Association of XRCC3 rs1799794 polymorphism with survival of glioblastoma multiforme patients treated with combined radio-chemotherapy.

This study reports the results of a monocentric prospective analysis conducted with the aim of evaluating the impact of XRCC1 rs25487, XRCC3 rs861539, XRCC3 rs1799794, RAD51 rs1801320 and GSTP-1 rs1695 single nucleotide polymorphisms (SNP) on patients with high-grade glioma treated with concomitant radio-chemotherapy. From October 2010 to August 2019, a total of 75 patients aged ≥18 years, with histological diagnosis of high-grade glioma, isocitrate dehydrogenase (IDH) 1/2 wild type and treated with radio-chemotherapy and sequential chemotherapy with temozolomide (TMZ) were prospectively recruited. The local ethic committee approved this study (Comitato Etico di Area Vasta Nord Ovest [CEAVNO]; protocol 3304/2011). After a median follow up of 25 months (range: 7-98 months), median progression-free survival (PFS) and overall survival (OS) were 11 months (CI95%: 8-14 months) and 18 months (CI95%: 15-21 months), respectively. In univariate and multivariate Cox regression analysis, a statistically significant association with PFS and OS was found with XRCC3 rs1799794 SNP. The study suggests that XRCC3 rs1799794 SNP can be associated with different PFS and OS in glioblastoma patients treated with radio-chemotherapy.

Association of Glutathione S-Transferase P-1 (GSTP-1) rs1695 polymorphism with overall survival in glioblastoma patients treated with combined radio-chemotherapy.

Glioblastoma (GBM) is the most frequent malignant primary brain tumor in adults and, despite recent advances, the prognosis for this cancer remains dismal. The aims of this study were to test the influence of XRCC1 rs25487, XRCC3 rs861539, XRCC3 rs1799794, RAD51 rs1801320 and GSTP-1 rs1695 single nucleotide polymorphisms on progression free survival (PFS) and overall survival (OS) in GBM patients treated with radiotherapy (RT) and temozolomide (TMZ). Fifty GBM patients treated with upfront radio-chemotherapy (RT 60 Gy/30 sessions; TMZ 75 mg/m2 during RT and 200 mg/m2 days 1 â†’ 5 every 28 days) were enrolled. Survival curves were calculated using the Kaplan-Meier method, and the log-rank test was used to evaluate differences between curves. A trend to a statistically significant association with PFS in univariate and multivariate COX regression analysis was found with GSTP-1 rs1695 polymorphism (p = 0.087 and p = 0.097 on univariate and multivariate analyses, respectively). Conversely, the same GSTP-1 rs1695 SNP revealed a statistically significant association with OS (p = 0.007 and p = 0.042 on univariate and multivariate analysis, respectively). Our pharmacogenetic prospective study suggests that GSTP-1 rs1695 genotypes can be associated with different OS in GBM patients treated with RT and TMZ.

Homozygous T172T and Heterozygous G135C Variants of Homologous Recombination Repairing Protein RAD51 are Related to Sporadic Breast Cancer Susceptibility.

Breast cancer (BC) is the most common cancer and the second leading cause of death among women worldwide. Only 10% of BC cases have been related to genetic predisposition. Rad51, a homologous recombination (HR) protein plays an important role in HR in meiosis and repairing DNA double-strand breaks. Expression of RAD51 may be a predictive biomarker in certain types of cancers. The exact mechanisms involved in the regulation of RAD51 expression are not fully understood, but certain transcription factors have been suggested to be the tuning mechanism of its expression. In this study, we propose that polymorphisms in the 5'-UTR promoter region of the RAD51 gene are prognostic factors for BC development. Direct sequencing of 106 samples from sporadic BC patients and 54 samples from a control group was performed. FFPE samples were the choice of sample collection, which might be a limitation of our study. Homologous variant T172T alone was found to be significantly associated with BC risk (OR 3.717, 95% CI 2.283-6.052, p < 0.0001). On the other hand, heterozygous G135C did not show any significant relationship with risk of sporadic BC (OR 1.598, 95% CI 0.5638-4.528, p > 0.05). Moreover, both variants; homozygous T172T and heterozygous G135C together; showed a significant relationship with sporadic BC susceptibility.

c-KIT receptor expression is strictly associated with the biological behaviour of thyroid nodules.

