Levodopa-carbidopa intestinal gel infusion (LCIG) in Parkinson disease with genetic mutations

BACKGROUND

Levodopa-carbidopa intestinal gel infusion (LCIG) is a therapeutic option for advanced Parkinson disease (PD) patients with troublesome motor complications, unresponsive to conventional oral treatment. There is some evidence to suggest that the genetic background may influence the clinical presentation and rate of progression of PD. Whether the genetic background influences the outcome of device-assisted therapies is currently debated. Some studies have investigated the effectiveness of deep brain stimulation (DBS) in PD patients with different genetic background, while evidence is lacking regarding LCIG.

METHODS

A cohort of LCIG patients underwent genetic testing. The motor and neuropsychological outcomes of LCIG were retrospectively analyzed.

RESULTS

Fifty-six patients were analyzed, nine of them (15%) had at least one mutation/variant in a PD-associated gene: five GBA1, two SNCA, one LRRK2, one PRKN; 13 (23%) carried the BDNF Val66Met polymorphism. The mean duration of follow-up was 4.9 ± 2.6 years. There were no significant differences in motor or neuropsychological outcomes between patients with and without these gene mutations/variants. No cognitive worsening was observed at follow-up among GBA-PD patients, and they responded well to LCIG in terms of motor symptoms.

CONCLUSIONS

Overall, we observed a significant benefit in terms of motor complications in our cohort, including patients carrying genetic mutations/variants. Due to the small sample and limited number of patients carrying genetic mutations/variants, no definitive conclusions can be drawn yet on the genotype impact on LCIG outcome. A careful selection of patients, regardless of the genetic background, is pivotal for an optimal outcome of LCIG.

Molecular metastases markers in head and neck squamous cell carcinoma: review of the literature

It is now widely accepted that the presence of lymph node metastases is a negative prognostic factor in head and neck squamous cell carcinoma. It follows that the ability to determine the presence of micro-metastases or the metastatic potential of a tumour at an early stage would condition the therapeutic strategy and evolution of this type of tumour. Prediction of the metastatic potential of head and neck squamous cell carcinoma is still, today, entrusted to clinical and histological evaluation of the tumour. However, the high percentage of relapse in this tumour shows the inadequacy of these parameters in predicting metastatic potential. Furthermore, progress made over the last ten years in understanding the molecular mechanisms involved in the process of neoplastic tumour progression has led to the identification of molecules that can be used as potential prognostic markers of head and neck squamous cell carcinoma. There are many molecules involved in the process of forming metastases. This process represents the final stage of a multistep model, in which alterations occur to genes that are important for growth, proliferation and migration, to which are added variations in the expression of molecules involved in the process of homeostasis of the extra-cellular matrix, of angiogenesis and lymphangiogenesis, favouring tumour invasion and the formation of metastases. This review of the literature shows that the tumour invasion process is associated with numerous molecular alterations that might be used as potential prognostic molecular markers. However, none of these alterations is univocally associated with the metastasization used in clinical practice. Further studies on larger series and on a larger scale, such as genome studies, and preclinical studies on markers used as targets in specific therapies, will provide a valuable contribution to their use in clinical practice in the short term.

Aberrant activation of c-kit protects colon carcinoma cells against apoptosis and enhances their invasive potential

Multiple genetic aberrations contribute to the development of biologically aggressive, clinically malignant colorectal carcinomas (CRCs). Some of these have been linked to inappropriate signaling through the tyrosine kinase moieties of growth factor receptors. We have described previously (G. Bellone et al., J. Cell. Physiol., 172: 1-11, 1997) that human CRCs overexpress both the receptor tyrosine kinase c-kit and its ligand, stem cell factor (SCF), relative to normal mucosa cells, thus establishing an autocrine c-kit-mediated loop. In addition, we noted that exogenous SCF contributes to anchorage-independent growth of HT-29 colon carcinoma cells in semisolid medium. Here, we investigated possible roles of the c-kit/SCF autocrine/paracrine system in survival and invasive capacity of DLD-1 colon carcinoma cells. We report that SCF was required for migration and invasion of DLD-1 cells through reconstituted basement membranes (Matrigel) and up-regulated gelatinase (matrix metalloproteinase-9) activity in DLD-1 cells. Furthermore, we describe that SCF supported survival of DLD-1 cells in growth factor-deprived conditions. These results suggest multiple roles of c-kit activation in support of the malignant phenotype of DLD-1 cells related to growth, survival, migration, and invasive potential.

