Penile Cancers Attributed to Human Papillomavirus Are Associated with Improved Survival for Node-positive Patients. Findings from a Norwegian Cohort Study Spanning 50 Years

BACKGROUND

Human papillomavirus (HPV) infection is a risk factor for the development of penile squamous cell carcinoma (PSCC). It remains inconclusive whether HPV-related PSCC has a different prognosis from non-HPV-related PSCC.

OBJECTIVE

To investigate the relationship between HPV status and survival as well as temporal changes in the proportion of HPV-related PSCC.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort of 277 patients treated in Norway between 1973 and 2022 was investigated for HPV DNA in tumor tissue. Clinicopathological variables and disease course were registered.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier curves and Cox regression were used to investigate the determinants of cancer-specific survival (CSS). The chi-square test for trend in proportions enabled investigation of temporal changes in the HPV-related proportion of PSCC patients treated in Western Norway (n = 211).

RESULTS AND LIMITATIONS

HPV DNA was detected in tumor tissue from 131 (47%) patients. Stratified by HPV status, 5-yr CSS did not differ between groups (p = 0.37). When investigating only node-positive patients, however, presence of HPV DNA was an independent predictor of better survival in multivariable Cox regression after adjustment for age, nodal stage, and adjuvant therapy (hazard ratio 0.54, 95% confidence interval: [0.30-0.99], p = 0.04). In cases from Western Norway, an increasing proportion of HPV-related cases over time was found (p = 0.01). The main limitation is the retrospective study design.

CONCLUSIONS

HPV DNA in tumor tissue was associated with significantly better CSS for node-positive patients. The proportion of HPV DNA-positive PSCC has increased significantly in Western Norway over the past 50 yr.

PATIENT SUMMARY

We investigated the impact of human papillomavirus (HPV) on the survival of penile cancer patients treated over a 50-yr period in Norway. We found that for patients with lymph node metastasis, survival was better for HPV-related cases. We also found that the proportion of cases due to HPV has increased in Western Norway.

Loss of S100A14 expression at the tumor-invading front correlates with poor differentiation and worse prognosis in oral squamous cell carcinoma

BACKGROUND

We previously showed a tumor-suppressive function of S100A14 in oral squamous cell carcinoma (OSCC). This study aimed to examine the prognostic significance and differentiation-related function of S100A14 in OSCC.

METHODS

S100A14 expression was examined in 170 OSCCs from Norwegian and Nepalese populations using immunohistochemistry. Pro-differentiation function was investigated by overexpressing and silencing S100A14 expression in OSCC-derived cells. External transcriptomic datasets were used to validate association between S100A14 and differentiation markers in OSCC.

RESULT

Loss of S100A14 expression at the invading tumor fronts significantly correlated with poor differentiation and reduced 10-years survival of OSCC-patients. Multivariate Cox analysis identified S100A14 to be an independent prognostic factor. Modulation of S100A14 expression in OSCC-derived cells positively correlated with the expression of differentiation markers. Analysis of external datasets supported the pro-differentiation function of S100A14.

CONCLUSION

These results indicate that S100A14 is a pro-differentiation protein and its expression might be useful as a prognostic marker in OSCC.

In Vivo Host Response and Degradation of Copolymer Scaffolds Functionalized with Nanodiamonds and Bone Morphogenetic Protein 2