BACKGROUND: A large amount of information has been collected on the molecular tumorigenesis of thyroid cancer. A low expression of c-KIT gene has been reported during the transformation of normal thyroid epithelium to papillary carcinoma suggesting a possible role of the gene in the differentiation of thyroid tissue rather than in the proliferation. The initial presentation of thyroid carcinoma is through a nodule and the best way nowadays to evaluate it is by fine-needle aspiration (FNA). However many thyroid FNAs are not definitively benign or malignant, yielding an indeterminate or suspicious diagnosis which ranges from 10 to 25% of FNAs. BRAF mutational analysis is commonly used to assess the malignancy of thyroid nodules but unfortunately it still leaves indeterminate diagnoses. The development of molecular initial diagnostic tests for evaluating a thyroid nodule is needed in order to define optimal surgical approach for patients with uncertain diagnosis pre- and intra-operatively. METHODS: In this study we extracted RNA from 82 FNA smears, 46 malignant and 36 benign at the histology, in order to evaluate by quantitative Real Time PCR the expression levels of c-KIT gene. RESULTS: We have found a highly preferential decrease rather than increase in transcript of c-KIT in malignant thyroid lesions compared to the benign ones. To explore the diagnostic utility of c-KIT expression in thyroid nodules, its expression values were divided in four arbitrarily defined classes, with class I characterized by the complete silencing of the gene. Class I and IV represented the two most informative groups, with 100% of the samples found malignant or benign respectively. The molecular analysis was proven by ROC (receiver operating characteristic) analysis to be highly specific and sensitive improving the cytological diagnostic accuracy of 15%. CONCLUSION: We propose the use of BRAF test (after uncertain cytological diagnosis) to assess the malignancy of thyroid nodules at first, then the use of the c-KIT expression to ultimately assess the diagnosis of the nodules that otherwise would remain suspicious. The c-KIT expression-based classification is highly accurate and may provide a tool to overcome the difficulties in today's preoperative diagnosis of thyroid suspicious malignancies.

A mouse mammary tumor virus env-like exogenous sequence is strictly related to progression of human sporadic breast carcinoma.

A viral etiology of human breast cancer (HBC) has been postulated for decades since the identification of mouse mammary tumor virus (MMTV). The detection of MMTV env-like exogenous sequences (MMTVels) in 30% to 40% of invasive HBCs increased attention to this hypothesis. Looking for MMTVels during cancer progression may contribute to a better understanding of their role in HBC. Herein, we analyzed HBC preinvasive lesions for the presence of MMTVels. Samples were obtained by laser microdissection of FFPE tissues: 20 usual-type ductal hyperplasias, 22 atypical ductal hyperplasias (ADHs), 49 ductal carcinomas in situ (DCISs), 20 infiltrating ductal carcinomas (IDCs), and 26 normal epithelial cells collateral to a DCIS or an IDC. Controls included reductive mammoplastic tissue, thyroid and colon carcinoma, and blood samples from healthy donors. MMTVels were detected by fluorescence-nested PCR. DNA samples from the tissues of nine patients were analyzed by real-time quantitative PCR, revealing a different viral load correlated with stage of progression. Furthermore, as never previously described, the presence of MMTVels was investigated by chromogenic in situ hybridization. MMTVels were found in 19% of normal epithelial cells collateral to a DCIS or an IDC, 27% of ADHs, 82% of DCISs, and 35% of IDCs. No MMTVels were found in the control samples. Quantitative PCR and chromogenic in situ hybridization confirmed these results. These data could contribute to our understanding of the role of MMTVels in HBC.

KLF4 is a novel candidate tumor suppressor gene in pancreatic ductal carcinoma.

Ductal pancreatic carcinoma (DPC) is a deadly disease with an incidence of 9 cases in 100,000 people per year and a mortality rate close to 100%. Allelic losses in the long arm of chromosome 9 are commonly encountered in many human malignancies but no data are yet available about DPC. We screened 40 laser-microdissected DPC samples and 6 pre-invasive lesions for 9 microsatellite mapping markers of region 9q21.3 through 9q34.2. A small overlapping region of deletion, spanning 8 million base pairs, was identified between D9S127 and D9S105. Two genes, RSG3 and KLF4, mapped to 9q31.1 through 9q32, were further investigated. A highly significant association was found between KLF4 gene expression levels and genomic status. Similarly, absence of immunohistochemical expression of KLF4 protein was found in 86.8% cases of DPC (33/38). Overexpression of KLF4 in a human pancreatic carcinoma cell line induced a significant decrease in the proliferation associated with up-regulation of p21 and the down-regulation of cyclin D1. In conclusion, we identified a novel oncosuppressor region located at the 9q 31.1-3 locus that is lost in DPC at high frequency. Loss of KLF4 expression is closely related to the genomic loss, and its restoration inhibits cancer cell proliferation, suggesting a key suppressor role in pancreatic tumorigenesis.

