binding relationship between lncXIST and miR-17-5p, as well as miR-17-5p and PDGFRA. Collectively, our results highlight the novel role of lncXIST in facilitating macrophage polarization by sponging miR-17-5p and regulating PDGFRA expression.

Macrophage lncRNAs in cancer development: Long-awaited therapeutic targets

In the tumor microenvironment, the interplay among macrophages, cancer cells, and endothelial cells is multifaceted. Tumor-associated macrophages (TAMs), which often exhibit an M2 phenotype, contribute to tumor growth and angiogenesis, while cancer cells and endothelial cells reciprocally influence macrophage behavior. This complex interrelationship highlights the importance of targeting these interactions for the development of novel cancer therapies aimed at disrupting tumor progression and angiogenesis. Accumulating evidence underscores the indispensable involvement of lncRNAs in shaping macrophage functionality and contributing to the development of cancer. Animal studies have further validated the therapeutic potential of manipulating macrophage lncRNA activity to ameliorate disease severity and reduce morbidity rates. This review provides a survey of our current understanding of macrophage-associated lncRNAs, with a specific emphasis on their molecular targets and their regulatory impact on cancer progression. These lncRNAs predominantly govern macrophage polarization, favoring the dominance of M2 macrophages or TAMs. Exosomes or extracellular vesicles mediate lncRNA transfer between macrophages and cancer cells, affecting cellular functions of each other. Moreover, this review presents therapeutic strategies targeting cancer-associated lncRNAs. The insights and findings presented in this review pertaining to macrophage lncRNAs can offer valuable information for the development of treatments against cancer.

Potential roles of lncRNA-XIST/miRNAs/mRNAs in human cancer cells

Long non-coding RNAs (lncRNAs) are non-coding RNAs that contain more than 200 nucleotides but do not code for proteins. In tumorigenesis, lncRNAs can have both oncogenic and tumor-suppressive properties. X inactive-specific transcript (XIST) is a known lncRNA that has been implicated in X chromosome silencing in female cells. Dysregulation of XIST is associated with an increased risk of various cancers. Therefore, XIST can be a beneficial prognostic biomarker for human malignancies. In this review, we attempt to summarize the emerging roles of XIST in human cancers.

Comprehensive analysis of autophagy related long non-coding RNAs in prognosis, immunity, and treatment of muscular invasive bladder cancer

To predict disease outcome in muscle-invasive bladder cancer (MIBC), we constructed a prognostic autophagy-related (PAR) lncRNA signature. Comprehensive bioinformatics analyses were performed using data from TCGA and GTEx databases. Univariate Cox, and least absolute shrinkage and selection operator regression analyses were also performed, based on differentially expressed genes, to identify PAR-related lncRNAs to establish the signature. Furthermore, the Kaplan–Meier OS curve and receiver operating characteristic curve analyses were performed and a nomogram was constructed, all of which together confirmed the strong predictive ability of the constructed signature. Patients with MIBC were then divided into high- and low-risk groups. Gene enrichment and immune infiltration analyses revealed the potential mechanisms in MIBC. We also further evaluated the signature of molecules related to immune checkpoints and the sensitivity toward chemotherapeutic agents and antitumor-targeted drugs to find better treatment prescriptions. We identified a number of PAR-related lncRNA signatures, including HCP5, AC024060.1, NEAT1, AC105942.1, XIST, MAFG-DT, and NR2F1-AS1, which could be valuable prognostic tools to develop more efficient, individualized drug therapies for MIBC patients.

XIST in Brain Cancer

Long non-coding RNAs (lncRNAs) make up the majority of the human genome. They are a group of small RNA molecules that do not code for any proteins but play a primary role in regulating a variety of physiological and pathological processes. X-inactive specific transcript (XIST), one of the first lncRNAs to be discovered, is chiefly responsible for X chromosome inactivation: an evolutionary process of dosage compensation between the sex chromosomes of males and females. Recent studies show that XIST plays a pathophysiological role in the development and prognosis of brain tumors, a heterogeneous group of neoplasms that cause significant morbidity and mortality. In this review, we explore recent advancements in the role of XIST in migration, proliferation, angiogenesis, chemoresistance, and evasion of apoptosis in different types of brain tumors, with particular emphasis on gliomas.

