HMGI(Y) gene expression in colorectal cancer: comparison with some histological typing, grading, and clinical staging

Polypyrimidine tract-binding protein 3/insulin-like growth factor 2 mRNA-binding proteins 3/high-mobility group A1 axis promotes renal cancer growth and metastasis

Polypyrimidine tract-binding protein 3 (PTBP3) plays an important role in the post-transcriptional regulation of gene expression, including mRNA splicing, translation, and stability. Increasing evidence has shown that PTBP3 promotes cancer progression in several tumor types. However, the molecular mechanisms of PTBP3 in renal cell carcinoma (RCC) remain unknown. Here, tissue microarrays (TMAs) suggested that PTBP3 expression was increased in human RCC and that high PTBP3 expression was correlated with poor five-year overall survival and disease-free survival. We also showed that PTBP3 binds with HMGA1 mRNA in the 3'UTR region and let-7 miRNAs. PTBP3 interacted with IGF2BP3, and the PTBP3/IGF2BP3 axis prevented let-7 mediated HMGA1 mRNA silencing. PTBP3 promotes renal cancer cell growth and metastasis in vitro and in vivo. Taken together, our findings indicate PTBP3 serves as a regulator of HMGA1 and suggest its potential as a therapeutic agent for RCC.

LINC00665 target let-7i/HMGA1 promotes the proliferation and invasion of hepatoma cells

OBJECTIVES

Our group previously found that LINC00665 was upregulated in hepatocellular carcinoma (HCC) tissues through database analysis; however, the potential molecular mechanism of LINC00665 in HCC progression still needs further study.

METHODS

qRTPCR was performed to determine the differential expression of LINC00665 and let-7i in HCC cells. Dual-luciferase reporter assays were performed to analyze the interaction of LINC00665 and let-7i. CCK-8 assays, scratch assays, Transwell invasion assays, qRTPCR and western blotting were performed to determine the regulatory mechanism of LINC00665/let-7i/HMGA1 in HCC cells.

RESULTS

LINC00665 was upregulated in HCC cells compared with normal hepatocytes. A potential binding site between LINC00665 and let-7i was confirmed by dual-luciferase reporter assay. In HCC cells, inhibition of LINC00665 significantly reduced cell proliferation, migration and invasion ability via the let-7i/HMGA1 signaling axis.

CONCLUSION

LINC00665 promotes the proliferation and invasion of HCC cells via the let-7i/HMGA1 signaling axis.

Polymorphism and expression of the HMGA1 gene and association with tail fat deposition in Hu sheep

Hu sheep is an excellent short fat-tailed breed in China. Fat deposition in Hu sheep tail affects carcass quality and consumes a lot of energy, leading to an increase in feed cost. The objective of this study was to analyze the effects of HMGA1 polymorphism on tail fat weight in Hu sheep. Partial coding and non-coding sequences of HMGA1 were amplified with PCR and single nucleotide polymorphisms (SNP) of HMGA1 in 1163 Hu sheep were detected using DNA sequencing and KASPar technology. RT-qPCR analysis was performed to test HMGA1 expression in different tissues. The results showed that the expression of HMGA1 was higher in the duodenum, liver, spleen, kidney, and lung than in the heart, muscle, rumen, tail fat, and lymph. A mutation, g.5312 C > T, was detected in HMGA1; g.5312 C > T was significantly associated with tail fat weight, relative weight of tail fat (body weight), and relative weight of tail fat (carcass) (p < 0.05). The tail fat weight of the TT genotype was remarkably higher than that of the CC and TC genotypes. Therefore, HMGA1 can be used as a genetic marker for marker-assisted selection of tail fat weight in Hu sheep.

LncRNA ITGB2-AS1 promotes the progression of clear cell renal cell carcinoma by modulating miR-328-5p/HMGA1 axis