A molecular computational model improves the preoperative diagnosis of thyroid nodules.

BACKGROUND: Thyroid nodules with indeterminate cytological features on fine needle aspiration (FNA) cytology have a 20% risk of thyroid cancer. The aim of the current study was to determine the diagnostic utility of an 8-gene assay to distinguish benign from malignant thyroid neoplasm. METHODS: The mRNA expression level of 9 genes (KIT, SYNGR2, C21orf4, Hs.296031, DDI2, CDH1, LSM7, TC1, NATH) was analysed by quantitative PCR (q-PCR) in 93 FNA cytological samples. To evaluate the diagnostic utility of all the genes analysed, we assessed the area under the curve (AUC) for each gene individually and in combination. BRAF exon 15 status was determined by pyrosequencing. An 8-gene computational model (Neural Network Bayesian Classifier) was built and a multiple-variable analysis was then performed to assess the correlation between the markers. RESULTS: The AUC for each significant marker ranged between 0.625 and 0.900, thus all the significant markers, alone and in combination, can be used to distinguish between malignant and benign FNA samples. The classifier made up of KIT, CDH1, LSM7, C21orf4, DDI2, TC1, Hs.296031 and BRAF had a predictive power of 88.8%. It proved to be useful for risk stratification of the most critical cytological group of the indeterminate lesions for which there is the greatest need of accurate diagnostic markers. CONCLUSION: The genetic classification obtained with this model is highly accurate at differentiating malignant from benign thyroid lesions and might be a useful adjunct in the preoperative management of patients with thyroid nodules.

Acral Dedifferentiated Chondrosarcoma: Report of a Case Arising in the Proximal Phalanx of the Fourth Finger.

Dedifferentiated chondrosarcoma is a well-recognized entity, but its occurrence in the distal extremities is exceedingly rare. We present the case of a 49-year-old woman who experienced local recurrence of an "enchondroma" of the proximal phalanx of the fourth finger of the left hand, which had been initially treated with intralesional curettage at another hospital 4 years before, and 1 year before for a local recurrence. The imaging findings indicated an aggressive behavior, and an incisional biopsy showed a highly cellular proliferation of spindle and pleomorphic elements without evidence of matrix production intermixed with few fragments of a well-differentiated cartilaginous neoplasm with bland cellular atypia, focal nuclear hyperchromatism, and binucleation. An isocitrate dehydrogenase 2 R172S mutation was detected. The final diagnosis was dedifferentiated chondrosarcoma. Despite amputation of the fourth finger, the patient developed lung metastases and further local relapse. Recurrent cartilaginous tumors of the extremities should not be underestimated and should be followed in view of the possible acquisition of aggressive clinical behavior.

Mouse mammary tumor virus (MMTV) - like exogenous sequences are associated with sporadic but not hereditary human breast carcinoma.

The inheritance of mutated suppressor genes, such as BRCA1 and BRCA2, is acknowledged as an etiological factor in hereditary breast carcinoma (HBC). Two different molecular mechanisms are possible; the Knudson's "two hits" or the gene haploinsufficiency. Etiology of sporadic breast carcinoma (SBC) is not known, although data support the possible role of the betaretrovirus Mouse Mammary Tumor Virus (MMTV). This study analyzes the presence of MMTV exogenous sequences in two representative groups of HBC and SBC, excluding any contamination by murine and retroviral material and endogenous betaretroviruses. The 30.3% of 56 SBC contained MMTV sequences, against the 4.2% of 47 HBC (p < 0.001). Cases positive for viral sequences showed the presence of p14, signal peptide of the MMTV envelope precursor. This result was expected based on the fact that HBCs, having a specific genetic etiology, do not need the action of a carcinogenetic viral agent. Moreover, the striking results obtained by comparing two groups of vastly different tumors represent an additional element of quality control: the distinction between HBC and SBC is so well-defined that results cannot be ascribed to mere coincidence. This paper strengthens the hypothesis for a viral etiology for human sporadic breast carcinoma.

Molecular characterization of low grade and high grade bladder cancer.