Role of N6-methyladenosine Modification in Cardiac Remodeling

Cardiac remodeling is the critical process in heart failure due to many cardiovascular diseases including myocardial infarction, hypertension, cardiovascular disease and cardiomyopathy. However, treatments for heart failure focusing on cardiac remodeling show relatively limited effectiveness. In recent decades, epitranscriptomic modifications were found abundantly present throughout the progression of cardiac remodeling, and numerous types of biochemical modifications were identified. m6A modification is the methylation of the adenosine base at the nitrogen-6 position, and dysregulation of m6A modification has been implicated in a wide range of diseases. However, function of m6A modifications still remain largely unknown in cardiac diseases, especially cardiac remodeling. LncRNAs are also shown to play a vital role in the pathophysiology of cardiac remodeling and heart failure. The crosstalk between lncRNAs and m6A modification provides a novel prospective for exploring possible regulatory mechanism and therapeutic targets of cardiac remodeling. This review summarizes the role of m6A modification in cardiac remodeling in the current researches.

Biological Function of Long Non-coding RNA (LncRNA) Xist

Long non-coding RNAs (lncRNAs) regulate gene expression in a variety of ways at epigenetic, chromatin remodeling, transcriptional, and translational levels. Accumulating evidence suggests that lncRNA X-inactive specific transcript (lncRNA Xist) serves as an important regulator of cell growth and development. Despites its original roles in X-chromosome dosage compensation, lncRNA Xist also participates in the development of tumor and other human diseases by functioning as a competing endogenous RNA (ceRNA). In this review, we comprehensively summarized recent progress in understanding the cellular functions of lncRNA Xist in mammalian cells and discussed current knowledge regarding the ceRNA network of lncRNA Xist in various diseases. Long non-coding RNAs (lncRNAs) are transcripts that are more than 200 nt in length and without an apparent protein-coding capacity (Furlan and Rougeulle, 2016; Maduro et al., 2016). These RNAs are believed to be transcribed by the approximately 98-99% non-coding regions of the human genome (Derrien et al., 2012; Fu, 2014; Montalbano et al., 2017; Slack and Chinnaiyan, 2019), as well as a large variety of genomic regions, such as exonic, tronic, and intergenic regions. Hence, lncRNAs are also divided into eight categories: Intergenic lncRNAs, Intronic lncRNAs, Enhancer lncRNAs, Promoter lncRNAs, Natural antisense/sense lncRNAs, Small nucleolar RNA-ended lncRNAs (sno-lncRNAs), Bidirectional lncRNAs, and non-poly(A) lncRNAs (Ma et al., 2013; Devaux et al., 2015; St Laurent et al., 2015; Chen, 2016; Quinn and Chang, 2016; Richard and Eichhorn, 2018; Connerty et al., 2020). A range of evidence has suggested that lncRNAs function as key regulators in crucial cellular functions, including proliferation, differentiation, apoptosis, migration, and invasion, by regulating the expression level of target genes via epigenomic, transcriptional, or post-transcriptional approaches (Cao et al., 2018). Moreover, lncRNAs detected in body fluids were also believed to serve as potential biomarkers for the diagnosis, prognosis, and monitoring of disease progression, and act as novel and potential drug targets for therapeutic exploitation in human disease (Jiang W. et al., 2018; Zhou et al., 2019a). Long non-coding RNA X-inactive specific transcript (lncRNA Xist) are a set of 15,000-20,000 nt sequences localized in the X chromosome inactivation center (XIC) of chromosome Xq13.2 (Brown et al., 1992; Debrand et al., 1998; Kay, 1998; Lee et al., 2013; da Rocha and Heard, 2017; Yang Z. et al., 2018; Brockdorff, 2019). Previous studies have indicated that lncRNA Xist regulate X chromosome inactivation (XCI), resulting in the inheritable silencing of one of the X-chromosomes during female cell development. Also, it serves a vital regulatory function in the whole spectrum of human disease (notably cancer) and can be used as a novel diagnostic and prognostic biomarker and as a potential therapeutic target for human disease in the clinic (Liu et al., 2018b; Deng et al., 2019; Dinescu et al., 2019; Mutzel and Schulz, 2020; Patrat et al., 2020; Wang et al., 2020a). In particular, lncRNA Xist have been demonstrated to be involved in the development of multiple types of tumors including brain tumor, Leukemia, lung cancer, breast cancer, and liver cancer, with the prominent examples outlined in Table 1. It was also believed that lncRNA Xist (Chaligne and Heard, 2014; Yang Z. et al., 2018) contributed to other diseases, such as pulmonary fibrosis, inflammation, neuropathic pain, cardiomyocyte hypertrophy, and osteoarthritis chondrocytes, and more specific details can be found in Table 2. This review summarizes the current knowledge on the regulatory mechanisms of lncRNA Xist on both chromosome dosage compensation and pathogenesis (especially cancer) processes, with a focus on the regulatory network of lncRNA Xist in human disease.