Staging of head and neck squamous cell carcinoma using the MET oncogene product as marker of tumor cells in lymph node metastases

In head and neck squamous cell carcinomas (HNSCC), metastasis to cervical lymph nodes is a major determinant of patient outcome. To detect metastases, we used the MET oncogene as marker, which encodes the receptor for hepatocyte growth factor/scatter factor, mediating epithelial cell motility and invasiveness. The MET gene is expressed in epithelia and over-expressed in carcinomas of specific histotypes, but not in lymphatic tissue. A total of 151 lymph nodes from 20 squamous cell carcinomas were studied with both in-depth histology and end-point and real-time quantitative RT-PCR. MET-encoded sequences were found in 61 of 151 nodes (40%), of which 24 (16%) were found metastatic by in-depth histopathology. Parallel routine histopathologic analysis of 654 lymph nodes from the same cases identified 36 metastases (5%). Real-time quantitative RT-PCR was used to measure MET gene-specific mRNA in normal tissues, primary tumors and lymphatic metastases and showed a 2-8-fold increased expression in tumor cells which metastasize. RT-PCR for 3 cytokeratins expressed in HNSCC (K4, K10 and K13) proved to be less sensitive in detecting occult lymphatic metastases. Western blot analysis demonstrated the presence of the full-size MET receptor in primary tumors and lymph node metastases; immunohistochemistry showed receptor localization in tumor cells. Altogether, these data demonstrate that the MET gene product is a valuable marker with which to detect occult tumor cells in lymph nodes, thanks to its high expression in metastatic cells. After RT-PCR analysis we were able to attribute a more advanced stage to 10 out of 20 HNSCC cases, including 5 cases classified as tumor-free after routine histopathology.

Impact of polymorphisms in xeno(endo)biotic metabolism on pattern and frequency of p53 mutations in bladder cancer

We have analyzed the tumor biopsies of 45 patients with bladder cancer for p53 mutations by direct sequencing. In addition to N-acetyltransferase-2 (NAT2) and GSTM1 allelisms, which were examined previously, we have analyzed the genetic polymorphisms of GSTT1, GSTP1, COMT, NQO1, TS-SULT and MPO in buffy coat DNA using PCR-based methods. All subjects were interviewed through a questionnaire on smoking, dietary habits and other risk factors. No specific pattern was evident for p53 mutations. Eight out of ten mutations occurred in grade 3 tumors. All p53 mutations occurred in subjects with the COMT mutated allele (p=0.03). The prevalence of cases with p53 mutations was 3.5-fold higher in subjects with wild type than in those with variant GSTP1 alleles (p=0.03). The other polymorphisms investigated were not associated with p53 mutations.

Somatic mutations of the MET oncogene are selected during metastatic spread of human HNSC carcinomas

A metastatic cancer develops by accumulation of mutations in genes that control growth, survival and spreading. The latter genes have not yet been identified. In lymph node metastases of head and neck squamous cell carcinomas (HNSCC), we found mutations in the MET oncogene, which encodes the tyrosine kinase receptor for Scatter Factor, a cytokine that stimulates epithelial cell motility and invasiveness during embryogenesis and tissue remodeling. We identified two somatic mutations: the Y1230C, known as a MET germline mutation which predisposes to hereditary renal cell carcinoma, and the Y1235D that is novel and changes a critical tyrosine, known to regulate MET kinase activity. The mutated MET receptors are constitutively active and confer an invasive phenotype to transfected cells. Interestingly, cells carrying the MET mutations are selected during metastatic spread: transcripts of the mutant alleles are highly represented in metastases, but barely detectable in primary tumors. These data indicate that cells expressing mutant MET undergo clonal expansion during HNSCC progression and suggest that MET might be one of the long sought oncogenes controlling progression of primary cancers to metastasis.

