Modulation of Intracellular Calcium Levels by Calcium Lactate Affects Colon Cancer Cell Motility through Calcium-Dependent Calpain

Cancer cell motility is a key phenomenon regulating invasion and metastasis. Focal adhesion kinase (FAK) plays a major role in cellular adhesion and metastasis of various cancers. The relationship between dietary supplementation of calcium and colon cancer has been extensively investigated. However, the effect of calcium (Ca²⁺) supplementation on calpain-FAK-motility is not clearly understood. We sought to identify the mechanism of FAK cleavage through Ca²⁺ bound lactate (CaLa), its downstream signaling and role in the motility of human colon cancer cells. We found that treating HCT116 and HT-29 cells with CaLa immediately increased the intracellular Ca²⁺ (iCa²⁺) levels for a prolonged period of time. Ca²⁺ influx induced cleavage of FAK into an N-terminal FAK (FERM domain) in a dose-dependent manner. Phosphorylated FAK (p-FAK) was also cleaved in to its p-N-terminal FAK. CaLa increased colon cancer cells motility. Calpeptin, a calpain inhibitor, reversed the effects of CaLa on FAK and pFAK cleavage in both cancer cell lines. The cleaved FAK translocates into the nucleus and modulates p53 stability through MDM2-associated ubiquitination. CaLa-induced Ca²⁺ influx increased the motility of colon cancer cells was mediated by calpain activity through FAK and pFAK protein destabilization. In conclusion, these results suggest that careful consideration may be given in deciding dietary Ca²⁺ supplementation to patient undergoing treatment for metastatic cancer.     

Simultaneous saccharification and protein enrichment fermentation of sugar beet pulp

Summary A product with 40 % protein content was obtained from sugar beet pulp (1.25–2.0 mm) in 48 h one stage (simultaneous) saccharification/fermentation process under optimized conditions using a specific enzyme mixture andCandida tropicalis strain, also saving about 40 % enzymes in comparison to a 2-stage process.     

Selection of preculture conditions for solid state fermentation of sugar beet pulp

Summary For the protein upgrading of sugar-beet pulp in solid state fermentation byTrichoderma reesei andFusarium oxysporum, serveral conditions were studied to prepare an economical preculture for large scale process. The best performance was shown by a preculture obtained in 24 h from 1.5 % molasses solution at pH 4.5–5.0 with 1.0 % milled beet pulp.     

Interrelation of active oxygen species,membrane damage and altered calcium functions

Incubation of freshly isolated rat liver mitochondria in the presence of oxygen free radical generating hypoxanthine —xanthine oxidase system led to swelling of mitochondria as measured by the change in optical density, which was reversed by the addition of superoxide dismutase. O₂ ^– in the presence of CaCl₂ enhanced the peroxidative decomposition of mitochondrial membrane lipids along with swelling of the organelle. Free radical generation led to enhancement of monoamine oxidase activity while glutathione peroxidase and cytochrome c oxidase were inhibited. Tertbutyl hydroperoxide (t-BHP) caused mitochondrial swelling through oxidative stress. Incorporation of ruthenium red, which is a Ca²⁺ transport blocker, during assay abolished peroxidative membrane damage and swelling. Dithiothreitol (DTT) accorded protection against t-BHP induced mitochondrial swelling. The above in vitro data suggest a possible interrelationship of active oxygen species, membrane damage and calcium dynamics.     

HLA and autoimmunity in North Indian type I (insulin-dependent) diabetic multiplex families

The HLA haplotype segregation and autoantibody spectrum in 7 type I (insulin-dependent) diabetic multiplex families of North Indian origin were determined. Of the total of 17 diabetic sibs, 7 shared both haplotypes and 3 shared one haplotype with the proband. No HLA-non-identical sibs were observed. This distribution of haplotypes was non-random (P approximately equal to 0.005). The mode of inheritance was compatible with an autosomal recessive model, while a dominant model was unlikely. Pancreatic islet-cell antibodies were found in 23.5% of affected sibs, but in no healthy family member. A high incidence of other autoantibodies (parietal-cell and thyroglobulin/thyroid microsomal antibodies) was detected in both the diabetic patients (26.3%), and in healthy first-degree relatives (22.2%). These findings emphasize the role of HLA-linked genes and autoimmunity in the pathogenesis of type I diabetes in North India.     