LncRNA NORAD as a Novel Predictor of Lymph Node Metastasis and Prognosis in Solid Tumors: A Systematic Review and Meta-Analysis

Background:

Non-coding RNA-activated by DNA damage (NORAD), a novel identified lncRNA, was found to be aberrantly expressed in various types of cancer. This meta-analysis was performed to evaluate the value of lncRNA NORAD as a prognostic biomarker in human cancers.

Methods:

We searched PubMed, Web of Science, PMC, and Embase databases thoroughly for eligible literatures. Studies which explored the relationship of lncRNA NORAD expression with clinical outcomes in human cancers were included in our meta-analysis. Review Manager version 5.3 and Stata SE 12.0 were used to perform the data analyses.

Results:

Our meta-analysis results indicated that cancer patients with high lncRNA NORAD expression tended to have unfavorable overall survival (OS) (HR = 1.67; 95% CI, 1.44-1.95; P < 0.00001). Moreover, elevated lncRNA NORAD expression showed a significant relationship with poor tumor grade (OR = 1.61; 95% CI, 1.01-2.56; P = 0.05) and more lymph node metastasis (LNM) (OR = 2.66; 95% CI, 1.60-4.43; P = 0.0002).

Conclusions:

LncRNA NORAD could serve as a valuable biomarker to predict poor prognosis and LNM in various human tumors.

Prognostic significance of LncRNA GHET1 expression in various cancers: a systematic review and meta-analysis

BACKGROUND

Dysregulated expression of long non-coding RNA gastric carcinoma high expressed transcript 1 (lncRNA GHET1) has been observed in several cancers, however, definite conclusion on the prognostic value of lncRNA GHET1 expression in human cancers has not been determined. The aim of this meta-analysis was to evaluate the prognostic significance of lncRNA GHET1 expression in cancers.

METHODS

PubMed, Web of Science and Embase were comprehensively searched for relevant studies. Meta-analyses of overall survival (OS) and clinicopathological features were conducted.

RESULTS

Ten studies were finally analyzed in the present study. High lncRNA GHET1 expression was associated with shorter OS than low lncRNA GHET1 expression in cancers (hazard ratio (HR) = 2.59, 95% CI = 1.93-3.47, P<0.01). Online cross-validation using The Cancer Genome Atlas (TCGA) data observed similar results (HR = 1.10, P<0.05). When compared with low lncRNA GHET1 expression, high lncRNA GHET1 expression was related to larger tumor size (P<0.01), worse differentiation (P<0.01), earlier distant metastasis (P=0.02), earlier lymph node metastasis (P<0.01) and more advanced clinical stage (P<0.01).

CONCLUSION

High lncRNA GHET1 expression is associated with worse cancer prognosis and can serve as a promising prognostic factor of human cancers.

MiR-7 reduces the BCSC subset by inhibiting XIST to modulate the miR-92b/Slug/ESA axis and inhibit tumor growth

BACKGROUND

Breast cancer stem cells (BCSCs) are typically seed cells of breast tumor that initiate and maintain tumor growth. MiR-7, as a cancer inhibitor, decreases the BCSC subset and inhibits tumor progression through mechanisms that remain unknown.

METHODS

We examined miR-7 expression in breast cancer and developed a BCSC-driven xenograft mouse model, to evaluate the effects of miR-7 overexpression on the decrease of the BCSC subset in vitro and in vivo. In addition, we determined how miR-7 decreased the BCSC subset by using the ALDEFLUOR, lentivirus infection, dual-luciferase reporter, and chromatin immunoprecipitation-PCR assays.

RESULTS

MiR-7 was expressed at low levels in breast cancer tissues compared with normal tissues, and overexpression of miR-7 directly inhibited lncRNA XIST, which mediates the transcriptional silencing of genes on the X chromosome, and reduced epithelium-specific antigen (ESA) expression by increasing miR-92b and inhibiting slug. Moreover, miR-7 suppressed CD44 and ESA by directly inhibiting the NF-κB subunit RELA and slug in breast cancer cell lines and in BCSC-driven xenografts, which confirmed the antitumor activity in mice injected with miR-7 agomir or stably infected with lenti-miR-7.