The aim is to evaluate the effect of modifying poly[(l-lactide)-co-(ε-caprolactone)] scaffolds (PLCL) with nanodiamonds (nDP) or with nDP+physisorbed BMP-2 (nDP+BMP-2) on in vivo host tissue response and degradation. The scaffolds are implanted subcutaneously in Balb/c mice and retrieved after 1, 8, and 27 weeks. Molecular weight analysis shows that modified scaffolds degrade faster than the unmodified. Gene analysis at week 1 shows highest expression of proinflammatory markers around nDP scaffolds; although the presence of inflammatory cells and foreign body giant cells is more prominent around the PLCL. Tissue regeneration markers are highly expressed in the nDP+BMP-2 scaffolds at week 8. A fibrous capsule is detectable by week 8, thinnest around nDP scaffolds and at week 27 thickest around PLCL scaffolds. mRNA levels of ALP, COL1α2, and ANGPT1 are significantly upregulating in the nDP+BMP-2 scaffolds at week 1 with ectopic bone seen at week 8. Even when almost 90% of the scaffold is degraded at week 27, nDP are observable at implantation areas without adverse effects. In conclusion, modifying PLCL scaffolds with nDP does not aggravate the host response and physisorbed BMP-2 delivery attenuates inflammation while lowering the dose of BMP-2 to a relatively safe and economical level.

Human oral cancer cells with increasing tumorigenic abilities exhibit higher effective membrane capacitance

OBJECTIVE

Although cells with tumorigenic/stem cell-like properties have been identified in many cancers, including oral squamous cell carcinoma (OSCC), their isolation and characterisation is still at early stages. The aim of this study is to characterise the electrophysiological properties of OSCC cells with different tumorigenic properties in order to establish if a correlation exists between tumorigenicity and cellular electrical characteristics.

MATERIALS AND METHODS

Rapid adherence to collagen IV was used as a non-invasive, functional method to isolate subsets of cells with different tumorigenic abilities from one oral dysplastic and three OSCC-derived cell lines. The cell subsets identified and isolated using this method were further investigated using dielectrophoresis, a label-free method to determine their electrophysiological parameters. Cell membrane morphology was investigated using scanning electron microscopy (SEM) and modulated by use of 4-methylumbelliferone (4-MU).

RESULTS

Rapid adherent cells (RAC) to collagen IV, enriched for increased tumorigenic ability, had significantly higher effective membrane capacitance than middle (MAC) and late (LAC) adherent cells. SEM showed that, in contrast to MAC and LAC, RAC displayed a rough surface, extremely rich in cellular protrusions. Treatment with 4-MU dramatically altered RAC membrane morphology by causing loss of filopodia, and significantly decreased their membrane capacitance, indicating that the highest membrane capacitance found in RAC was due to their cell membrane morphology.

CONCLUSION

This is the first study showing that OSCC cells with higher tumour formation ability exhibit higher effective membrane capacitance than cells that are less tumorigenic. OSSC cells with different tumorigenic ability possessed different electrophysiological properties mostly due to their differences in the cell membrane morphology. These results suggest that dielectrophoresis could potentially used in the future for reliable, label-free isolation of putative tumorigenic cells.

Human bone marrow mesenchymal stem cells induce collagen production and tongue cancer invasion

Tumor microenvironment (TME) is an active player in carcinogenesis and changes in its composition modify cancer growth. Carcinoma-associated fibroblasts, bone marrow-derived multipotent mesenchymal stem cells (BMMSCs), and inflammatory cells can all affect the composition of TME leading to changes in proliferation, invasion and metastasis formation of carcinoma cells. In this study, we confirmed an interaction between BMMSCs and oral tongue squamous cell carcinoma (OTSCC) cells by analyzing the invasion progression and gene expression pattern. In a 3-dimensional myoma organotypic invasion model the presence of BMMSCs inhibited the proliferation but increased the invasion of OTSCC cells. Furthermore, the signals originating from OTSCC cells up-regulated the expression of inflammatory chemokines by BMMSCs, whereas BMMSC products induced the expression of known invasion linked molecules by carcinoma cells. Particularly, after the cell-cell interactions, the chemokine CCL5 was abundantly secreted from BMMSCs and a function blocking antibody against CCL5 inhibited BMMSC enhanced cancer invasion area. However, CCL5 blocking antibody did not inhibit the depth of invasion. Additionally, after exposure to BMMSCs, the expression of type I collagen mRNA in OTSCC cells was markedly up-regulated. Interestingly, also high expression of type I collagen N-terminal propeptide (PINP) in vivo correlated with the cancer-specific mortality of OTSCC patients, whereas there was no association between cancer tissue CCL5 levels and the clinical parameters. In conclusion, our results suggest that the interaction between BMMSC and carcinoma cells induce cytokine and matrix molecule expression, of which high level of type I collagen production correlates with the prognosis of OTSCC patients.