White blood cell DNA adducts, smoking, and NAT2 and GSTM1 genotypes in bladder cancer: a case-control study

We conducted a case-control study on 114 bladder cancer patients and 46 hospital controls. DNA adducts were measured in WBCs by 32P postlabeling and showed no association with smoking habits and the glutathione-S-transferase M1 genotype. A strong association between adduct levels and the N-acetyltransferase (NAT2) genotype was found (P = 0.0002). The NAT2 genotype was associated in a nonstatistically significant way to the case-control status (odds ratio, 1.6; 95% confidence interval, 0.8-3.2). In a logistic regression model, the log of DNA adduct levels was associated in a highly significant way to the risk of bladder cancer (regression coefficient, 0.75; P = 0.0006), independently of smoking habits. Using the median of DNA adducts (RAL, 0.3) as a cutoff point, the odds ratio for the risk of bladder cancer was 4.1 (age-adjusted; 95% confidence interval, 1.9-9.0). Our study suggests that sources other than tobacco smoke contribute to the formation of aromatic DNA adducts in WBCs. The role of WBC-DNA adducts in predicting bladder cancer is still to be clarified.

4-Aminobiphenyl-DNA adducts and p53 mutations in bladder cancer

Epidemiologic studies have suggested that smokers of air-cured tobacco (rich in arylamines) are at higher risk of bladder cancer than smokers of flue-cured tobacco. The risk has been shown to be modulated by the N-acetyltransferase genotype. We analyzed the biopsies of 45 patients with bladder cancer. p53 mutations were sought by direct sequencing, and 4-aminobiphenyl-DNA adducts were measured by negative ion gas chromatography-mass spectrometry. 4-Aminobiphenyl-DNA adducts were higher in smokers of air-cured tobacco and in current smokers, but no relationship with the number of cigarettes smoked was found. Adducts were higher in more advanced histologic grades of tumors. No pattern was evident for p53 mutations. Seven of 9 mutations occurred in grade 3 tumors. No association was found between 4-ABP adducts and GSTM1 or NAT2 genetic polymorphisms.

Tobacco smoke, recurrences, and p53/bcl-2 expression in bladder cancer

Overexpression of p53 is considered to be predictive of mutations of the p53 gene. Exposure-specific mutations of the p53 gene have been described for cancers at different sites. An association between p53 mutation/overexpression and smoking has been described in early stage bladder cancer, but results were conflicting. We have conducted a study on 131 bladder cancer cases, considering p53 expression and smoking habits in an area where the use of air-cured tobacco, rich in carcinogenic arylamines, is common. The study suggests that the use of air-cured tobacco induces p53 overexpression (possibly via mutation) in early stage-low grade bladder cancer, more frequently than flue-cured tobacco (odds ratios = 3.4, 95% confidence intervals 0.9-13 in stage 1; odds ratios = 24, 95% confidence intervals 1.1-519 in stage 1, grade 1). However, all the excess associated with air-cured tobacco was concentrated in recurrences. When available, the biopsies of recurrent cases with early-stage disease were re-examined and all showed p53 expression at first diagnosis (with 10-50% of cells positive) (n = 5). It is hypothesized that exposure to tobacco-related chemicals increases the risk of recurrences via p53 overexpression/mutation. Expression of the bcl-2 gene was detected in only 2 out of 13 p53-positive smokers.