CONCLUSIONS

The findings from this study uncover the molecular mechanisms by which miR-7 inhibits XIST, modulates the miR-92b/Slug/ESA axis, and decreases the RELA and CD44 expression, resulting in a reduced BCSC subset and breast cancer growth inhibition. These findings suggest a potentially targeted treatment approach to breast cancer.

Long noncoding RNA XIST participates hypoxia-induced angiogenesis in human brain microvascular endothelial cells through regulating miR-485/SOX7 axis

BACKGROUND

Long non-coding RNAs (lncRNAs) X-inactive specific transcript (XIST) has identified to involve into the tumor cell angiogenesis. However, whether XIST contributes to Human Brain Microvascular Endothelial Cells (HBMEC) angiogenesis as well as potential mechanisms are largely unclear.

METHODS

The expression of XIST, miR-485-3p and SRY-box 7 (SOX7) in HBMEC were altered by transfection. The cell viability, cell migration and tube formation of HBMEC were measured, respectively. The cross-regulations between XIST, miR-485-3p, SOX7, and vascular endothelial growth factor (VEGF) signaling pathway were investigated by RT-qPCR and Western blot assay.

RESULTS

In this study, we characterized the upregulation of XIST in HBMEC under hypoxia condition. Meanwhile, XIST silencing impaired hypoxia-induced cell proliferation, migration and tube formation. Besides, our integrated experiments identified that XIST may competitively bind with miR-485-3p and then modulate the derepression of downstream target SRY-box 7 (SOX7). Mechanically, knockdown of XIST impaired hypoxia-induced angiogenesis via miR-485-3p/SOX7 axis and subsequent suppression of VEGF signaling pathway.

CONCLUSION

Altogether, the present study suggested that XIST is required to maintain VEGF signaling expression in HBMEC under hypoxia condition and plays a vital role in hypoxia-induced angiogenesis via miR-485-3p/SOX7 axis.

Down-regulation of lncRNA XIST inhibits cell proliferation via regulating miR-744/RING1 axis in non-small cell lung cancer

Long non-coding RNAs (lncRNAs) are known to be potential factors in promoting tumor progression. However, the function and mechanism of lncRNA XIST in non-small cell lung cancer (NSCLC) remains poorly understood. The expression levels of lncRNA XIST in NSCLC tissues and cell lines were detected with real-time PCR, and the correlation of the expression level of XIST with histopathological characteristics and prognosis was analyzed. The biological function of lncRNA XIST was validated through assays in vivo and in vitro The expression of lncRNA XIST was significantly up-regulated in NSCLC tissues. In addition, overexpression of XIST was positively correlated with the advanced clinical status of tumors, as well as poor overall survival and DFS. A tumor suppressive effect was presented via functional knockdown of lncRNA XIST. Up-regulation of XIST enhanced the proliferation, migration, and invasion ability of NSCLC cells both in vivo and in vitro Mechanically, it was indicated that XIST could serve as an endogenous competitive RNA modulating miR-744, leading to the miR-744/RING1 signaling pathway inhibition and Wnt/β-catenin signaling pathway activation. Taken together, it was confirmed here that XIST overexpression is associated with tumor progression phenotype and the newly discovered XIST/miR-744/RING1 axis, which could serve as a potential biomarker and therapeutic target for NSCLC.

Long non-coding RNA XIST predicting advanced clinical parameters in cancer: A Meta-Analysis and case series study in a single institution

Dysregulated expression of long non-coding RNA X-inactive specific transcript (lncRNA-XIST) has been indicated in various cancer types. In the present study, a meta-analysis was conducted to evaluate the potential role of lncRNA-XIST in predicting the clinicopathological parameters of patients with cancer. Eligible studies were obtained through a systematic search of PubMed, Web of Science, Embase and the Cochrane Library, of articles published prior to January 2019. The combined odds ratio and 95% confidence interval were calculated to determine the association between lncRNA-XIST expression and patient outcome. In addition, 45 pairs of osteosarcoma (OS) tissues and adjacent healthy tissues from a single institution were analyzed for the expression of lncRNA-XIST, and its association with clinicopathological features; ultimately, a total of 1,869 cancer patients from 25 studies were assessed. The results demonstrated that high expression levels of lncRNA-XIST were significantly associated with lymphatic metastasis, larger tumor size, advanced cancer stage and distant metastasis. However, sex was not associated with lncRNA-XIST expression level. In the OS patient cohort, it was demonstrated that lncRNA-XIST was highly expressed in OS tissues, which negatively correlated with patient prognosis. The present study indicated that lncRNA-XIST may serve as a potential biomarker for advanced clinical parameters in human cancer.