Clear cell renal cell carcinoma (ccRCC) is the most common histologic subtype of renal cell carcinoma and long non-coding RNAs (lncRNAs) play important roles in the progression of ccRCC. In this study, we aim to explore the potential function of ITGB2-AS1 in ccRCC progression and its underlying molecular mechanism. We first explored the association between ITGB2-AS1 expression level and ccRCC prognosis. We found that the expression level of ITGB2-AS1 was significantly higher in ccRCC tumor and cell lines, and highly expressed ITGB2-AS1 was also associated with a poorer prognosis. Consistently, silencing ITGB2-AS1 inhibited proliferation, promoted apoptosis in ccRCC cell lines, and curbed the tumorigenesis in the Xenograft model, reduced tumorigenesis in a xenograft tumor growth model. We further identified and confirmed the miRNA miR-328-5p as a target of ITGB2-AS1, and miR-328-5p negatively regulated the expression of HMGA1 protein. The anti-tumor effect of silencing ITGB2-AS1 could be partially rescued by inhibiting miR-328-5p activity or overexpressing HMGA1, indicating that ITGB2-AS1 promotes the survival and progression of ccRCC by modulating miR-328-5p/HMGA1 axis. Collectively, our data demonstrated that ITGB2-AS1 expression level is positively correlated with the survival and tumorigenesis of ccRCC. As a target of ITGB2-AS1, miR-328-5p seems to function as a tumor-suppressor, and the oncogenic effect of ITGB2-AS1 is partially mediated via the miR-328-5p/HMGA1 axis.

HMGA1 in cancer: Cancer classification by location

The high mobility group A1 (HMGA1) gene plays an important role in numerous malignant cancers. HMGA1 is an oncofoetal gene, and we have a certain understanding of the biological function of HMGA1 based on its activities in various neoplasms. As an architectural transcription factor, HMGA1 remodels the chromatin structure and promotes the interaction between transcriptional regulatory proteins and DNA in different cancers. Through analysis of the molecular mechanism of HMGA1 and clinical studies, emerging evidence indicates that HMGA1 promotes the occurrence and metastasis of cancer. Within a similar location or the same genetic background, the function and role of HMGA1 may have certain similarities. In this paper, to characterize HMGA1 comprehensively, research on various types of tumours is discussed to further understanding of the function and mechanism of HMGA1. The findings provide a more reliable basis for classifying HMGA1 function according to the tumour location. In this review, we summarize recent studies related to HMGA1, including its structure and oncogenic properties, its major functions in each cancer, its upstream and downstream regulation associated with the tumourigenesis and metastasis of cancer, and its potential as a biomarker for clinical diagnosis of cancer.

Clinicopathological and prognostic significance of HMGA2 overexpression in gastric cancer: a meta-analysis

Background

High mobility group protein A2 (HMGA2) overexpression has been reported to be closely related to tumor progression [1-4] and indicate significantly worse overall survival in gastric cancer [5-8]. However, a final consensus regarding this issue has not yet been reached. Thus, we conducted a meta-analysis to evaluate the association between HMGA2 expression and prognosis of gastric cancer patients.

Methods

The Cochrane Library, Embase, PubMed, Web of Science and China Biology Medicine databases were searched to identify eligible literature published prior to September 2016. In the included studies, the level of HMGA2 amplification was evaluated by immunohistochemistry. We performed a meta-analysis, and pooled relative risk (RRs), hazard ratio (HRs), and 95% confidence intervals (CIs) were analyzed using Review Manager 5.3.

Results

Six studies [5-7, 9-11] involving 712 gastric cancer patients were included and stratified by HMGA2 amplification magnitude. The results of the analysis indicated that higher HMGA2 levels were associated with several clinicopathological parameters and predicted poor prognosis in terms of overall survival (OS).

Conclusions

The results of the present study indicate that higher HMGA2 levels were significantly associated with TNM stage, lymph node status, vascular invasion, and poor OS in patients with gastric cancer. In conclusion, HMGA2 may serve as a promising prognostic biomarker in gastric cancer.

Phosphoproteomics Reveals HMGA1, a CK2 Substrate, as a Drug-Resistant Target in Non-Small Cell Lung Cancer

Although EGFR tyrosine kinase inhibitors (TKIs) have demonstrated good efficacy in non-small-cell lung cancer (NSCLC) patients harboring EGFR mutations, most patients develop intrinsic and acquired resistance. We quantitatively profiled the phosphoproteome and proteome of drug-sensitive and drug-resistant NSCLC cells under gefitinib treatment. The construction of a dose-dependent responsive kinase-substrate network of 1548 phosphoproteins and 3834 proteins revealed CK2-centric modules as the dominant core network for the potential gefitinib resistance-associated proteins. CK2 knockdown decreased cell survival in gefitinib-resistant NSCLCs. Using motif analysis to identify the CK2 core sub-network, we verified that elevated phosphorylation level of a CK2 substrate, HMGA1 was a critical node contributing to EGFR-TKI resistance in NSCLC cell. Both HMGA1 knockdown or mutation of the CK2 phosphorylation site, S102, of HMGA1 reinforced the efficacy of gefitinib in resistant NSCLC cells through reactivation of the downstream signaling of EGFR. Our results delineate the TKI resistance-associated kinase-substrate network, suggesting a potential therapeutic strategy for overcoming TKI-induced resistance in NSCLC.

