The incidence of colorectal cancer (CRC) has increased worldwide, and early diagnosis is crucial to reduce mortality rates. Therefore, new noninvasive biomarkers for CRC are required. Recent studies have revealed an imbalance in the oral and gut microbiomes of patients with CRC, as well as impaired gut vascular barrier function. In the present study, the microbiomes of saliva, crevicular fluid, feces, and non‐neoplastic and tumor intestinal tissue samples of 93 CRC patients and 30 healthy individuals without digestive disorders (non‐CRC) were analyzed by 16S rRNA metabarcoding procedures. The data revealed that Parvimonas, Fusobacterium, and Bacteroides fragilis were significantly over‐represented in stool samples of CRC patients, whereas Faecalibacterium and Blautia were significantly over‐abundant in the non‐CRC group. Moreover, the tumor samples were enriched in well‐known periodontal anaerobes, including Fusobacterium, Parvimonas, Peptostreptococcus, Porphyromonas, and Prevotella. Co‐occurrence patterns of these oral microorganisms were observed in the subgingival pocket and in the tumor tissues of CRC patients, where they also correlated with other gut microbes, such as Hungatella. This study provides new evidence that oral pathobionts, normally located in subgingival pockets, can migrate to the colon and probably aggregate with aerobic bacteria, forming synergistic consortia. Furthermore, we suggest that the group composed of Fusobacterium, Parvimonas, Bacteroides, and Faecalibacterium could be used to design an excellent noninvasive fecal test for the early diagnosis of CRC. The combination of these four genera would significantly improve the reliability of a discriminatory test with respect to others that use a single species as a unique CRC biomarker.

The aim of the present study was to identify the signaling mechanism(s) responsible for the modulation of growth hormone secretagogue receptor type 1a (GHSR1a)-associated Akt activity. Ghrelin leads to the activation of Akt through the interplay of distinct signaling mechanisms: an early G(i/o) protein-dependent pathway and a late pathway mediated by beta-arrestins. We found that the Src homology 2-containing protein tyrosine phosphatase (SHP-1) was an essential molecule in both G(i/o) protein-dependent and beta-arrestin-mediated pathways. More specifically, the role of SHP-1 in the G(i/o) protein-dependent pathway was demonstrated by the fact that the overexpression of a catalytically defective SHP-1 augments tyrosine phosphorylation of the PI3K regulatory subunit p85, leading to an increase in the phosphorylation of cSrc and phosphoinositide-dependent protein kinase 1, and finally activating Akt. The presence of SHP-1 in the beta-arrestin-scaffolded complex and its attenuating effect on the cSrc and Akt activities verified that SHP-1 regulates not only the G(i/o) protein-dependent pathway but also the beta-arrestin-mediated pathway. Assays performed in preadipocyte and adipocyte 3T3-L1 cells showed SHP-1 expression. According to our results in HEK-GHSR1a cells, ghrelin stimulated SHP-1 phosphorylation in 3T3-L1 cells. The increase in ghrelin-induced Akt activity was enhanced by small interfering RNA of SHP-1 in preadipocyte 3T3-L1 cells. These results were reproduced in white adipose tissue obtained from mice, in which SHP-1 exhibited higher expression in omental than in subcutaneous tissue. Furthermore, this pattern of expression was inverted in mice fed a high-fat diet, suggesting a role for SHP-1 in controlling ghrelin sensitivity in adipose tissue. Indeed, SHP-1 deficiency was associated with augmented ghrelin-evoked Akt phosphorylation in omental tissue, as well as decreased phosphorylation under overexpression of SHP-1 in subcutaneous tissue. These findings showed a novel role for SHP-1 in the regulation of Akt activity through the modulation of the ghrelin/GHSR1a system signaling.

Oral and intestinal samples from a cohort of 93 colorectal cancer (CRC) patients and 30 healthy controls (non‐CRC) were collected for microbiome analysis. Saliva (28 non‐CRC and 94 CRC), feces (30 non‐CRC and 97 CRC), subgingival fluid (20 CRC), and tumor tissue samples (20 CRC) were used for 16S metabarcoding and/or RNA sequencing (RNAseq) approaches. A differential analysis of the abundance, performed with the ANCOM‐BC package, adjusting the P‐values by the Holm‐Bonferroni method, revealed that Parvimonas was significantly over‐represented in feces from CRC patients (P‐value < 0.001) compared to healthy controls. A total of 11 Parvimonas micra isolates were obtained from the oral cavity and adenocarcinoma of CRC patients. Genome analysis identified a pair of isolates from the same patient that shared 99.2% identity, demonstrating that P. micra can translocate from the subgingival cavity to the gut. The data suggest that P. micra could migrate in a synergistic consortium with other periodontal bacteria. Metatranscriptomics confirmed that oral bacteria were more active in tumor than in non‐neoplastic tissues. We suggest that P. micra could be considered as a CRC biomarker detected in non‐invasive samples such as feces.

The role of the obestatin/GPR39 system in human gastric adenocarcinomas

The quest for therapeutic applications of obestatin involves, as a first step, the determination of its 3D solution structure and the relationship between this structure and the biological activity of obestatin. On this basis, we have employed a combination of circular dichroism (CD), nuclear magnetic resonance (NMR) spectroscopy, and modeling techniques to determine the solution structure of human obestatin (1). Other analogues, including human non-amidated obestatin (2) and the fragment peptides (6–23)-obestatin (3), (11–23)-obestatin (4), and (16–23)-obestatin (5) have also been scrutinized. These studies have been performed in a micellar environment to mimic the cell membrane (sodium dodecyl sulfate, SDS). Furthermore, structural-activity relationship studies have been performed by assessing the in vitro proliferative capabilities of these peptides in the human retinal pigmented epithelial cell line ARPE-19 (ERK1/2 and Akt phosphorylation, Ki67 expression, and cellular proliferation). Our findings emphasize the importance of both the primary structure (composition and size) and particular segments of the obestatin molecule that posses significant α-helical characteristics. Additionally, details of a species-specific role for obestatin have also been hypothesized by comparing human and mouse obestatins (1 and 6, respectively) at both the structural and bioactivity levels.

The use of one-step nucleic acid amplification (OSNA) allows for lymph node (LN) metastasis to be detected rapidly and accurately. We conducted a prospective single-centre clinical trial to evaluate OSNA assay in detecting LN metastasis of lung cancer. A total of 705 LNs from 160 patients with clinical stage IA to IVA lung cancer were included in this study. The LNs were divided and submitted to routine histological diagnosis and OSNA assay and the results were compared. We also examined keratin 19 expression of different histological types lung primary tumours. When the cut-off value was set to 250 copies/µl, the concordance rate between the two methods was 96.17% and the sensitivity 97.14%. Discordant results were observed in 27 LNs of 21 patients. Most of these discordant results were molecular micrometastasis expressing a very low number of copies with negative histology. Most thoracic tumours were positive for keratin 19. Our data show that the OSNA assay might be a useful and sensitive method to diagnose LN metastasis in lung cancer and could be applied to intraoperative decision-making in personalised lung cancer surgery based on LN status and a more accurate staging of patients.