Internal migration, coffee drinking, and nonfatal myocardial infarction in Italy

We conducted a hospital-based case-control study of 153 patients who had been recently diagnosed with myocardial infarction; there were 157 hospital controls. All subjects were 35-70-y-old males who lived in the province of Torino (northern Italy). These individuals were nonsmokers or had quit smoking for at least 6 mo. A protective role of migration from southern Italy was found (age-adjusted odds ratio for northern versus southern origin = 1.82, 95% confidence interval = 1.0, 3.3). Although fat consumption differed greatly between those born in northern Italy and those in southern Italy (i.e., the former used mainly butter and the latter used mainly olive oil during their early lives), it did not explain the migration effect. A family history of myocardial infarction increased the risk of a myocardial infarction (odds ratio = 2.4, 95% confidence interval = 1.1, 4.9). Moderate coffee consumption also increased the risk and was not explained by the known coronary risk factors. Relative risks were up to 4 among both nonsmokers and exsmokers who drank more than 4 cups of coffee each day. We controlled for coffee drinking and found that the association with southern origin appeared strengthened.

Exposure to aromatic amines and ras and c-erbB-2 overexpression in bladder cancer

We have analyzed the bladder biopsies of six bladder cancer patients exposed to high levels of 2-naphthylamine and benzidine, 11 unexposed bladder cancer patients, six subjects with benign conditions of the bladder, and 16 healthy subjects. Immunohistochemical analysis of the p21 and p185 protein products, for overexpression of ras and c-erbB-2 oncogenes, was performed. Overexpression of ras was found in four of six exposed cancer patients, 3 of 11 unexposed cancer patients, zero of six benign disease patients, and zero of 16 healthy subjects. The odds ratio for ras overexpression, comparing exposed with unexposed cases, was 5.3 (90% confidence interval 0.6 to 64). Overexpression of c-erB-2 was apparently not associated with occupational exposure.

DNA adducts in urothelial cells: relationship with biomarkers of exposure to arylamines and polycyclic aromatic hydrocarbons from tobacco smoke

Markers of exposure to polycyclic aromatic hydrocarbons (urinary 1-hydroxypyrene-glucuronide) and aromatic amines (4-aminobiphenyl-hemoglobin adducts), as well as urinary mutagenicity, were measured in 47 healthy smokers and 50 nonsmokers. DNA adducts were determined by P32-postlabeling in the exfoliated bladder cells of 39 healthy subjects. Both 1-hydroxypyrene-glucuronide (1-OHPG) and 4-aminobiphenyl adducts (4-ABP-Hb) were associated with smoking habits, but only 4-ABP-Hb adducts were associated with consumption of black, air-cured tobacco. The levels of 2 DNA adducts (numbers 2 and 4) in urothelial cells were clearly associated with 4-ABP-Hb adducts, in all subjects and in smokers. Levels of one of these DNA adducts (number 2) were also associated with 1-hydroxypyrene-glucuronide in urines, but in smokers the association was not statistically significant. Overall, these observations constitute further evidence of a role of arylamines in tobacco-induced bladder cancer.

Molecular epidemiology of bladder cancer

In order to ascertain the role of arylamines in the induction of bladder cancer in smokers, and to assess the contribution of the metabolic phenotype to cancer risk, studies of molecular epidemiology have been conducted. A number of investigations have reported that "slow" acetylators are at higher risk of bladder cancer, especially subgroups occupationally exposed to arylamines. We present the results of studies that investigated markers of both internal dose (hemoglobin adducts, urinary mutagenicity), and genetically determined susceptibility (metabolic polymorphism) among smokers. Levels of ABP-hemoglobin adducts were elevated in smokers of black (air-cured) tobacco compared to smokers of blond tobacco, and "slow" acetylators showed higher levels than "fast" acetylators. Further, a combination of slow acetylator and fast oxidizer phenotype was associated with the highest level of ABP-hemoglobin adduct. Thus the determination of both phenotypes may allow to better predict the risk of bladder cancer than using the "slow" acetylator phenotype alone. Further investigations in this field will consider the occurrence of mutational spectra (hotspots) in relevant genes (e.g.p53 or p16) to ascertain whether tobacco-related carcinogens induce specific mutations.