Elevated expression of HMGA1 correlates with the malignant status and prognosis of non-small cell lung cancer

High-mobility group A1 (HMGA1) has been suggested to play a significant role in tumor progression, but little is known about the accurate significance of HMGA1 in non-small cell lung cancer (NSCLC) patients. The aim of this study was to identify the role of HMGA1 in NSCLC. The expression status of HMGA1 was observed initially in NSCLC by Gene Expression Omnibus (GEO). The expression of HMGA1 messenger RNA (mRNA) and protein was examined in NSCLC and adjacent normal lung tissues through real-time PCR and immunohistochemistry. Meanwhile, the relationship of HMGA1 expression levels with clinical features and prognosis of NSCLC patients was analyzed. In our results, HMGA1 was overexpressed in NSCLC tissues compared with adjacent normal lung tissues in microarray data (GSE19804). HMGA1 mRNA and protein expressions were markedly higher in NSCLC tissues than in normal lung tissues (P < 0.001 and P = 0.010, respectively). Using immunohistochemistry, high levels of HMGA1 protein were positively correlated with the status of clinical stage (I-II vs. III-IV, P < 0.001), T classification (T1-T vs. T3-T4, P = 0.003), N classification (N0N1 vs. N2-N3, P < 0.001), M classification (M0 vs. M1, P = 0.002), and differentiated degree (high or middle vs. low or undifferentiated, P = 0.003) in NSCLC. Patients with higher HMGA1 expression had a significantly shorter overall survival time than did patients with low HMGA1 expression. Multivariate analysis indicated that the level of HMGA1 expression was an independent prognostic factor (P < 0.001) for the survival of patients with NSCLC. In conclusion, HMGA1 plays an important role on NSCLC progression and prognosis and may act as a convictive biomarker for prognostic prediction.

Hmga1/Hmga2 double knock-out mice display a "superpygmy" phenotype

The HMGA1 and HMGA2 genes code for proteins belonging to the High Mobility Group A family. Several genes are negatively or positively regulated by both these proteins, but a number of genes are specifically regulated by only one of them. Indeed, knock-out of the Hmga1 and Hmga2 genes leads to different phenotypes: cardiac hypertrophy and type 2 diabetes in the former case, and a large reduction in body size and amount of fat tissue in the latter case. Therefore, to better elucidate the functions of the Hmga genes, we crossed Hmga1-null mice with mice null for Hmga2. The Hmga1(-/-)/Hmga2(-/-) mice showed reduced vitality and a very small size (75% smaller than the wild-type mice); they were even smaller than pygmy Hmga2-null mice. The drastic reduction in E2F1 activity, and consequently in the expression of the E2F-dependent genes involved in cell cycle regulation, likely accounts for some phenotypic features of the Hmga1(-/-)/Hmga2(-/-) mice.

Microarray analysis reveals that high mobility group A1 is involved in colorectal cancer metastasis

Tumor size indicates the extent of cell proliferation in most cases of colorectal cancer (CRC), although there are some advanced small tumors with metastases. Lymph node metastasis is a significant factor that greatly impacts disease prognosis in CRC cases. The underlying factors that cause lymph node metastasis in CRC cells are not fully understood. We investigated the mechanism that might induce CRC metastasis by focusing on smaller sized (<2 cm) invasive tumors. We carried out gene expression array analysis for CRC cases; group 1 consisted of 6 cases with tumors <2 cm with metastases, and group 2 consisted of 65 cases with tumors >2 cm without metastases. Results were validated using gene expression array data from an additional 77 cases and another bulk case set of 172 cases. Gene ontology and pathway analysis using microarray data revealed that anti-apoptotic activity had a crucial role in CRC metastasis. High mobility group A1 (HMGA1) was identified as a biomarker for poor prognosis and metastasis formation. HMGA1 expression levels were higher in lymph node-positive cases than in lymph node-negative cases, even in subgroup analysis of submucosal invasive cases. The present study strongly supports the clinical significance of HMGA1 expression as a predictive indicator of lymph node metastasis in CRC cases, even in submucosal invasive cases which could be cured by local resection.

