Colorectal cancers with microsatellite instability display mRNA expression signatures characteristic of increased immunogenicity
© Banerjea et al; licensee BioMed Central Ltd. 2004
Received: 17 May 2004
Accepted: 06 August 2004
Published: 06 August 2004
Colorectal cancers displaying high-degree microsatellite instability (MSI-H) have an improved prognosis compared to microsatellite stable (MSS) cancers. The observation of pronounced lymphocytic infiltrates suggests that MSI-H cancers are inherently more immunogenic. We aimed to compare the gene expression profiles of MSI-H and MSS cancers to provide evidence for an activated immune response in the former.
We analysed tissue from 133 colorectal cancer patients with full consent and Local Ethics Committee approval. Genomic DNA was analysed for microsatellite instability in BAT-26. High-quality RNA was used for microarray analysis on the Affymetrix® HG-U133A chip. Data was analysed on GeneSpring software version 6.0. Confirmatory real-time RT-PCR was performed on 28 MSI-H and 26 MSS cancers. A comparison of 29 MSI-H and 104 MSS cancers identified 2070 genes that were differentially expressed between the two groups [P < 0.005]. Significantly, many key immunomodulatory genes were up-regulated in MSI-H cancers. These included antigen chaperone molecules (HSP-70, HSP-110, Calreticulin, gp96), pro-inflammatory cytokines (Interleukin (IL)-18, IL-15, IL-8, IL-24, IL-7) and cytotoxic mediators (Granulysin, Granzyme A). Quantitative RT-PCR confirmed up-regulation of HSP-70 [P = 0.016], HSP-110 [P = 0.002], IL-18 [P = 0.004], IL-8 [0.002] and Granulysin [P < 0.0001].
The upregulation of a large number of genes implicated in immune response supports the theory that MSI-H cancers are immunogenic. The novel observation of Heat Shock Protein up-regulation in MSI-H cancer is highly significant in light of the recognised roles of these proteins in innate and antigen-specific immunogenicity. Increased mRNA levels of pro-inflammatory cytokines and cytotoxic mediators also indicate an activated anti-tumour immune response.
Colorectal cancer remains a leading cause of cancer death in the Western world despite recent advances in surgery, radiotherapy and chemotherapy . Immunotherapy has attracted attention as a novel treatment modality that may exploit the host immune response against tumour cells. However, definitive evidence that colorectal cancer cells can stimulate a specific immune response has been elusive.
Approximately 15–20% of sporadic colorectal cancers and nearly all large bowel malignancies in the Hereditary Non-Polyposis Colorectal Cancer (HNPCC) syndrome are characterised by widespread microsatellite instability [2, 3]. Microsatellites are very short repetitive nucleotide sequences, distributed throughout the human genome, that are prone to insertion and deletion mutations during DNA replication. These mutations are normally corrected by the inherent proofreading capacity of DNA polymerase and a group of genes involved in mismatch repair (MMR). Defective mismatch repair allows the accumulation of errors in microsatellites and this is termed microsatellite instability (MSI). In HNPCC a germline mutation in a mismatch repair gene is inherited and a subsequent "second hit" leads to failure of MMR, resulting in MSI. In sporadic cancers epigenetic silencing by hypermethylation of the MMR genes has been implicated. Despite these differences in their molecular genesis the two groups share common clinicopathological features . Several studies have confirmed that patients with tumours displaying a high degree of microsatellite instability (MSI-H) appear to possess a survival advantage over those with cancers that are microsatellite stable (MSS) [5–7]. This improvement in outcome appears to be an inherent feature of the unstable phenotype.