BACKGROUND: Bladder cancer (BC) is the 9th most common cancer diagnosis worldwide. Low grade (LG) represents 70% of all BCs, characterized by recurrence and rare ability (10-15%) to progress to high grade (HG) and invade. The remaining 30% is high grade (HG), fast invasive BC, which is resistant to therapy. Identifying biomarkers for predicting those tumors able to progress is a key goal for patient outcome improvement. This study focuses on the most promising prognostic markers. MATERIALS AND METHODS: TP53 and FGFR3 mutational status, Survivin, CK19, CK20, E-cadherin and CD44 gene expression analysis were performed on 66 BCs. RESULTS: Survivin was found associated to tumor grade (p<0.05). Moreover, Survivin correlated with CD44 in TP53 wild type (p = 0.0242) and FGFR3 wild type (p = 0.0036) tumors. In particular the Survivin-CD44 correlation was associated to HG FGFR3 wild type BCs (p = 0.0045). Unsupervised hierarchical clustering based on gene expression data identified four distinct molecular groups reflecting the patient histology (p = 0.038). CONCLUSION: We suggest Survivin, both as a biomarker associated to G3 BCs but negatively related to TP53 mutational status, and as a potential novel therapeutic target.

Common cancer biomarkers.

There is an increasing interest in complementing conventional histopathologic evaluation with molecular tools that could increase the sensitivity and specificity of cancer staging for diagnostic and prognostic purposes. This study strove to identify cancer-specific markers for the molecular detection of a broad range of cancer types. We used 373 archival samples inclusive of normal tissues of various lineages and benign or malignant tumors (predominantly colon, melanoma, ovarian, and esophageal cancers). All samples were processed identically and cohybridized with an identical reference RNA source to a custom-made cDNA array platform. The database was split into training (n = 201) and comparable prediction (n = 172) sets. Leave-one-out cross-validation and gene pairing analysis identified putative cancer biomarkers overexpressed by malignant lesions independent of tissue of derivation. In particular, seven gene pairs were identified with high predictive power (87%) in segregating malignant from benign lesions. Receiver operator characteristic curves based on the same genes could segregate malignant from benign tissues with 94% accuracy. The relevance of this study rests on the identification of a restricted number of biomarkers ubiquitously expressed by cancers of distinct histology. This has not been done before. These biomarkers could be used broadly to increase the sensitivity and accuracy of cancer staging and early detection of locoregional or systemic recurrence. Their selective expression by cancerous compared with paired normal tissues suggests an association with the oncogenic process resulting in stable expression during disease progression when the presently used differentiation markers are unreliable.

Functional Interaction Between BRCA1 and DNA Repair in Yeast May Uncover a Role of RAD50, RAD51, MRE11A, and MSH6 Somatic Variants in Cancer Development.

In this study, we determined if BRCA1 partners involved in DNA double-strand break (DSB) and mismatch repair (MMR) may contribute to breast and ovarian cancer development. Taking advantage the functional conservation of DNA repair pathways between yeast and human, we expressed several BRCA1 missense variants in DNA repair yeast mutants to identify functional interaction between BRCA1 and DNA repair in BRCA1-induced genome instability. The pathogenic p.C61G, pA1708E, p.M775R, and p.I1766S, and the neutral pS1512I BRCA1 variants increased intra-chromosomal recombination in the DNA-repair proficient strain RSY6. In the mre11, rad50, rad51, and msh6 deletion strains, the BRCA1 variants p.C61G, pA1708E, p.M775R, p.I1766S, and pS1215I did not increase intra-chromosomal recombination suggesting that a functional DNA repair pathway is necessary for BRCA1 variants to determine genome instability. The pathogenic p.C61G and p.I1766S and the neutral p.N132K, p.Y179C, and p.N550H variants induced a significant increase of reversion in the msh2Δ strain; the neutral p.Y179C and the pathogenic p.I1766S variant induced gene reversion also, in the msh6Δ strain. These results imply a functional interaction between MMR and BRCA1 in modulating genome instability. We also performed a somatic mutational screening of MSH6, RAD50, MRE11A, and RAD51 genes in tumor samples from 34 patients and identified eight pathogenic or predicted pathogenic rare missense variants: four in MSH6, one in RAD50, one in MRE11A, and two in RAD51. Although we found no correlation between BRCA1 status and these somatic DNA repair variants, this study suggests that somatic missense variants in DNA repair genes may contribute to breast and ovarian tumor development.

