BackgroundMicrobial dysbiosis and microbiome-induced inflammation have emerged as important factors in oral squamous cell carcinoma (OSCC) tumorigenesis during the last two decades. However, the “rare biosphere” of the oral microbiome, including fungi, has been sparsely investigated. This study aimed to characterize the salivary mycobiome in a prospective Sudanese cohort of OSCC patients and to explore patterns of diversities associated with overall survival (OS).Materials and MethodsUnstimulated saliva samples (n = 72) were collected from patients diagnosed with OSCC (n = 59) and from non-OSCC control volunteers (n = 13). DNA was extracted using a combined enzymatic–mechanical extraction protocol. The salivary mycobiome was assessed using a next-generation sequencing (NGS)-based methodology by amplifying the ITS2 region. The impact of the abundance of different fungal genera on the survival of OSCC patients was analyzed using Kaplan–Meier and Cox regression survival analyses (SPPS).ResultsSixteen genera were identified exclusively in the saliva of OSCC patients. Candida, Malassezia, Saccharomyces, Aspergillus, and Cyberlindnera were the most relatively abundant fungal genera in both groups and showed higher abundance in OSCC patients. Kaplan–Meier survival analysis showed higher salivary carriage of the Candida genus significantly associated with poor OS of OSCC patients (Breslow test: p = 0.043). In contrast, the higher salivary carriage of Malassezia showed a significant association with favorable OS in OSCC patients (Breslow test: p = 0.039). The Cox proportional hazards multiple regression model was applied to adjust the salivary carriage of both Candida and Malassezia according to age (p = 0.029) and identified the genus Malassezia as an independent predictor of OS (hazard ratio = 0.383, 95% CI = 0.16–0.93, p = 0.03).ConclusionThe fungal compositional patterns in saliva from OSCC patients were different from those of individuals without OSCC. The fungal genus Malassezia was identified as a putative prognostic biomarker and therapeutic target for OSCC.

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OBJECTIVE To evaluate archival tissue specimens from bladder tumours and seek molecular changes in samples collected over seven decades previously, as although the frequencies of some cancer types have remained stable during the last 50 years, the incidence of others, including bladder tumours, has increased significantly, and molecular analyses of bladder cancer over periods with an increasing incidence are of interest as the findings might reflect varying external influences. MATERIALS AND METHODS Immunohistochemical staining with the biological markers p53 protein, p16 protein, epidermal growth factor receptor (EGFR), cytokeratin 7 and high molecular weight 34βE12 cytokeratin (HMW‐cytokeratin, characteristic of basal cells) was used on archival, paraffin wax‐embedded autopsy/biopsy tissue material collected from 144 patients with invasive bladder cancer (World Health Organisation grade II and III). The cases were selected from the periods 1932–48, 1950–59, 1960–70 and 1990–2004. Control immunohistochemistry was done on available normal tissue (i.e. connective and fatty tissue, heart, lungs and normal urinary bladder epithelium) obtained from the autopsies. RESULTS The normal tissues were all largely negative for EGFR, had <1% positively stained nuclei for p53 and strong positive reactions for p16, and in epithelial tissues the two cytokeratins were detected. The positive scores for HMW‐cytokeratin in the tumour tissue decreased significantly from ≈ 90% to 30% over the 70 years. For p53 there was a higher fraction of positive scores (borderline significant) with time. The p16‐positive tumours showed no significant variation, with the highest frequency of positive scores in recent years. Overexpression of EGFR in the tumours was significantly correlated with the occurrence of HMW‐cytokeratin and decreased from ≈ 85% to 65% (not significant), with the lowest frequency in the samples from 1990 to 2004. Autolysis after death or long storage periods did not compromise good quality in the histochemical analyses of the autopsy tissue. CONCLUSION The higher frequency of HMW‐cytokeratin, lower p53 accumulation and more EGFR expression in grade II and III urinary bladder carcinomas from the 1930s could indicate different phenotypes in bladder cancer during this 70‐year period. The successful detection of these protein markers in old archival material allows larger retrospective studies that might increase the understanding of molecular carcinogenesis in bladder cancer.

BackgroundThe purpose of this study was to evaluate invasive and metastatic potential of urothelial cancer by investigating differential expression of various clock genes/proteins participating in the 24 h circadian rhythms and to compare these gene expressions with transcription of other cancer-associated genes.MethodsTwenty seven paired samples of tumour and benign tissue collected from patients who underwent cystectomy were analysed and compared to 15 samples of normal bladder tissue taken from patients who underwent cystoscopy for benign prostate hyperplasia (unrelated donors). Immunohistochemical analyses were made for clock and clock-related proteins. In addition, the gene-expression levels of 22 genes (clock genes, casein kinases, oncogenes, tumour suppressor genes and cytokeratins) were analysed by real-time quantitative PCR (qPCR).ResultsConsiderable up- or down-regulation and altered cellular distribution of different clock proteins, a reduction of casein kinase1A1 (CSNK1A1) and increase of casein kinase alpha 1 E (CSNK1E) were found. The pattern was significantly correlated with simultaneous up-regulation of stimulatory tumour markers, and a down-regulation of several suppressor genes. The pattern was mainly seen in aneuploid high-grade cancers. Considerable alterations were also found in the neighbouring bladder mucosa.ConclusionsThe close correlation between altered expression of various clock genes and common tumour markers in urothelial cancer indicates that disturbed function in the cellular clock work may be an important additional mechanism contributing to cancer progression and malignant behaviour.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2580-y) contains supplementary material, which is available to authorized users.