It has been shown that MSI-H cancers generate abnormal peptides that can be used to excite cytotoxic T cell responses in in vitro experiments [8, 9]. These peptides may act as Tumour specific antigens (TSA's) in vivo and hence, excite a host immune response. In keeping with this observation MSI-H cancer is characterised by the presence of a significant infiltrate of lymphocytes, a feature that has been previously associated with better patient prognosis . Lymphocytes that infiltrate tumour epithelium (intra-epithelial lymphocytes, IEL's) are specifically associated with improved survival and may be involved in an immune response . Immunohistochemical analyses have shown that the IEL's infiltrating MSI-H colorectal cancers are predominantly cytotoxic, activated and release mediators of target cell death . Follow-up analyses confirm improved survival in patients with these tumours . Increased apoptosis has also been demonstrated in MSI-H cancers but the link between increased lymphocyte infiltrate and apoptotic cell death has not yet been proven. Some argue that these infiltrates are secondary phenomena with no biological relevance  and it has been suggested that intra-epithelial lymphocyte populations in MSI-H colorectal cancers simply represent proliferation of resident lamina propria lymphocytes with no immunological activation or role.
The development of high-density data analysis techniques such as microarray technology allows rapid gene expression profiling of tissue-derived RNA to give an mRNA expression signature for the tissue under study. The gene expression signature of a tumour microenvironment reflects the interactions between tumour, stroma and host response therein. We aimed to compare these signatures between groups of MSI-H and MSS colorectal cancers to identify genes that are differentially expressed between the two phenotypes. Specifically, we focus on genes involved in anti-tumour immune responses whose activity may be modified in colorectal cancers, in order to clarify the nature of any immune response in MSI-H colorectal cancer.
Summary of patient demographics for microarray and RT-PCR analyses.
Microsatellite Stable (MSS)
Microsatellite Unstable (MSI-H)
Mean age (SD) (yrs)
Male: Female (%)
Right: Left (%)
Dukes' Stage A (%)
Lymphocyte score 1(%)
Mean age (SD) (yrs)
Male: Female (%)
Right: Left (%)
Dukes' Stage A (%)
An initial comparison of the gene expression profiles of MSI-H versus MSS tumours, using a parametric unpaired t-test (with Welch's correction for unequal variances) and the Benjamini and Hochberg False Discovery Rate (multiple correction method), identified 2070 genes that were differentially expressed at a significance of p < 0.005 (Additional Table 1). This represents 9.3% of those included on the chip and statistically less than 0.5% of these genes would be selected by chance. 1293 genes (62.5%) had significantly increased signal intensity in MSI-H cancers and 777 genes (37.5%) had reduced signal intensity.
A highly selective list of gene specific probes that are differentially expressed (P < 0.005) between MSI-H and MSS colorectal cancers with a fold-change of at least 1.5.
Genes Up-regulated in MSI-H Colorectal Cancer
Catenin (cadherin assoc. protein) beta 1
6.5 × 10-12
1.7 × 10-4
1.3 × 10-7
6.0 × 10-8
Heat shock protein (HSP 110 family)*
2.4 × 10-5
TP53 (Li Fraumeni)*
2.5 × 10-4
Toll-like receptor 2 (TLR-2)
1.9 × 10-4
Heat shock protein 70*
3.5 × 10-6
2.9 × 10-5
Human Natural killer Cell enhancing factor
4.8 × 10-4
ICAM 1 (CD54)
Interleukin 18 (interferon-gamma inducing factor)*
4.6 × 10-4
Genes down-regulated in MSI-H colorectal cancer
Insulin-like growth factor 2 (somatomedin A)
1.9 × 10-5
9.3 × 10-5
6.7 × 10-5
Our study examines the differences in overall gene expression profiles in the tumour micro-environments of MSI-H and MSS colorectal cancers. The observation that a large number of pro-inflammatory genes are upregulated in MSI-H colorectal cancer is a strong indicator that an immune response is indeed activated in these tumours. These results support the notion that the lymphocytic infiltrates in these cancers represent immune activation rather than simple proliferation of resident lymphocytes.