Downregulation of HMGA2 by the pan-deacetylase inhibitor panobinostat is dependent on hsa-let-7b expression in liver cancer cell lines

Inhibitors of protein deacetylases represent a novel therapeutic option for cancer diseases due to their effects on transcriptional regulation by interfering with histones acetylation and on several other cellular pathways. Recently, their ability to modulate several transcription factors and, interestingly, also co-factors, which actively participate in formation and modulation of transcription complexes was shown. We here investigate whether HMGA2 (High Mobility Group AT-2 hook), a nuclear non-histone transcriptional co-factor with known oncogenic properties, can be influenced by the novel pan-deacetylase inhibitor panobinostat (LBH589) in human hepatocellular carcinoma models. Panobinostat strongly downregulated HMGA2 in HepG2 and Hep3B cells; this effect was mediated by transcriptional upregulation and promotion of the maturation of the tumorsuppressor miRNA hsa-let-7b, which could inhibit HMGA2 expression via RNA interference pathways. siRNA knockdown of HMGA2 or transfection of hsa-let-7b mimicking oligonucleotides confirmed the role of HMGA2 in regulating cell proliferation and apoptosis in liver cancer cell lines. Co-incubation with panobinostat showed an additive effect on inhibition of cell proliferation using an impedance-based real-time cell analyzer. Treatment of HepG2 xenografts with panobinostat also led to a downregulation of HMGA2 in vivo. These findings show that pan-deacetylase inhibitors also modulate other signaling pathways and networks than histone modifications to influence cell fate.

Overexpression of HMGA1 deregulates tumor growth via cdc25A and alters migration/invasion through a cdc25A-independent pathway in medulloblastoma

Overexpression of high mobility group AT-hook 1 (HMGA1) is common in human cancers. Little is known about the mechanisms underlying its deregulation and downstream targets, and information about its clinical and biological significance in medulloblastoma (MB) is lacking. Here, we demonstrated frequent genomic gain at 6p21.33-6p21.31 with copy number increase leading to overexpression of HMGA1 in MB. The overexpression correlated with a high proliferation index and poor prognosis. Moreover, we found that hsa-miR-124a targeted 3'UTR of HMGA1 and negatively modulated the expression in MB cells, indicating that loss/downregulation of hsa-miR-124a reported in our previous study could contribute to the overexpression. Regarding the biological significance of HMGA1, siRNA knockdown and ectopic expression studies revealed the crucial roles of HMGA1 in controlling MB cell growth and migration/invasion through modulation of apoptosis and formation of filopodia and stress fibers, respectively. Furthermore, we identified cdc25A as a target of HMGA1 and showed that physical interaction between HMGA1 and the cdc25A promoter is required for transcriptional upregulation. In clinical samples, HMGA1 and cdc25A were concordantly overexpressed. Functionally, cdc25A is involved in the HMGA1-mediated control of MB cell growth. Finally, netropsin, which competes with HMGA1 in DNA binding, reduced the expression of cdc25A by suppression of its promoter activity and inhibited in vitro and in vivo intracranial MB cell growth. In conclusion, our results delineate the mechanisms underlying the deregulation and reveal the functional significance of HMGA1 in controlling MB cell growth and migration/invasion. Importantly, the results highlight the therapeutic potential of targeting HMGA1 in MB patients.

Increased expression of HMGA1 correlates with tumour invasiveness and proliferation in human pituitary adenomas

AIMS

High-mobility group A1 (HMGA1) is highly expressed in various benign and malignant tumours. The development of pituitary adenoma in Hmga1 transgenic mice has been reported. However, no studies have investigated HMGA1 expression and its clinical significance in human pituitary adenomas.

METHODS AND RESULTS

Immunohistochemical expression of HMGA1 was analysed with respect to various clinicopathological factors in 95 pituitary adenomas. Nuclear expression of HMGA1 was observed in 62% of pituitary adenomas, whereas normal adenohypophysial tissues were negative. Although HMGA1 expression was frequently detected in clinically non-functioning adenomas - 90% of silent adrenocorticotropic hormone (ACTH), 76.2% of follicle-stimulating hormone/luteinizing hormone and 100% of null cell adenomas - it was also detected in 48.1% of growth hormone (GH), 60% of mixed GH/prolactin (PRL), 62.5% of PRL, 66.6% of thyroid-stimulating hormone and 37.5% of ACTH adenomas. HMGA1 expression was significantly higher in invasive adenomas or macroadenomas than in non-invasive adenomas or microadenomas (invasive versus non-invasive, P < 0.05; macroadenoma versus microadenoma, P < 0.05). In addition, HMGA1 showed the highest level in grade IV, more aggressive pituitary adenomas, than in grades I, II and III (IV versus I, P = 0.01; IV versus II, P = 0.01; IV versus III, P = 0.07). Furthermore, a significant correlation between HMGA1 expression and MIB-1 labelling index was observed (R = 0.368, P < 0.0002).

