Soluble natural sweetener from date palm (Phoenix dactylifera L.) extract using colloidal gas aphrons generated with a food-grade non-ionic surfactant.

Date palm (Phoenix dactylifera L.) is the most commonly cultivated fruit tree in the Middle East and North Africa. Date fruits are an excellent source of nutrition due to their high sugar content and high levels of phenols, minerals, and antioxidants. This work aimed to prepare a soluble natural sweetener from date fruit extract using colloidal gas aprons (CGAs) generated with a food-grade non-ionic surfactant (Tween 20). Various process parameters, such as the flow rate of the CGAs, the volume of the feed, the temperature of the CGAs, and the feed solution, were varied to obtain the optimal parameters. In the foam phase, the maximum soluble sugar enrichment of 92% was obtained at a flow rate of 50 mL/min of CGA and a solution temperature of 23 °C. The formation of intermolecular hydrogen bonding between the glucose molecules and the surfactant Tween 20 was confirmed by molecular modeling studies. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05907-9.

Prospective assessment of allelic losses at 4p14-16 in colorectal cancer: two mutational patterns and a locus associated with poorer survival.

Previous studies have shown that allelic losses in a locus mapping to the chromosomal region 4p14-16 are indicative of poor prognosis in colorectal cancer. To further characterize the region involved and to confirm earlier observations, we have analyzed losses of heterozygosity (LOH) in nine microsatellite markers spanning this region in a prospective series of 181 colorectal carcinomas. The extent and the nature of the allelic imbalance were also ascertained by comparative genomic hybridization analysis of selected cases. The minimum common deleted region was confined to marker D4S2397 (LOH in 35% of the informative cases). Surrounding markers displayed LOH in 13-25% of informative cases and (other than the D4S2397 marker itself) showed a higher rate of allelic imbalances in association with mutations in the p53 tumor suppressor gene. Tumors with lymph node invasion also displayed increased rates of LOH in most markers. Regarding patient outcome, LOH solely at the D4S2397 locus was indicative of a shorter disease-free survival (P = 0.027). In consequence, two patterns of allelic loss are defined within the 4p14-16 region: (a) gross losses associated with tumor progression and probably attributable to the genomic instability related to the inactivation of the p53 tumor suppressor gene; and (b) specific losses limited to the D4S2397 locus (within an estimated fragment of 2 Mb) and associated with increased tumor aggressiveness. The presence of one or more putative tumor suppressor genes in this region is postulated.

Overall deregulation in gene expression as a novel indicator of tumor aggressiveness in colorectal cancer.

Malignant transformation of the cell is accompanied and characterized by disruption of genetic material and aberrant expression of multiple genes. Systematic analysis of differential gene expression in human tumor samples may provide an estimate of the degree of genetic and epigenetic deregulation in neoplastic cells. We have assessed, by means of a RNA differential display technique, the overall gene expression deregulation in a prospectively collected series of 68 human colorectal carcinomas. An index of differential expression has been calculated for each case. A similar proportion of the displayed sequences (23%) was under- and over-represented in the tumor in respect of the normal tissue. An increased variation in the expression profile was observed in advanced Dukes' stages (P < 0.02) and correlated with lymph node invasion (P < 0.05). Furthermore, a diminished overall survival was associated to increased rates of deregulation (Log-rank, P < 0.02) and especially down-regulation (P < 0.001). When Cox multivariate analysis was performed in front of Dukes' stage, both indexes of differential expression were independent indicators of a worse outcome (P = 0.05 and P < 0.01 respectively). We conclude that estimation of the fraction of differentially displayed tags by RNA fingerprinting may have relevant applications in the prognostic assessment of colorectal cancer.

p53 and K-ras gene mutations correlate with tumor aggressiveness but are not of routine prognostic value in colorectal cancer.

PURPOSE: p53 gene and K-ras mutations are among the most common genetic alterations present in colorectal cancer. The prognostic utility of such mutations remains controversial. The purpose of this study was to prospectively evaluate the prognostic significance of p53 and K-ras gene mutations in colorectal cancer. PATIENTS AND METHODS: One hundred forty patients were analyzed. Tumors belonging to the microsatellite mutator phenotype were excluded (n = 8). Mutations at the K-ras and p53 genes were detected and characterized by restriction fragment length polymorphism, single-strand conformation polymorphism, and sequencing, as appropriate. RESULTS: p53 mutations were detected in 66 (50%) and K-ras mutations were detected in 54 (41%) of the 132 patients. In 26 cases (20%), ras and p53 mutations coexisted; in 38 cases (29%), neither mutation was found. Multivariate analysis of the whole population analyzed (n = 132) showed that survival was strongly correlated with the presence of p53 mutations alone or in combination with K-ras mutations (P = .002; log-rank test). When only patients undergoing a radical resection were considered (R0; n = 101), p53 mutations were no longer of prognostic significance. CONCLUSION: p53 mutations alone or in combination with K-ras mutations are correlated with a worse outcome. However, the routine use of these mutations as prognostic markers in the clinical setting is not recommended.