Cancer astrocytes have a more conserved molecular status in long recurrence free survival (RFS) IDH1 wild-type glioblastoma patients: new emerging cancer players.

Glioblastoma is a devastating disease that despite all the information gathered so far, its optimal management remains elusive due to the absence of validated targets from clinical studies. A better clarification of the molecular mechanisms is needed. In this study, having access to IDH1 wild-type glioblastoma of patients with exceptionally long recurrence free survival (RFS), we decided to compare their mutational and gene expression profile to groups of IDH1 wild-type glioblastoma of patients with shorter RFS, by using NGS technology. The exome analysis revealed that Long-RFS tumors have a lower mutational rate compared to the other groups. A total of 158 genes were found differentially expressed among the groups, 112 of which distinguished the two RFS extreme groups. Overall, the exome data suggests that shorter RFS tumors could be, chronologically, in a more advanced state in the muli-step tumor process of sequential accumulation of mutations. New players in this kind of cancer emerge from the analysis, confirmed at the RNA/DNA level, identifying, therefore, possible oncodrivers or tumor suppressor genes.

Polymorphisms and mutations in GSTP1, RAD51, XRCC1 and XRCC3 genes in breast cancer patients.

BACKGROUND: Genotoxic factors, including ionizing radiation and oxidative stress, are associated with genomic instability and development of breast cancer (BC). The homologous recombination DNA repair (HRR) pathway, base excision repair (BER) mechanism, and antioxidative enzymes are required as defense mechanisms against these DNA damaging agents. GSTP1, XRCC1, XRCC3 and RAD51 proteins are essential components of antioxidation, BER and HRR of DNA, respectively. Deficiencies in BER, HRR and antioxidation pathways are involved in the progression of cancer. METHODS: Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue and blood samples of BC patients of an Italian population. Genomic DNA was also extracted from blood specimens of a control group. DNA sequencing was performed for six single-nucleotide polymorphisms (SNPs) in the GSTP1, RAD51, XRCC1 and XRCC3 genes in BC patients and the control group. RESULTS: Two variants in the 5'-UTR of the XRCC3 (rs1799794 A/G) and RAD51 (rs1801321) genes showed a significant association with susceptibility to BC (OR = 4.125; 95% CI 1.057-16.102; p = 0.03 and OR = 2.04; 95% CI 0.4925-8.449; p = 0.007, respectively). Additionally, we reported 2 mutations in intron 7 of the XRCC3 gene, CTdel (rs543072564) and A/G (rs369703243). CONCLUSIONS: Our results underscored the existence of an association between XRCC3-5'-UTR-A/G (rs1799794) and RAD51-5'-UTR G172T (rs1801321) genotypes and BC risk in an Italian population. The presence of mutations in the intronic region of the XRCC3 gene highlights the importance of more sequence screening of DNA repair genes for possible genetic penetrance in BC.

Investigating molecular alterations to profile short- and long-term recurrence-free survival in patients with primary glioblastoma.

Glioblastoma (GB) is the most aggressive type of primary brain tumor. Despite the progress in recent years regarding the diagnosis and treatment of GB, the recurrence rate remains high, due to the infiltrative and dispersive nature of the tumor, which typically results in poor patient prognosis. In the present study, 19 formalin-fixed, paraffin-embedded GB samples were selected from patients with GB tumors. The samples were classified into a short or long recurrence-free survival (RFS) group, based on the time of first recurrence of the disease in the patients. The 19 samples were molecularly characterized for mutations in the isocitrate dehydrogenase 1 (IDH1) gene, amplification of the epidermal growth factor receptor (EGFR) gene, presence of the EGFR variant III, and methylation of the promoter region of the O6-methylguanine-DNA methyltransferase (MGMT) gene. Then, the expression of 84 genes involved in cell-cell and cell-matrix interactions, and that of 84 microRNAs (miRNAs) associated with brain cancer, was profiled. In addition, a copy number variation analysis of 23 genes reported to undergo frequent genomic alterations in human glioma was also performed. Differences in the expression levels of a number of genes were detected across the short and long RFS groups. Among these genes, 5 in particular were selected, and a 5-genes combination approach was developed, which was able to differentiate between patients with short and long RFS outcome. The high levels of sensitivity and precision displayed by this 5-genes combination approach, which were confirmed with a cross-validation method, provide a strong foundation for further validation of the involvement of the aforementioned genes in GB in a larger patient population. In conclusion, the present study has demonstrated how the expression pattern of miRNAs and mRNAs in patients with GB defines a particular molecular hallmark that may increase or reduce the aggressive behavior of GB tumors, thus influencing the survival rates of patients with GB, their response to therapy and their tendency to suffer a relapse.