The exact nature of the immune response remains unclear but our novel observation that heat shock proteins are upregulated in MSI-H colorectal cancer may be highly significant. Microarray data analysis demonstrated that several members of the HSP family are up-regulated in MSI-H cancers (Table 2) and RT-PCR analyses confirmed increased levels of both HSP-110 and HSP-70 mRNA in our MSI-H cancers. Heat shock proteins have roles in both innate and adoptive immunity and have excited much interest as natural adjuvants for immunotherapy [15, 16]. Some members of the HSP family act directly to excite an innate immune response that might be more marked in MSI-H colorectal cancer. Such a response might be mediated by Natural Killer cells that characteristically release Granulysin to induce tumour cell death, a recognised feature of MSI-H colorectal cancer, which in turn releases intra-cellular TSA's. Alternatively, the concept of "effete malignancy", in which accumulation of mismatch errors overwhelms the tumour cells' viability,  may explain increased tumour cell death and release of TSA's. In fact, these two possible explanations of increased apoptosis in MSI-H colorectal cancers may actually be complementary rather than mutually exclusive. However, the release of TSA's into the tumour micro-environment is the pivotal step in the generation of an antigen-specific immune response.
Heat shock proteins act as chaperone proteins in the processing and presentation of antigenic peptides [15, 16]. They promote antigen uptake and induce expression of antigen presenting and co-stimulatory molecules on dendritic cells. By example, HSP-70 has been shown to recruit dendritic cells (and T cells) and enhances their ability to uptake antigen . This is a crucial step in the cross-priming of dendritic cells necessary for an antigen-directed immune response . The CD68 antigen, expressed by immature dendritic cells and macrophages that are ready to take up antigen, is included in our list of genes up-regulated in MSI-H colorectal cancer, as is the TLR-2 gene, one of a family of receptors to which HSP's bind to activate dendritic cells.
Heat Shock Proteins have also been shown to induce cytokine profiles that promote antigen-specific responses. This role may underscore our observation that several immunogenic interleukins are up-regulated in MSI-H cancers. An important function of these cytokines is to promote the presentation of antigen by dendritic cells (and macrophages) to effector T cells. This represents another crucial step in the development of an antigen-specific immune response, prior to the interaction of primed cytotoxic (CD8+) and helper (CD4+) T cells with the tumour cells. This interaction subsequently results in lytic tumour cell death. Specifically, such cytokines also modulate which arm of the T helper system is activated: Th1 activity favours immune activity whilst Th2 pathways favour tolerance. In this context, our data reveals significant up-regulation of IL-18 and other pro-inflammatory cytokines in MSI-H cancers that promote Th1 activity.
Our microarray data are validated by the existing knowledge of key gene expression in MSI-H colorectal cancers. The presence of hMLH1 mRNA was reduced in MSI-H cancers, as shown by both microarray and RT-PCR analyses. This observation reflects the fact that hMLH1 is frequently silenced, due to promoter region hypermethylation, in sporadic cancers, which formed the majority of our MSI-H group. Other genes known to be affected by the MSI pathway such as TGFβ RII, IGFIIR, TP53, APC, β catenin and Bcl-2 were also differentially expressed between our two groups [20, 21]. The inclusion of HNPCC cancers within our MSI-H group appears not to affect the differentially expressed genes we identify and this is likely to reflect their small number. Accrual of further HNPCC gene expression profiles should allow us to sub-analyse the MSI-H group in the future. However, the immunological focus of this paper appears unaffected by any differences in the biology of these cancers.
Additional genes related to apoptosis and the Major Histocompatibility Complex shown to be up-regulated in MSI-H colorectal cancer in comparison to MSS cancers.