Extremely high frequencies of alpha-globin gene deletion in Madang and on Kar Kar Island, Papua New Guinea.

Extremely high frequencies of the deletion form of alpha(+)-thalassemia (-alpha/), as studied by the DNA mapping technique, were found in the population of Madang, a coastal province in the north of Papua New Guinea (PNG) and in the population of Kar Kar, an island situated near Madang. Ninety-seven percent of the population tested from Madang and 89% of that from Kar Kar Island were either alpha(+)-thalassemia heterozygotes or homozygotes. By contrast, no examples of the deletion form were detected in the Eastern Highlands of PNG. The haplotype frequencies of alpha(+)-thalassemia (-alpha/) in Madang and Kar Kar Island were found to be 81.33% and 66.67%, respectively. A more detailed analysis of the gene deletion revealed that in both populations 96% were of the 4.2 kilobase (kb) type and 4% were of the 3.7-kb type. Thus, this group is the only example in which the 4.2-kb deletion is predominant over 3.7-kb defect. The presence in high frequencies of alpha(+)-thalassemia in the coastal area of Madang and on the neighboring island, where malaria has long been holoendemic or hyperendemic, and its virtual absence from the nonmalarious highlands of PNG suggest the role of malaria as the selective factor in maintaining alpha(+)-thalassemia. If this selective pressure is still operating, and since alpha(+)-thalassemia has no apparent homozygous disadvantage, the abnormal haplotype (-alpha/) will be in the process of fixation in this population.     

A population genetic study of the Banks and Torres Islands (Vanuatu) and of the Santa Cruz Islands and polynesian outliers (Solomon Islands)

As part of a multidisciplinary survey of populations in the Banks and Torres Islands of Vanuatu and the Southern and Central Districts of the Solomon Islands, nearly 2,400 persons have been tested for ABO blood groups and a number of serum protein and red cell enzyme genetic marker systems. For the ABO system, the populations are characterized in general by high gene O and low gene B frequencies except in two of the Polynesian Outlier Islands, Rennell and Bellona, which have high frequencies of B. Among the serum proteins, several alleles have distributions indicating significant movement of people between islands. These include Albumin ^{New Guinea} and the transferrin alleles Tf, and Tf, and Tf. Similar specific alleles for red cell enzymes also show distributions reflecting interisland population movement as well as contact with persons from outside the southern Pacific region. Examples are ACP in the acid phosphatase system, PGM and PGM, PGM and PGM, PGK⁴ and also HbJ^Tongariki. The data available for 11 polymorphic systems were used to generate genetic distances. Of the four Polynesian Outlier Islands, Anuta is most remote genetically, with Rennell and Bellona also relatively isolated. The fourth Polynesian Outlier, Tikopia, occupies a position genetically close to the Melanesian populations of the Banks and Torres Islands and the southern Solomons. The history of early European contact and voyaging in the Pacific, as well as archaeological and linguistic evidence and local legends, indicate that significant movements of people occurred between islands and provided opportunities for genes to be introduced from Europeans, Africans, and Asians. The genetic marker studies give evidence for genes from all these sources, though at a low level. Despite this admixture, the Polynesian Outlier and Melanesian populations have preserved their own distinctive genetic patterns.     

Purification, crystallization, and X-ray diffraction studies of lactotransferrin from buffalo colostrum.

Lactotransferrin is an iron-binding protein. It has been purified from buffalo colostrum. The purified lactotransferrin has been crystallized in 10% ethanol solution. The crystals are orthorhombic and the space group is P2(1)2(1)2(1) with unit cell dimensions a = 161.70 A, b = 155.75 A, c = 113.48 A. The asymmetric unit contains three molecules of the protein with a solvent content of about 59%. The crystals were stable in the X-ray beam and diffract beyond 3.5 A resolution. The native data have been collected and the structure determination is in progress.