Phase transitions in hydrophobe/phospholipid mixtures: hints at connections between pheromones and anaesthetic activity

The phase behavior of a mixture of a typical insect pheromone (olean) and a phospholipid (DOPC)/water dispersion is extensively explored through SAXS, NMR and DSC experiments. The results mimic those obtained with anaesthetics in phospholipid/water systems. They also mimic the behavior and microstructure of ternary mixtures of a membrane mimetic, bilayer-forming double chained surfactants, oils and water. Taken together with recent models for conduction of the nervous impulse, all hint at lipid involvement and the underlying unity in mechanisms of pheromone, anaesthetic and hydrophobic drugs, where a local phase change in the lipid membrane architecture may be at least partly involved in the transmission of the signal

Mouse mammary tumour virus-like env nucleotide and p14 signal peptide are present in feline mammary carcinomas, but not in neoplastic or dysplastic canine mammary lesions

Mouse mammary tumour virus-like (MMTV-like) is suspected to be involved in human breast cancer and it has been hypothesized that companion animals might have a role in viral transmission. The aim of our study was to investigate the presence of MMTV-like nucleotide sequences and viral protein in a larger number of feline (FMCs) and canine mammary carcinomas (CMCs) by nested PCR and immunohistochemistry. Results showed that the presence of MMTV-like env sequence in FMCs was 7% (6/86), while all the CMCs and canine dysplastic lesions scored negative. All PCR-positive FMCs scored positive for the MMTV p14 signal peptide of the envelope precursor protein of the virus. In contrast, all PCR-negative FMCs and canine mammary lesions were also negative for immunohistochemistry analysis. Canine and feline normal mammary gland tissues scored negative for both PCR and MMTV-p14 protein. Multiple nucleotide alignment of MMTV-like env gene sequences isolated from cat showed 97% and 99% similarity with HMTV and MMTV, respectively, while the others two presented some polimorphisms. Particularly the sequences of one of these two tumors showed a polymorphism (c.7575 A> G), that causes a previously unreported amino acid substitution (Thr > Ala). In conclusion, the results of our study showed the presence of MMTV-like sequences and viral protein in some FMCs. Further studies are needed to understand whether this virus does play a role in the development of FMCs, if MMTV-like is an exogenous virus as these data suggest and, in such a case, how and from whom this virus was acquired

PRESENZA DI SEQUENZE ED ANTIGENE DI MOUSE MAMMARY TUMOR VIRUS (MMTV)- LIKE IN NEOPLASIE MAMMARIE FELINE E CANINE

RIASSUNTO Tra le possibili cause del carcinoma mammario della donna è stato ipotizzato il ruolo di un retrovirus simile al virus del Tumore Mammario Murino (MMTV-like), per questo si ritiene che gli animali da compagnia potrebbero aver importanza nella trasmissione di questo virus. Lo scopo della tesi è stato quello di indagare sulla presenza di sequenze nucleotidiche e proteine di MMTV-like in carcinomi mammari di gatto (FMCs), lesioni mammarie neoplastiche e displastiche canine e tessuti mammari sani delle due specie. Le indagini sono state condotte mediante nested-PCR e immunoistochimica. I risultati hanno mostrato la presenza di sequenza env di MMTV-like nel 7% (6/86) dei FMCs, mentre tutte le lesioni displasiche e neoplastiche canine sono risultate negative, come i tessuti sani di controllo. Tutti i FMCs a PCR+ sono risultati positivi per il peptide di segnale MMTV p14 della proteina precursore del virus. Al contrario, tutte le lesioni PCR-negative, le lesioni mammarie canine ed i tessuti di controllo sono risultate negative alle indagini di immunoistochimica. L'allineamento delle sequenze amplificate dai FMCs del gene env del virus MMTV-like hanno mostrato per quattro ceppi amplificati un’omologia tra il 97% ed il 99% rispetto al ceppo di referenza di MMTV, mentre gli altri due hanno mostrato un polimorfismo che in uno dei due ceppi è risultato in grado di indurre una sostituzione aminoacidica (Thr>Ala) fino ad oggi sconosciuta. Per questo la sequenza identificata sarà depositata in GenBank come MMTV-like felino. In conclusione, i risultati del nostro studio hanno mostrato la presenza di sequenze e proteine virali di un retrovirus MMTV-like in alcuni FMCs. Ulteriori studi sono necessari per capire se questo virus possa svolgere un ruolo nello sviluppo dei FMCs e se, comportandosi come virus esogeno, come e quando le gatte possono acquisire l’infezione. Parole chiave : virus MMTV-like; tumori mammari canini; tumori mammary feline; immunoistochimica; nested-PCR.

Multiple nucleotide alignment of the MMTV-like env gene sequences.

<p>A) The env sequences from two feline mammary tumors (indicated by their respective number) were aligned with NIH 3T3 (positive control for MMTV), mouse mammary tumor virus from HeJ mice, and HMTV (accession numbers AF228551.1 and AF243039, respectively). B) DNA sequencing, confirming the MMTV sequences. Surprisingly, one of them (Cat 87768) showed a polymorphism (c.7575 A> G), that cause aminoacyl substitution (Thr> Ala).</p

Correlation between MMTV-like p14 expression and pathological findings of feline mammary carcinomas investigated.

<p>Correlation between MMTV-like p14 expression and pathological findings of feline mammary carcinomas investigated.</p

Fluorescent-PCR to detect MMTV-like sequence in feline mammary tumors.

<p>Fragment analysis show the blue peaks that represent the size of fragment (191bp) detected by capillary electrophoresis method.</p

Pathological features of the 53 canine and 86 feline mammary carcinomas examined.

<p>Pathological features of the 53 canine and 86 feline mammary carcinomas examined.</p

Immunohistochemical expression of p14 MMTV env protein in feline mammary carcinomas.

<p>(A) FMC # 84471. Tubulopapillary FMC PCR-negative and negative for MMTV p14 expression (Immunoperoxidase-DAB, Bar = 100 μm) (B) FMC # 84589. Tubulopapillary FMC PCR-positive, a weak cytoplasmic immunostaining was detected in some neoplastic epitrhelial cells (Immunoperoxidase-DAB, Bar = 100 μm). (C) FMC # 80613. Tubolopapillary FMC, some neoplastic epithelial cells show distict cytoplasmic MMTV p14 labelling (Immunoperoxidase-DAB, Bar = 100 μm). (D) FMC # 86367. Solid FM, a large number of carcinoma cells show cytoplasmic p14 staining, Scattered inflammatory cells associated with neoplastic proliferation resulted MMTV p14-positive (Immunoperoxidase-DAB, Bar = 100 μm).</p

Determination of phylogentic relationships of Env sequences identified in different hosts.

<p>A neighbor-joining phylogenetic tree from nucleotide sequences of env of MMTV viruses. The tree was rooted to HERV-K. The robustness of individual nodes of the tree was determined by using bootstrap analyses of 1,00 replicates.</p