Apoptosis related genes up-regulated in MSI-H colorectal cancers (P < 0.005, Benjamini and Hochberg False Discovery Rate)
Tumour necrosis factor receptor superfamily 10d
Tumour necrosis factor receptor superfamily 9
Tumour necrosis factor receptor superfamily 10b
Tumour necrosis factor receptor superfamily 6
Death-associated protein kinase 1
DNA fragmentation factor, beta polypeptide (caspase-activated DNase)
Bcl-2-related protein A1
Bcl-2/adenovirus E1B 19 kDa interacting protein 3-like
Bcl-2 associated athanogene 3
Bcl-2/adenovirus E1B 19 kDa interacting protein 1
Baculoviral IAP repeat-containing 3
Baculoviral IAP repeat-containing 2
Chemokine (C-X-C motif) receptor 4
CD27-binding (Siva) protein
Thioredoxin-like, 32 kDa
Mitogen-activated protein kinase kinase kinase 5
Microtubule associated protein tau
Macrophage erythroblast attacher
Testis enhanced gene transcript (BAX inhibitor 1)
Major histocompatibility complex-related genes up-regulated in MSI-H colorectal cancer (P < 0.05, Benjamini and Hochberg False Discovery Rate)
Major histocompatibility complex, class II, DR alpha
Major histocompatibility complex, class II, DQ beta 1
Major histocompatibility complex, class II, DP alpha 1
H. sapiens HLA-DMA gene
Major histocompatibility complex, class II, DR beta 1
Major histocompatibility complex, class II, DR beta 5
HLA-B associated transcript 1
Major histocompatibility complex, class I, C
It is of interest that reduction of the stringency of our statistical comparison to P < 0.05 (Benjamini and Hochberg False Discovery Rate) generates a list of 4788 differentially expressed genes (Additional Table 1). These include several more genes with key immunomodulatory functions. Transcripts specific to co-stimulatory molecules (CD80 and CD86), HSP60, MHC peptides, pro-inflammatory cytokine receptors, Perforin 1 and Caspase 9 were amongst those that were up-regulated in MSI-H colorectal cancers. These subsidiary data provide further evidence that these cancers excite an antigen-specific immune response. Closer study of HLA molecules that were up-regulated in MSI-H cancers reveals that the majority are Class II-related (Table 3). This finding is consistent with previous studies [24, 25] and supports the notion that immunogenicity of these cancers relies on antigen presentation by Antigen Presenting Cells (cross-priming) rather than directly by the tumour. The HLA Class I molecule β2-microglobulin has been shown to be a target for mutation in the MSI-H pathway and this renders HLA Class I machinery ineffective in these tumours . This gene does not, however, appear in our list of differentially expressed genes.
This study compares gene expression profiles in 133 primary human cancers and confirms the previous finding on a smaller sample set that microarray profiling can differentiate cancers according to microsatellite stability status . A recent report on differential gene expression from microarray profiling of smaller numbers of MSI-H (n = 8) and MSS (n = 14) colorectal cancer tissue samples yielded findings similar to ours in genes such as TP53, IGF2, RAN, MORF4L1, ZFP36L2 and CCNF . Their observation that EIF3S2 is downregulated in MSI-H was confirmed in our study, as was the downregulation of TGFβ RII. However, they did not observe differences in MMR genes, such as hMLH1 and PMS2, or indeed the immunomodulatory genes that we report. The likely explanation is that the smaller sample numbers used in their analysis as well as the smaller size of their spotted cDNA array (8000 genes) limits the sensitivity of their microarray comparisons. Previously two groups have reported the results of cDNA microarray comparisons of MSI-H and MSS cancer cell lines but both were restricted to very small numbers [29, 30]. Interestingly, of the 122 differentially expressed genes identified by these two studies 33 transcripts (27%) were also included in our list of 4788 genes (P < 0.05, Benjamini and Hochberg False Discovery Rate). However, some genes noted to be down-regulated in MSI-H cancer cell lines were up-regulated in the MSI-H cancers in our analysis, and vice versa. These disparities can be attributed to the fact that cancer cells cultured in vitro behave differently to cells from primary tumours. Indeed Bertucci et al report that colorectal cancer lines show overexpression of genes involved in cellular proliferation and underexpression of several gene clusters, including a cluster associated with immunomodulatory genes, when compared to colorectal cancer tissue samples using microarrays . These biological differences and the small numbers used in the cell line experiments render any concordance between our data and cell line analyses altogether encouraging.
We acknowledge that mRNA profiles cannot be presumed to reflect functional significance at a protein level. However, the upregulation of such a large number of genes, known to be involved in innate and antigen-specific immune responses, in MSI-H colorectal cancer indicates a genuine difference in host-tumour interactions. These findings are entirely novel and add considerable weight to the argument that MSI-H cancers excite an immune response. Clearly, additional work on protein expression specific to the genes we have identified will help to elucidate the exact nature of immune mechanisms in these cancers.
