Carlos Gamallo

Aldehyde dehydrogenase enzymes are a family of intracellular enzymes that participate in cellular detoxification, differentiation and drug resistance through the oxidation of cellular aldehydes. The isoform 1 (ALDH1) has been proved useful for the identification of cancer stem cells. The ALDH1 cytoplasmatic expression has been associated with poor prognostis in several tumours, such as non-small cell lung cancer. The role of the ALDH1 nuclear expression remains unknown.

Background HIF-1alpha plays a key role in the development and progression of cancer. Its polymorphic variants C1772T and G1790A have been associated with greater susceptibility to cancer and increased tumor progression. Methods We determined the distribution of these polymorphisms among 121 patients with glottic cancer and 154 healthy volunteers by PCR–RFLP. We also analyzed the relationship between the presence of these polymorphisms and various clinicopathologic variables. Results Advanced tumors (T3–T4) were associated with the TT variant (p = 0.036), which was present in 75 % of T4 tumors (p = 0.008). Among patients with nodal metastasis (N+), 41.7 and 22 % were carrying the TT and GA variants, respectively, compared with 9.4 and 2 % of the patients with no metastasis (N0), (p = 0.006 and p = 0.032). Conclusions The presence of the TT and GA variants were associated with lymph node metastasis, while the presence of the TT variant can be associated with larger tumor size.

Thymidylate synthase and hypoxia inducible factor-1α play a central role in the control of tumor progression. In the present study, we investigated the effect of three DNA polymorphisms within the thymidylate synthase gene and two within hypoxia inducible factor-1α on the prognosis of pancreatic cancer. A retrospective study was performed in 59 patients diagnosed with invasive ductal adenocarcinoma of the pancreas and 159 healthy volunteers. The studied DNA polymorphisms were a variable tandem repeat of 28 bp (rs45445694), a G/C single nucleotide polymorphism (rs34743033), and a deletion of 6 bp (ins1494del 6bp; rs34489327) within the thymidylate synthase gene and C1772T and G1790A single nucleotide polymorphisms within hypoxia inducible factor-1α (rs11549465 and rs11549467, respectively) . Variable tandem repeats were determined by specific polymerase chain reaction, whereas thymidylate synthase single nucleotide polymorphism G/C, ins1494del 6pb, and hypoxia inducible factor-1α polymorphisms were identified by polymerase chain reaction and RFLP. Thymidylate synthase and hypoxia inducible factor-1α genotype distributions in patients and healthy volunteers were determined. The impact of the polymorphisms on clinico-pathological variables, including survival, was also studied. The frequency of carriers of the variant del6bp allele was significantly higher among patients (70.0% vs 51.0% of healthy donors, P = 0.02); 42% of male patients were homozygous 2R/2R vs 13.6% of females (P = 0.03), but differences regarding gender were not observed among healthy volunteers. Concerning hypoxia inducible factor-1α C1772T and G1790A single nucleotide polymorphisms, the rates of variant T/T and A/A homozygous genotypes were significantly elevated among patients (18.6% vs 5.3%, P = 0.001, and 5.1% vs none, P = 0.021 respectively). In our study, the variant del14946bp allele within the thymidylate synthase gene, and TT and AA genotypes of C1772T and G1790A hypoxia inducible factor-1α single nucleotide polymorphisms were associated with the development of pancreatic cancer. The 2R/2R genotype of variable tandem repeat thymidylate synthase polymorphism might be a risk factor for pancreatic cancer in males.

The presence of intratumoral lymphatic vessels (ILVs) and the expression of vascular endothelial growth factor-C (VEGF-C) in tumour cells have been studied as markers of lymphangiogenesis in order to evaluate their role in metastatic dissemination in laryngopharyngeal squamous cell carcinoma. A retrospective study was performed in 76 patients of N0 laryngopharyngeal carcinoma. with variable tumour size (T1-T4), histological grade, and location (supraglottic, glottic and hypopharyngeal). The presence of ILVs, as revealed by the expression of PA2.26 antigen and VEGF-C expression, were determined by immunohistochemistry (IHC). Low-grade and high-grade lymphangiogenesis were defined by qualitative and quantitative criteria. Multivariate analysis revealed low-grade ILV and VEGF-C expression to be associated respectively with 30.3- and 16.2-fold higher probabilities of cervical lymph node relapse (P = 0.005 and P = 0.032) and with 16.2- and 8.44-fold shorter disease-free survival (P = 0.009 and P = 0.045). Low-grade ILV and VEGF-C expression are independent predictive factors of cervical lymph node relapse and shortening of time to relapse in N0 laryngopharyngeal carcinoma.

BACKGROUND: The loss of cadherin expression has been shown to correlate to the invasion and metastasis of many types of carcinomas. The purpose of the current study was to evaluate whether the impaired expression of E‐cadherin (E‐cad) and P‐cadherin (P‐cad) correlated with the clinical evolution and prognosis of oral squamous cell carcinoma (OSCC).METHODS: The authors used immunohistochemical methods to analyze the expression pattern of E‐cad and P‐cad in healthy oral mucosa, in oral carcinoma in situ (CIS), and in surgical samples of 50 patients with the early stages (Stages I–II) of OSCC.RESULTS: E‐cad showed weak expression in the basal layer of the healthy oral mucosa and reduced expression in patients with oral CIS. P‐cad expression was conserved on the basal and suprabasal layers of the healthy mucosa and, also, in the CIS. In the group of patients with OSCC, univariate analysis demonstrated that reduced expression of E‐cad or P‐cad correlated significantly with locoregional disease recurrence in the follow‐up (P= 0.03 andP= 0.01, respectively). However, only the reduction in the expression of P‐cad emerged as an independent prognostic marker in the multivariate analysis (P= 0.04, hazard ratio = 8.06).CONCLUSIONS: These findings suggested that a decrease in E‐cad and/or P‐cad expression may contribute to the invasive potential of early OSCC. According to the current data, P‐cad expression may be a potential independent prognostic factor in patients with OSCC. Cancer 2005. © 2005 American Cancer Society.