Tracking recurrent quantitative genomic alterations in colorectal cancer: allelic losses in chromosome 4 correlate with tumor aggressiveness.

Allelic imbalances are common events in cancer cells. Quantitative alterations in specific chromosomal loci have been linked to activation (gain) or inactivation (loss) of genes with a proven impact on tumor cell biology. The aim of this study was to detect new chromosomal regions recurrently altered in colorectal tumorigenesis and with a potential effect on patient's outcome. We have analyzed a series of human colorectal tumor biopsy specimens by using the DNA fingerprinting technique arbitrarily primed PCR. This approach provided information on 95 different loci randomly selected and distributed through out the cell's genome. Eight sequences displayed recurrent alterations associated with diminished patient survival. Four of them (showing allelic losses) were located in chromosome 4, one sequence in chromosome 2, and one sequence in chromosome 17. The chromosomal origin of the two remaining sequences could not be determined. Fine mapping of chromosome 4 bands suggested that there are at least two regions in chromosome 4 (4p14-16 and 4q21-28) susceptible to containing tumor suppressor genes the loss of which may affect tumor aggressiveness.

Analysis of differential gene expression in human colorectal tumor tissues by RNA arbitrarily primed-PCR: a technical assessment.

RNA arbitrarily primed (RAP)-PCR is a powerful tool for studying differential gene expression in cancer cells. Systematic analysis of human tumor samples may provide a list of markers with potential application to the diagnosis, prognostic assessment, and treatment of the disease. Nevertheless, because of characteristics inherent to the samples and technique, artifactual results are likely. We have assessed the effects of several factors on RAP-PCR performance to determine the sensitivity and reproducibility of the technique, as well as the accuracy of its results, under different conditions in human cell lines and in a series of 129 paired human normal colonic mucosa-colorectal carcinoma samples. Our results show that RAP-PCR provides reliable fingerprints in a relatively wide spectrum of circumstances, including variations in RNA concentration and contamination by DNA. Densitometric analysis indicated that relative band-intensity variations more than 20% were reproducible in 95% of the cases. Serial analysis of paired normal-tumor cases yielded a number of bands that were recurrently either underexpressed or overexpressed in tumor relative to normal mucosa. These differentially expressed bands are prime targets of research because they represent candidate tumor-specific up- or down-regulated genes with a relevant role in carcinogenesis.

PRAD-1/cyclin D1 gene amplification correlates with messenger RNA overexpression and tumor progression in human laryngeal carcinomas.

PRAD-1 is a putative oncogene localized on chromosome 11q13 which encodes cyclin D1, a novel cyclin involved in cell cycle regulation. Amplification of this gene has recently been reported in several human tumors including breast and head and neck carcinomas. In this study we have analyzed the presence of PRAD-1/cyclin D1 gene amplification and mRNA overexpression in a series of 46 matched normal mucosas and squamous cell carcinomas of the larynx. PRAD-1/cyclin D1 was found to be amplified 2- to 12-fold in 17 carcinomas (37%). DNA amplification correlated with advanced local invasion (P = 0.0015), presence of lymph node metastases (P = 0.0078), and stage IV of the tumors (P = 0.0021). mRNA overexpression was found in 15 of the 43 (35%) cases examined and it was also significantly associated with advanced local invasion (P = 0.0025) and stage IV carcinomas (P = 0.0032). A significant association was observed between gene amplification and mRNA overexpression (P < 0.0001) with only 3 discordant cases (2 amplifications with no overexpression and 1 overexpressed carcinoma with no gene amplification). Furthermore, the degree of DNA amplification correlated with the levels of mRNA expression (r = 0.6; P = 0.024). These findings suggest that the PRAD-1/cyclin D1 gene may be an important target of 11q13 amplifications in laryngeal carcinomas and the activation of this gene may be involved in the progression of these tumors. Its association with advanced-stage tumors indicates that PRAD-1/cyclin D1 gene amplification and overexpression may be of prognostic significance.