In this study microdissection was deliberately eschewed as our focus was the interaction between tumour, stroma and inflammatory cells and the expression profiles therefore reflect contributions from each of these groups. Microdissection would have excluded the contribution of certain cell populations which may have important roles in the modulation of host-tumour interactions. We have previously extensively analysed the composition of tumour biopsies obtained by sampling exophytic areas of resected specimens. We consistently found that a random sample taken from a fresh frozen segment of tumour tissue contained at least 80% tumour cells (Unpublished data). We know from experience that necrotic tumour does not yield high quality RNA and our study included only those samples that yielded high quality RNA and thus, the sampling technique we used inherently excludes necrotic tumour. It is therefore unlikely that our results are attributable to the presence of tumour necrosis. Furthermore, a DNA microarray analysis of the gene expression profiles of naïve versus activated tumour-specific lymphocytes did not show differences of gene expression in heat shock proteins or the interleukins noted in our study . This suggests that our observations do not simply reflect the more pronounced lymphocyte infiltrates of MSI-H colorectal cancer although we accept that this remains a possibility.
Certainly, our results provide new evidence to support the notion that MSI-H colorectal cancers are immunogenic and new insights into the pathways that may be involved. Further focussed study of these cancers may clarify the immunology of colorectal cancer and, specifically, may provide useful targets for directing immunotherapeutic strategies.
Patient population and microsatellite analysis
The Local Ethics Committee approved this study and all patients gave informed consent prior to surgery. Tissue was available from a bank of 223 colorectal cancers resected at The Royal London Hospital between December 1997 and March 2003. Tissue samples of tumour and normal mucosa were taken within 20 minutes of resection and snap frozen in liquid nitrogen. Normal mucosa and tumour DNA was extracted and used in PCR reactions to amplify the mononucleotide BAT-26 marker, as described elsewhere . Products were separated and visualised on micro-fabricated chips to identify tumours displaying bandshifts characteristic of a high degree of microsatellite instability .
Microarray profiling and analysis
Total RNA was prepared from samples using an RNeasy® kit (QIAGEN, Hilden, Germany) and quality was assessed on the Agilent Bioanalyser 2100. Only 129 samples, from our tumour bank, that yielded high quality mRNA with minimal degradation and clear 18S/28S ribosomal peaks, were included in the analysis. Preparation of in vitro transcription (IVT) products, oligonucleotide array hybridization and scanning were performed according to Affymetrix® (Santa Clara, California) protocols. In brief, 5 μg of total RNA from each colon tumour and T7-linked oligo-dT primers were used for first-strand cDNA synthesis. IVT reactions were performed in batches to generate biotinylated cRNA targets, which were chemically fragmented at 95°C for 35 minutes. Fragmented biotinylated cRNA (10 μg) was hybridized at 45°C for 16 hours to Affymetrix® high density oligonucleotide array human HG-U133A chip, which contains 22,283 probe sets representing more than 14,500 well-substantiated human genes. The arrays were washed and stained with streptavidin-phycoerythrin (SAPE, final concentration of 10 μg/ml). Signal amplification was performed using a biotinylated anti-streptavidin antibody. The array was scanned according to the manufacturer's instructions (Affymetrix Genechip® Technical Manual, 2001). Scanned images were inspected for the presence of obvious defects (artefacts or scratches) on the array. Defective chips were excluded and the sample was re-analysed. To minimize discrepancies due to variables such as sample preparation, hybridization conditions, staining, or array lot, the raw expression data was scaled using Affymetrix® Microarray Suite 5.0 software. The trimmed mean signal of all probe sets on the HG-U133A chip was adjusted to a user-specified target signal value (1500) for each array for global scaling. No specific exclusion criteria were applied.