CONCLUSIONS

These findings suggest that HMGA1 up-regulation has an important oncogenic role in pituitary tumorigenesis, as well as being a novel molecular marker of tumour proliferation and invasiveness.

Gene expressions of HMGI-C and HMGI(Y) are associated with stage and metastasis in colorectal cancer

PURPOSE

The high mobility group proteins (HMGs) include the HMGI family members HMGI-C and HMGI(Y), whose expressions in adult tissues generally correlate with malignant tumor phenotypes. The aim of this study was to assess the relationship of HMGI-C or HMGI(Y) gene expression and prognosis in colorectal cancer patients.

METHODS

The gene expressions of HMGI-C and HMGI(Y) in 31 paired samples of colorectal tumor and corresponding non-tumor were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

The expression of HMGI(Y) in a colorectal cancer tumor was associated with Dukes staging (p = 0.044), while, in non-tumor, the expression of this gene was significant with metastasis (p = 0.003). Patients with Dukes stage A and B present high HMGI(Y) expression in non-tumor of colorectal cancer (p = 0.006). However, patients with Dukes stage C and D present high HMGI-C expression in colorectal tumor (p = 0.023). In the non-metastasis group, HMGI(Y) was highly expressed in non-tumor of colorectal cancer. However, in the metastasis group, there was no significant difference between tumor and non-tumor tissues in both HMGI-C and HMGI(Y) gene expressions.

CONCLUSIONS

The HMGI-C and HMGI(Y) quantitations by real-time RT-PCR are associated with Dukes staging and metastasis; hence, the gene expression levels may be useful in clinical practice.

HMGA1 is a molecular determinant of chemoresistance to gemcitabine in pancreatic adenocarcinoma

PURPOSE

HMGA1 proteins are architectural transcription factors that are overexpressed by pancreatic adenocarcinomas. We previously have shown that RNA interference targeting the HMGA1 gene may represent a potential chemosensitizing strategy in pancreatic adenocarcinoma cells. In this study, we tested the hypothesis that HMGA1 promotes chemoresistance to gemcitabine in pancreatic cancer cells.

EXPERIMENTAL DESIGN AND RESULTS

Stable short hairpin RNA-mediated HMGA1 silencing in BxPC3 and MiaPaCa2 cells promoted chemosensitivity to gemcitabine, with reductions in gemcitabine IC(50) and increases in gemcitabine-induced apoptosis and caspase-3 activation. In contrast, forced HMGA1 overexpression in MiaPaCa2 cells promoted chemoresistance to gemcitabine, with increases in gemcitabine IC(50) and reductions in gemcitabine-induced apoptosis and caspase-3 activation. Dominant negative Akt abrogated HMGA1 overexpression-induced increases in chemoresistance to gemcitabine. Finally, HMGA1 silencing promoted chemosensitivity to gemcitabine in vivo in a nude mouse xenograft model of pancreatic adenocarcinoma.

CONCLUSION

Our findings suggest that HMGA1 promotes chemoresistance to gemcitabine through an Akt-dependent mechanism. Targeted therapies directed at HMGA1 represent a potential strategy for ameliorating chemoresistance in pancreatic adenocarcinoma.

Roles of HMGA proteins in cancer

The high mobility group A (HMGA) non-histone chromatin proteins alter chromatin structure and thereby regulate the transcription of several genes by either enhancing or suppressing transcription factors. This protein family is implicated, through different mechanisms, in both benign and malignant neoplasias. Rearrangements of HMGA genes are a feature of most benign human mesenchymal tumours. Conversely, unrearranged HMGA overexpression is a feature of malignant tumours and is also causally related to neoplastic cell transformation. Here, we focus on the role of the HMGA proteins in human neoplastic diseases, the mechanisms by which they contribute to carcinogenesis, and therapeutic strategies based on targeting HMGA proteins.