Prognostic value of long non-coding RNA ZEB1-AS1 in Chinese cancer patients: A Meta-analysis

BACKGROUND

Aberrant expression of long non-coding RNA Zinc finger E-box binding homeobox 1 antisense 1 (lncRNA ZEB1-AS1) can be detected in numerous malignancies. Therefore, a meta-analysis had been carried out in this study, aiming to examine the prognostic value of lncRNA ZEB1-AS1 in malignancies.

METHODS

Electronic databases, such as PubMed, OVID as well as Web of Science, had been systemically retrieved from inception to February 14th, 2019. Besides, the hazard ratios (HRs), together with the corresponding 95% confidence intervals (CIs), had also been analyzed for determining the association of lncRNA ZEB1-AS1 expression with the overall survival (OS) and recurrence-free survival (RFS). In addition, the pooled odds ratios (ORs) would also be computed using the Stata SE12.0 software for evaluating the relationship of lncRNA ZEB1-AS1 expression with pathological factors.

RESULTS

A total of 21 original studies involving 1801 cancer patients had been enrolled into the current meta-analysis. As suggested by the pooled HR, high expression of lncRNA ZEB1-AS1 had displayed marked correlation with OS (HR = 2.16, 95% CI: 1.89-2.47) among cancer patients, and no significant heterogeneity was detected. Additionally, high expression of lncRNA ZEB1-AS1 was also markedly associated with RFS among cancer patients (pooled HR = 2.55, 95% CI: 1.61-4.03). Besides, the expression of lncRNA ZEB1-AS1 had displayed marked correlation with poor histological grade (PHG) (OR = 2.86, 95% CI: 2.11-3.87), high tumor stage (HTS) (OR = 3.81, 95% CI: 2.72-5.34) as well as lymph node metastasis (LNM) (OR = 3.33, 95% CI: 2.47-4.49). Additionally, no distinct asymmetry had been detected for RFS, PHG as well as HTS based on Begg funnel plot.

CONCLUSIONS

Taken together, high expression of lncRNA ZEB1-AS1 can predict the dismal OS, RFS, LNM, PHG, and HTS, indicating that lncRNA ZEB1-AS1 can be potentially used as a new biomarker to predict the dismal prognosis for cancer patients.

Long non-coding RNA activated by TGF-β expression in cancer prognosis: A meta-analysis

BACKGROUND

Recently, long non-coding RNA activated by transforming growth factor beta (TGF-β) (lncRNA ATB) was shown to be useful in cancer prognosis, however, its prognostic value in human cancer has been inconsistent. Our study aimed to explore the prognostic role of lncRNA ATB expression in cancer prognosis.

METHODS

PubMed, Embase, and Cochrane Library databases were thoroughly searched to retrieve studies focusing on the prognostic role of lncRNA ATB expression in cancer, and meta-analysis was performed.

RESULTS

A total of 15 studies were included into this meta-analysis. High lncRNA ATB expression was significantly related to shorter overall survival (OS) (HR = 2.44, 95%CI = 1.98-3.01, P < 0.01), recurrence-free survival (RFS) (HR = 1.85, 95%CI = 1.42-2.40, P < 0.01), disease-free survival (DFS) (HR = 3.61, 95%CI = 2.45-5.33, P < 0.01), and progression-free survival (PFS) (HR = 2.97, 95%CI = 2.12-4.16, P < 0.01) when compared with low lncRNA ATB expression in cancer. Moreover, Patients with high lncRNA ATB expression tended to have worse tumor differentiation (P < 0.01), more advanced clinical stage (P < 0.01), deeper tumor invasion (P < 0.01), earlier distant metastases (P = 0.02), lymph node metastases (P = 0.04), and vascular invasion (P < 0.01) when compared with those with low lncRNA ATB expression.

CONCLUSIONS

High lncRNA ATB expression was significantly associated with worse prognosis in cancer. LncRNA ATB expression could be used as a prognostic biomarker for human cancer.