Comparative analysis between expression profiles for MSI-H and MSS samples was carried out on GeneSpring™ software version 6.0 (Silicongenetics, Redwood, California). The "Cross gene error model for deviation from 1.0" was active. Gene expression data was normalised in two ways: "per chip normalisation" and "per gene normalisation". For "per chip normalisation" all expression data on a chip is normalised to the 50th percentile of all values on that chip. For "per gene normalisation" the data for a given gene is normalised to the median expression level of that gene across all samples. The data sets are then assigned to the two groups MSI-H and MSS, and the expression profiles of the two groups were compared using unpaired t-tests (with Welch's correction for unequal variances) and multiple testing corrections to identify genes that were differentially expressed between them.
Summary of RT-PCR details and the numbers of samples in each analysis. Analysis of hMLH1, IL-15 and Caspase2 restricted to smaller numbers due to limited availability of high-quality RNA.
Chemistry (Applied Biosystems, Warrington, UK)
Sample Numbers (n)
High-Capacity cDNA Archive Kit + TaqMan Universal PCR Master Mix (with AmpErase UNG)
TaqMan® EZ-RT-PCR Kit
HSP-70 kD 1B
TaqMan® EZ-RT-PCR Kit
TaqMan® EZ-RT-PCR Kit
TaqMan® EZ-RT-PCR Kit
TaqMan® EZ-RT-PCR Kit
High-Capacity cDNA Archive Kit + TaqMan Universal PCR Master Mix (with AmpErase UNG)
TaqMan® EZ-RT-PCR Kit
TaqMan® EZ-RT-PCR Kit
List of abbreviations
High degree microsatellite instability
Microsatellite stable (including low degree instability)
This work was funded by MRC Grant (G0000141) and Bowel and Cancer Research (Registered Charity No. 328667). Funding sources had no influence over study design, data collection, analysis or interpretation or manuscript preparation and submission.
- Boyle P, Leon ME: Epidemiology of colorectal cancer. Br Med Bull. 2002, 64: 1-25. 10.1093/bmb/64.1.1View ArticlePubMedGoogle Scholar
- Ionov Y, Peinado MA, Malkhosyan S, Shibata D, Perucho M: Ubiquitous somatic mutations in simple repeated sequences reveal a new mechanism for colonic carcinogenesis. Nature. 1993, 363: 558-561. 10.1038/363558a0View ArticlePubMedGoogle Scholar
- Aaltonen LA, Peltomaki P, Leach FS, Sistonen P, Pylkkanen L, Mecklin JP, Jarvinen H, Powell SM, Jen J, Hamilton SR: Clues to the pathogenesis of familial colorectal cancer [see comments]. Science. 1993, 260: 812-816.View ArticlePubMedGoogle Scholar
- Haydon AM, Jass JR: Emerging pathways in colorectal-cancer development. Lancet Oncol. 2002, 3: 83-88. 10.1016/S1470-2045(02)00649-6View ArticlePubMedGoogle Scholar
- Gryfe R, Kim H, Hsieh ET, Aronson MD, Holowaty EJ, Bull SB, Redston M, Gallinger S: Tumor microsatellite instability and clinical outcome in young patients with colorectal cancer. N Engl J Med. 2000, 342: 69-77. 10.1056/NEJM200001133420201View ArticlePubMedGoogle Scholar
- Wright CM, Dent OF, Barker M, Newland RC, Chapuis PH, Bokey EL, Young JP, Leggett BA, Jass JR, Macdonald GA: Prognostic significance of extensive microsatellite instability in sporadic clinicopathological stage C colorectal cancer. Br J Surg. 2000, 87: 1197-1202. 10.1046/j.1365-2168.2000.01508.xView ArticlePubMedGoogle Scholar