Overexpression of HMGA1 promotes anoikis resistance and constitutive Akt activation in pancreatic adenocarcinoma cells

HMGA1 proteins are architectural transcription factors that are overexpressed by pancreatic adenocarcinomas. Roles of HMGA1 in mediating the malignant phenotype of this cancer are poorly understood. We tested the hypothesis that overexpression of HMGA1 promotes resistance to anoikis (apoptosis induced by anchorage deprivation) in pancreatic cancer cells. HMGA1 cDNA was stably transfected into MiaPaCa2 human pancreatic adenocarcinoma cells (which have low baseline expression levels of HMGA1). Cells were grown in suspension on PolyHEMA-coated plates and their susceptibility to anoikis was assayed using flow cytometry. Overexpression of HMGA1 was associated with marked reductions in susceptibility to anoikis in concert with increases in Akt phosphorylation (Ser473) and in Akt kinase activity and with reductions in caspase 3 activation. Inhibition of phosphoinositidyl-3 (PI3-K)/Akt pathway with either the small molecule inhibitor LY294002 or dominant-negative Akt resulted in reversal of anoikis resistance induced by HMGA1 overexpression. Further, RNA interference-mediated HMGA1 silencing in MiaPaCa2 and BxPC3 (a human pancreatic adenocarcinoma cell line with high baseline levels of HMGA1 expression) cells resulted in significant increases in susceptibility to anoikis. Our findings suggest HMGA1 promotes anoikis resistance through a PI3-K/Akt-dependent mechanism. Given the putative associations between anoikis resistance and metastatic potential, HMGA1 represents a potential therapeutic target in pancreatic adenocarcinoma.

HMGA1 is a determinant of cellular invasiveness and in vivo metastatic potential in pancreatic adenocarcinoma

HMGA1 proteins are architectural transcription factors that are overexpressed in a range of human malignancies, including pancreatic adenocarcinoma. We hypothesized that HMGA1 expression is a determinant of cellular invasiveness and metastasis in pancreatic cancer. Stable silencing of HMGA1 in MiaPaCa2 and PANC1 pancreatic adenocarcinoma cells was achieved by transfection of short hairpin RNA-generating vectors. Additionally, stable overexpression of HMGA1 in MiaPaCa2 cells (characterized by low levels of inherent HMGA1 expression) was achieved. HMGA1 silencing resulted in significant reductions in cellular invasiveness through Matrigel; in cellular matrix metalloproteinase-9 (MMP-9) activity, mRNA levels, and gene promoter activity; and in Akt phosphorylation at Ser(473). Conversely, forced HMGA1 overexpression resulted in significant increases in cellular invasiveness; in cellular MMP-9 activity, mRNA levels, and promoter activity; and in Akt phosphorylation at Ser(473). HMGA1 overexpression-induced increases in invasiveness were MMP-9 dependent. The role of phosphatidylinositol-3 kinase (PI3K)/Akt in mediating HMGA1-dependent invasiveness was elucidated by a specific PI3K inhibitor (LY294002) and constitutively active and dominant-negative Akt adenoviral constructs. Akt-dependent modulation of MMP-9 activity contributed significantly to HMGA1 overexpression-induced increases in invasive capacity. Furthermore, HMGA1 silencing resulted in reductions in metastatic potential and tumor growth in vivo and in tumoral MMP-9 activity. Our findings suggest that HMGA1 may be a novel molecular determinant of invasiveness and metastasis, as well as a potential therapeutic target, in pancreatic adenocarcinoma.

Cyclin D1 protein and CCND1 gene expression in colorectal cancer

AIMS

To report the expression of cyclin D1 protein and its gene in a series of colorectal adenocarcinoma.

METHODS

One hundred and eleven specimens of colorectal carcinomas and adjacent normal colorectal mucosa were investigated by staining with a monoclonal antibody against cyclin D1 and by RT-PCR.

RESULTS

Expression of CCND1 gene was found in 54 out of 111 cases of colorectal cancers, while in normal mucosa the expression of this gene was not observed. Cyclin D1 protein expression was checked in the same group of adenocarcinoma cases. Presence of this protein was observed in 69 cases and for 43 of them also expression of its gene was found. Dependence between the presence of protein and the gene expression was statistically significant (p=0.0002). In the group of cases where CCND1 gene expression was detected, high level of its protein expression was found in 20 cases. The CCND1 gene expression was associated with metastases to lymph nodes (p=0.0181) and also with distant metastasis (p=0.0204).

CONCLUSIONS

The combined measurement of both the gene and its protein product, is an important contribution to the study of molecular markers in histological material.