Human saliva as route of inter-human infection for mouse mammary tumor virus.

Etiology of human breast cancer is unknown, whereas the Mouse Mammary Tumor Virus (MMTV) is recognized as the etiologic agent of mouse mammary carcinoma. Moreover, this experimental model contributed substantially to our understanding of many biological aspects of the human disease. Several data strongly suggest a causative role of MMTV in humans, such as the presence of viral sequences in a high percentage of infiltrating breast carcinoma and in its preinvasive lesions, the production of viral particles in primary cultures of breast cancer, the ability of the virus to infect cells in culture. This paper demonstrates that MMTV is present in human saliva and salivary glands. MMTV presence was investigated by fluorescent PCR, RT-PCR, FISH, immunohistochemistry, and whole transcriptome analysis. Saliva was obtained from newborns, children, adults, and breast cancer patients. The saliva of newborns is MMTV-free, whereas MMTV is present in saliva of children (26.66%), healthy adults (10.60%), and breast cancer patients (57.14% as DNA and 33.9% as RNA). MMTV is also present in 8.10% of salivary glands. RNA-seq analysis performed on saliva of a breast cancer patient demonstrates a high expression of MMTV RNA in comparison to negative controls. The possibility of a contamination by murine DNA was excluded by murine mtDNA and IAP LTR PCR. These findings confirm the presence of MMTV in humans, strongly suggest saliva as route in inter-human infection, and support the hypothesis of a viral origin for human breast carcinoma.

Melanoma-restricted genes.

Human metastatic cutaneous melanoma has gained a well deserved reputation for its immune responsiveness. The reason(s) remain(s) unknown. We attempted previously to characterize several variables that may affect the relationship between tumor and host immune cells but, taken one at the time, none yielded a convincing explanation. With explorative purposes, high-throughput technology was applied here to portray transcriptional characteristics unique to metastatic cutaneous melanoma that may or may not be relevant to its immunogenic potential. Several functional signatures could be identified descriptive of immune or other biological functions. In addition, the transcriptional profile of metastatic melanoma was compared with that of primary renal cell cancers (RCC) identifying several genes co-coordinately expressed by the two tumor types. Since RCC is another immune responsive tumor, commonalities between RCC and melanoma may help untangle the enigma of their potential immune responsiveness. This purely descriptive study provides, therefore, a map for the investigation of metastatic melanoma in future clinical trials and at the same time may invite consideration of novel therapeutic targets.

Vaccination with T cell-defined antigens.

Tumour immunology encompasses a broad array of biological phenomena including interactions between neoplastic cells and the innate and adaptive immune response. Among immune cells, T cells have taken the centre stage because they can be easily demonstrated to specifically recognise autologous cancer cells. As most tumour-associated antigens are intracellular proteins, T cells appear to be the most suitable tool for cancer-specific attack, as antibodies do not cross the cell membrane and the innate immune response lacks the same level of specificity. Finally, the relative ease in which T cells can be educated through antigen-specific immunisation to recognise cancer cells has elevated them to an even higher stature. In this review, it will be argued that T cells represent a unique anticancer agent, characterised by absolute specificity. Although other therapeutic modalities (antibody-based) have been effectively implemented, a comparison of T cell-based approaches with other modalities goes beyond the purposes of this review and will not be included in the discussion. However, it is obvious that the role of the T cell is limited and other components of the immune response (effector mononuclear phagocytes, natural killer cells, cytokines, chemokines, soluble factors), genetic background and tumour heterogeneity are likely to be necessary for the completion of cancer rejection.

Overview of melanoma vaccines and promising approaches.

It is difficult to envision anything better than melanoma vaccines to exemplify the effectiveness of modern biotechnology in developing biologically rational therapeutics. Melanoma vaccines can reproducibly induce cytotoxic T lymphocyte (CTL) responses better than any other anticancer therapy. Anticancer vaccines have been labeled by some as ineffective for the simple reason that they only rarely lead to cancer regression. This oxymoron stems from the naïve expectation that CTLs are all that is needed to reject cancer. Little is known about requirements for CTL localization and effector function within the tumor microenvironment. In the future, more attention should be given to events downstream of immunization (afferent arm of immune response) to identify combination therapies likely to facilitate localization and activation of CTL at the receiving end (efferent arm).