- Watson P, Lin KM, Rodriguez-Bigas MA, Smyrk T, Lemon S, Shashidharan M, Franklin B, Karr B, Thorson A, Lynch HT: Colorectal carcinoma survival among hereditary nonpolyposis colorectal carcinoma family members [see comments]. Cancer. 1998, 83: 259-266. 10.1002/(SICI)1097-0142(19980715)83:2<259::AID-CNCR9>3.3.CO;2-SView ArticlePubMedGoogle Scholar
- Saeterdal I, Gjertsen MK, Straten P, Eriksen JA, Gaudernack G: A TGF betaRII frameshift-mutation-derived CTL epitope recognised by HLA-A2-restricted CD8+ T cells. Cancer Immunol Immunother. 2001, 50: 469-476. 10.1007/s002620100222View ArticlePubMedGoogle Scholar
- Saeterdal I, Bjorheim J, Lislerud K, Gjertsen MK, Bukholm IK, Olsen OC, Nesland JM, Eriksen JA, Moller M, Lindblom A, Gaudernack G: Frameshift-mutation-derived peptides as tumor-specific antigens in inherited and spontaneous colorectal cancer. Proc Natl Acad Sci U S A. 2001, 98: 13255-13260. 10.1073/pnas.231326898PubMed CentralView ArticlePubMedGoogle Scholar
- Ropponen KM, Eskelinen MJ, Lipponen PK, Alhava E, Kosma VM: Prognostic value of tumour-infiltrating lymphocytes (TILs) in colorectal cancer. J Pathol. 1997, 182: 318-324. 10.1002/(SICI)1096-9896(199707)182:3<318::AID-PATH862>3.3.CO;2-YView ArticlePubMedGoogle Scholar
- Naito Y, Saito K, Shiiba K, Ohuchi A, Saigenji K, Nagura H, Ohtani H: CD8+ T cells infiltrated within cancer cell nests as a prognostic factor in human colorectal cancer. Cancer Res. 1998, 58: 3491-3494.PubMedGoogle Scholar
- Dolcetti R, Viel A, Doglioni C, Russo A, Guidoboni M, Capozzi E, Vecchiato N, Macri E, Fornasarig M, Boiocchi M: High prevalence of activated intraepithelial cytotoxic T lymphocytes and increased neoplastic cell apoptosis in colorectal carcinomas with microsatellite instability. Am J Pathol. 1999, 154: 1805-1813.PubMed CentralView ArticlePubMedGoogle Scholar
- Guidoboni M, Gafa R, Viel A, Doglioni C, Russo A, Santini A, Del Tin L, Macri E, Lanza G, Boiocchi M, Dolcetti R: Microsatellite instability and high content of activated cytotoxic lymphocytes identify colon cancer patients with a favorable prognosis. Am J Pathol. 2001, 159: 297-304.PubMed CentralView ArticlePubMedGoogle Scholar
- Michael-Robinson JM, Biemer-Huttmann A, Purdie DM, Walsh MD, Simms LA, Biden KG, Young JP, Leggett BA, Jass JR, Radford-Smith GL: Tumour infiltrating lymphocytes and apoptosis are independent features in colorectal cancer stratified according to microsatellite instability status. Gut. 2001, 48: 360-366. 10.1136/gut.48.3.360PubMed CentralView ArticlePubMedGoogle Scholar
- Anderson KM, Srivastava PK: Heat, heat shock, heat shock proteins and death: a central link in innate and adaptive immune responses. Immunol Lett. 2000, 74: 35-39. 10.1016/S0165-2478(00)00246-7View ArticlePubMedGoogle Scholar
- Todryk SM, Melcher AA, Dalgleish AG, Vile RG: Heat shock proteins refine the danger theory. Immunology. 2000, 99: 334-337. 10.1046/j.1365-2567.2000.00002.xPubMed CentralView ArticlePubMedGoogle Scholar
- Shibata D, Peinado MA, Ionov Y, Malkhosyan S, Perucho M: Genomic instability in repeated sequences is an early somatic event in colorectal tumorigenesis that persists after transformation. Nat Genet. 1994, 6: 273-281. 10.1038/ng0394-273View ArticlePubMedGoogle Scholar
- Todryk SM, Melcher AA, Hardwick N, Linardakis E, Bateman A, Colombo MP, Stoppacciaro A, Vile RG: Heat Shock Protein 70 Induced During Tumor Cell Killing Induces Th1 Cytokines and Targets Immature Dendritic Cell Precursors to Enhance Antigen Uptake. The Journal of Immunology. 1999, 163: 1398-1408.PubMedGoogle Scholar
