Mitochondrial proteome: altered cytochrome c oxidase subunit levels in prostate cancer

Laser capture microdissection was combined with reverse phase protein lysate arrays to quantitatively analyze the ratios of mitochondrial encoded cytochrome c oxidase subunits to nuclear encoded cytochrome c oxidase subunits, and to correlate the ratios with malignant progression in human prostate tissue specimens. Cytochrome c oxidase subunits I-III comprise the catalytic core of the enzyme and are all synthesized from mitochondrial DNA. The remaining subunits (IV-VIII) are synthesized from cellular nuclear DNA. A significant (P < 0.001, 30/30 prostate cases) shift in the relative concentrations of nuclear encoded cytochrome c oxidase subunits IV, Vb, and VIc compared to mitochondrial encoded cytochrome c oxidase subunits I and II was noted during the progression of prostate cancer from normal epithelium through premalignant lesions to invasive carcinoma. Significantly, this shift was discovered to begin even in the premalignant stage. Reverse phase protein lysate array-based observations were corroborated with immunohistochemistry, and extended to a few human carcinomas in addition to prostate. This analysis points to a role for nuclear DNA encoded mitochondrial proteins in carcinogenesis; underscoring their potential as targets for therapy while highlighting the need for full characterization of the mitochondrial proteome.     

On the human body's inductive features: A comment on "Bioelectrical parameters em leader " by A.L. Lafargue et al

The original article to which this Comment refers was published in Bioelectromagnetics 23:450–454 Bioelectromagnetics (2002) 23(5) 450–454     

EspH,a new cytoskeleton-modulating effector of enterohaemorrhagic and enteropathogenic Escherichia coli

Enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) are closely related pathogens. During infection, EPEC and EHEC use a type III secretion system (TTSS) to translocate effector proteins into the infected cells and thereby modify specific host functions. These include transient filopodium formation which is Cdc42-dependent. Filopodia formation is followed by assembly of actin pedestals, the process enhanced by inhibition of Cdc42. We discovered that orf 18 of the enterocyte effacement locus encodes a new effector, which we termed EspH. We show that EspH is translocated efficiently into the infected cells by the TTSS and localizes beneath the EPEC microcolonies. Inactivation of espH resulted in enhanced formation of filopodia and attenuated the pedestals formation. Furthermore, overexpression of EspH resulted in strong repression of filopodium formation and heightened pedestal formation. We also demonstrate that overexpression of EspH by EHEC induces marked elongation of the typically flat pedestals. Similar pedestal elongation was seen upon infection of COS cells overexpressing EspH. EspH transiently expressed by the COS cells was localized to the membrane and disrupted the actin cytoskeletal structure. Our findings indicate that EspH is a modulator of the host actin cytoskeleton structure.     

Immunohistochemical diagnosis of preinvasive germ cell cancer of the testis

The aim of the study was to identify testicular carcinoma in situ (CIS), a precursor of germ cell tumours (GCT), in patients from the high risk groups, using classic and alternative immunohistochemical methods. 70 patients with 46,XY karyotype were examined. Whole gonads or biopsy specimens were fixed in Bouin's fluid. In cases with dysgenetic male pseudohermaphroditism (DMP), gross histopathology revealed sex cord tumour gonadoblastoma in 4 and malignant dysgerminoma in 1 out of 23 patients. In all patients, paraffin sections were treated with antibodies against placental-like alkaline phosphatase (PLAP), a classic immunohistochemical marker of GCT and CIS. CIS was detected immunohistochemically in 10 out of 23 cases with DMP (43.5%), in 1 out of 10 cases with androgen insensitivity syndrome (10%), in 3 out of 18 cases operated previously because of already developed GCT in contralateral testis (16.6%) and in 1 out of 3 patients with cryptorchidism in anamnesis (33.3%). CIS was not found in 16 examined adult infertile men with azoospermia. In addition to PLAP investigation, 12 cases with DMP and 6 cases with GCT were examined using M2A and TRA-1-60 antibodies, the alternative immunohistochemical markers of CIS. While in DMP positive reactions for M2A and TRA-1-60 accompanied PLAP reaction in 1/3 of cases, M2A accompanied PLAP in all cases with GCT. The positive reaction for TRA-1-60 accompanied PLAP and M2A in 1 case with GCT. The results indicate that among different risk groups the highest incidence of CIS occurs in DMP. Screening for CIS is of importance also in cryptorchidism, androgen insensitivity syndrome and in men who underwent gonadectomy because of unilateral GCT. The immunostaining for PLAP seems to be more discriminative procedure. The positive staining of CIS cells with M2A and TRA-1-60 antibodies may be indicative for more advanced neoplastic transformation.     

Tightly clustered 11q23 and 22q11 breakpoints permit PCR-based detection of the recurrent constitutional t(11;22)

Palindromic AT-rich repeats (PATRRs) on chromosomes 11q23 and 22q11 at the constitutional t(11;22) breakpoint are predicted to induce genomic instability, which mediates the translocation. A PCR-based translocation-detection system for the t(11;22) has been developed with PCR primers flanking the PATRRs of both chromosomes, to examine the involvement of the PATRRs in the recurrent rearrangement. Forty unrelated carriers of the t(11;22) balanced translocation, plus two additional, independent cases with the supernumerary-der(22) syndrome, were analyzed to compare their translocation breakpoints. Similar translocation-specific junction fragments were obtained from both derivative chromosomes in all 40 carriers of the t(11;22) balanced translocation and from the der(22) in both of the offspring with unbalanced supernumerary-der(22) syndrome, suggesting that the breakpoints in all cases localize within these PATRRs and that the translocation is generated by a similar mechanism. This PCR strategy provides a convenient technique for rapid diagnosis of the translocation, indicating its utility for prenatal and preimplantation diagnosis in families including carriers of the balanced translocation.     

Protein recovery using two-phase systems

The technology and the main economic aspects of extractive recovery of intracellular enzymes and other biological active proteins are reviewed briefly. It will be seen that the method has high potential and is already used industrially.