High intratumoral expression of thymidylate synthase (TS) has been reported as a factor of poor prognosis in patients with advanced colorectal cancer (CRC), but such association is unclear in some studies. Also, TS has been stated as a typical cytosolic enzyme, but nuclear location has been occasionally reported, and data on the clinical meaning of TS intracellular location are scarce. A retrospective study was performed in paraffin-embedded sections of primary tumor from 77 CRC patients treated with surgical resection and adjuvant 5-FU-based chemotherapy. TS levels and expression patterns were determined by immunohistochemistry (IHQ) using TS-106 antibody. Qualitative and quantitative variables were compared respectively by chi2 and Kruskal-Wallis tests; overall survival (OS) and disease-free survival (DFS) were analyzed with the Kaplan-Meier method and compared using the log-rank and Wilcoxon tests. TS was cytoplasmic in 27.1% of positive tumors and both, nuclear and cytoplasmic in 72.9%; specimens from seven patients (9.1%) lacked TS expression. TS levels were high in 21.6% of tumors with nuclear expression and low in 5.6%, whereas 68.4% of cytoplasmic ones showed low immunostaining intensity (p=0.02); cytoplasmic pattern was also associated to longer OS (p<0.009) and DFS (p=0.003). In patients with nuclear expression, low TS expression was associated to shorter OS (p<0.003) and DFS (p<0.04). These results indicate that, in our study, TS immunostaining patterns were related with OS and DFS, the best prognostic corresponding to cytoplasmic one, and, within the subset of patients with nuclear expression, low TS levels were associated to worse clinical outcome.

BACKGROUND: Clinicopathologic data demonstrated that the lymphatic system is the main route for solid tumor metastasis. However, the effect of intratumoral lymphangiogenesis (IL) on prognosis in oral carcinoma is still unknown because, until recently, no reliable markers for lymphatic endothelium were available. The current study analyzed the lymphatic vessels in tumor tissue specimens of patients with primary oral carcinoma using the new marker, PA2.26.METHODS: The authors investigated IL in surgical tissue samples of 61 patients with early‐stage (Stages I–II) oral carcinoma. The tissue specimens were stained for PA2.26 and the correlation between IL and relevant parameters was analyzed by the Pearson chi‐square test. In a univariate analysis using the Kaplan–Meier method, IL was analyzed against survival and disease‐free period. Statistical significance of differences between distributions was studied by the log‐rank test. Clinicopathologic parameters, including IL, were entered in a multivariate analysis to determine independent prognostic significance.RESULTS: Thirty‐three patients had IL. In the follow‐up, a strong association was found between IL and locoregional recurrence (30.3 % of the patients with IL and 7.1% of the patients without IL). The presence of IL did not correlate significantly with the pT classification, primary location, or tumor differentiation. IL was found to have no influence on overall survival in univariate analysis, but there was significant association between IL and disease‐free survival (P = 0.03). Multivariate analysis revealed IL to be the sole independent factor influencing disease‐free interval (P = 0.02).CONCLUSIONS: These results suggested that IL is associated with locoregional disease recurrence in early‐stage oral carcinoma. The presence of IL was a useful discriminator in predicting the outcome of patients with absence of lymph node metastasis. Cancer 2004. © 2003 American Cancer Society.

In the present study we explored the effect of three polymorphisms of the TS gene on overall and progression- free survival of colorectal cancer (CRC) patients subjected to 5FU chemotherapy. A 28 bp variable number of tandem repeats (VNTR), a G/C single nucleotide polymorphism (SNP), and a deletion of 6 bp at position 1494 were studied. The possible combined effect of these DNA polymorphisms on the clinical outcome of patients was also evaluated. A retrospective study was carried out on paraffin-embedded sections from 113 patients diagnosed of advanced CRC. TS genotyping methods were polymerase chain reaction (PCR) for VNTR and PCR, followed by restriction length fragment polymorphism (PCR-RFLP) for SNP and ins/del 6 bp. To study the combined effect of TS polymorphisms, four categories were defined accordingly to the level of expression attributed to SNP and ins/del 6 bp genotypes: C&allele 6−, C&6+/6+, G&allele6− and G&6+/6+. VNTR and ins/del 6 bp genotypes varied with tumour anatomical site: 2R/2R genotype was rare in left-sided tumours (7.0% vs. 26.3% of right-sided and 24.1% of rectal cancers; P<0.01), where the variant allele 6− was very frequent (69.0%). Instead, most patients with right-sided tumours were wild-type homozygous 6+/6+ (63.9%) (P<0.01). Heterozygous 6+/6− genotype was more frequent among tumours classified as C (50.0%) and D (76.5%) Dukes stages (P=0.05). None of the studied polymorphisms alone affected overall or progression-free survival (PFS). C&6+/6+ and G&6+/6+ combined genotypes were respectively associated to the best and worst PFS (P=0.03 when compared with each other), while combinations carrying the allele 6− determined an intermediate evolution that might be indicative of a variable response to chemotherapy. The rate of Dukes B stage tumours was unexpectedly high (59.1%) among patients with the unfavourable G&6+/6+ combination. In our study the combination of high TS expression genotypes G&6+/6+ identifies a group of high risk within CRC patients treated with 5FU.