- Banchereau J, Steinman RM: Dendritic cells and the control of immunity. Nature. 1998, 392: 245-252. 10.1038/32588View ArticlePubMedGoogle Scholar
- Duval A, Hamelin R: Genetic instability in human mismatch repair deficient cancers. Ann Genet. 2002, 45: 71-75. 10.1016/S0003-3995(02)01115-2View ArticlePubMedGoogle Scholar
- Bocker-Edmonston T, Cuesta KH, Burkholder S, Barusevicius BS, Rose D, Kovatich AJ, Boman B, Fry R, Fishel R, Palazzo J: Colorectal Carcinomas With High Microsatellite Instability:Defining a Distinct immunologic and Molecular Entity With Respect to Prognostic Markers. Hum Pathol. 2000, 31: 1506-1514. 10.1053/hupa.2000.20383View ArticleGoogle Scholar
- Bustin SA, Li SR, Phillips S, Dorudi S: Expression of HLA class II in colorectal cancer: evidence for enhanced immunogenicity of microsatellite-instability-positive tumours. Tumour Biol. 2001, 22: 294-298. 10.1159/000050630View ArticlePubMedGoogle Scholar
- Lovig T, Andersen SN, Thorstensen L, Diep CB, Meling GI, Lothe RA, Rognum TO: Strong HLA-DR expression in microsatellite stable carcinomas of the large bowel is associated with good prognosis. Br J Cancer. 2002, 87: 756-762. 10.1038/sj.bjc.6600507PubMed CentralView ArticlePubMedGoogle Scholar
- Bicknell DC, Kaklamanis L, Hampson R, Bodmer WF, Karran P: Selection for beta 2-microglobulin mutation in mismatch repair-defective colorectal carcinomas. Curr Biol. 1996, 6: 1695-1697. 10.1016/S0960-9822(02)70795-1View ArticlePubMedGoogle Scholar
- Mori Y, Selaru FM, Sato F, Yin J, Simms LA, Xu Y, Olaru A, Deacu E, Wang S, Taylor JM, Young J, Leggett B, Jass JR, Abraham JM, Shibata D, Meltzer SJ: The impact of microsatellite instability on the molecular phenotype of colorectal tumours. Cancer Res. 2003, 63: 4577-4582.PubMedGoogle Scholar
- Bertucci F, Salas S, Eysteries S, Nasser V, Finetti P, Ginestier C, Charafe-Jauffret E, Loriod B, Bachelart L, Montfort J, Victorero G, Viret F, Ollendorff V, Fert V, Giovaninni M, Delpero JR, Nguyen C, Viens P, Monges G, Birnbaum D, Houlgatte R: Gene expression profiling of colon cancer by DNA microarrays and correlation with histoclinical parameters. Oncogene. 2004, 23: 1377-1391. 10.1038/sj.onc.1207262View ArticlePubMedGoogle Scholar
- Dunican DS, McWilliam P, Tighe O, Parle-McDermott A, Croke DT: Gene expression differences between the microsatellite instability (MIN) and chromosomal instability (CIN) phenotypes in colorectal cancer revealed by high-density cDNA array hybridization. Oncogene. 2002, 21: 3253-3257. 10.1038/sj.onc.1205431View ArticlePubMedGoogle Scholar
- Yuan Z, Sotsky Kent T, Weber TK: Differential expression of DOC-1 in microsatellite-unstable human colorectal cancer. Oncogene. 2003, 22: 6304-6310. 10.1038/sj.onc.1206609View ArticlePubMedGoogle Scholar
- Zhang X, Chen Z, Huang H, Gordon JR, Xiang J: DNA microarray analysis of the gene expression profiles of naive versus activated tumour-specific T cells. Life Sci. 2003, 71: 3005-3017. 10.1016/S0024-3205(02)02164-1.View ArticleGoogle Scholar
- Banerjea A, Phillips SM, Dorudi S, Bustin SA: Colorectal cancers with mononucleotide microsatellite instability can be identified using microfabricated chip technology. Anal Biochem. 2003, 322: 130-133. 10.1016/j.ab.2003.07.006View ArticlePubMedGoogle Scholar
This article is published under license to BioMed Central Ltd. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.