Successful triple immunoenzymatic method employing primary antibodies from same species and same immunoglobulin subclass

Protocols for immunohistochemical (IHC) detection of multiple antigens in the same tissue sections have been developed using primary antibodies directly conjugated to different enzymes or fluorochromes, or ones that have been raised in different species, or from different immunoglobulin (Ig) classes or subclasses. For antibodies lacking such dissimilarities, very few proposals have been published with varying degrees of generalizability. In this report we present a successful triple IHC protocol engaging three unconjugated monoclonal primary antibodies raised in the same species and of the same Ig subclass. Compared to other methods, our results showed that denaturation of the preceding reaction complex by microwave heating, combined with additional suppression of enzyme activity, enabled the detection of all three reactions by using the same detection system, with no cross reaction observed. Moreover, expression patterns of each of the three antigens in the triple stained sections, was found to be similar to the pattern observed when single staining was performed. Unlike previous reports, no damage of targeted antigens or tissues did occur following this protocol. Furthermore, the contrast of the colors employed was investigated by computerized color deconvolution, and the three reactions products were successfully separated into three individual images that could be used for further objective quantification.

The use of salivary cytokines as a screening tool for oral squamous cell carcinoma : A review of the literature

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck cancer. The 5-year survival rate has remained below 50% over the last two decades, and new tools for early diagnosis are needed. Saliva has been used for diagnosis of several systemic diseases, and its use for diagnosis of OSCC has been sought extensively. Among the many salivary analytes for diagnosis of OSCC, accumulating evidences indicate the possibility of using salivary cytokines. Overproduction of proinflammatory, proangiogenic cytokines by OSCC cells has been reported, and their role in tumor progression and angiogenesis is well established. However, many inflammatory conditions and immunological diseases could affect the levels of cytokines in serum and saliva. This article has reviewed publications in this matter, and some strengths and weaknesses have been pointed out. Conclusively, large-scale investigations are required for validation of the use of salivary cytokines for diagnosis of OSCC, with consideration to the influential role of periodontal inflammation in their levels.

In vitro reconstruction of human junctional and sulcular epithelium

BACKGROUND

The aim of this study was to develop and characterize standardized in vitro three-dimensional organotypic models of human junctional epithelium (JE) and sulcular epithelium (SE).

METHODS

Organotypic models were constructed by growing human normal gingival keratinocytes on top of collagen matrices populated with gingival fibroblasts (GF) or periodontal ligament fibroblasts (PLF). Tissues obtained were harvested at different time points and assessed for epithelial morphology, proliferation (Ki67), expression of JE-specific markers (ODAM and FDC-SP), cytokeratins (CK), transglutaminase, filaggrin, and basement membrane proteins (collagen IV and laminin1).

RESULTS

The epithelial component in 3- and 5-day organotypics showed limited differentiation and expressed Ki-67, ODAM, FDC-SP, CK 8, 13, 16, 19, and transglutaminase in a similar fashion to control JE samples. PLF supported better than GF expression of CK19 and suprabasal proliferation, although statistically significant only at day 5. Basement membrane proteins started to be deposited only from day 5. The rate of proliferating cells as well as the percentage of CK19-expressing cells decreased significantly in 7- and 9-day cultures. Day 7 organotypics presented higher number of epithelial cell layers, proliferating cells in suprabasal layers, and CK expression pattern similar to SE.

CONCLUSION

Both time in culture and fibroblast type had impact on epithelial phenotype. Five-day cultures with PLF are suggested as JE models, 7-day cultures with PLF or GF as SE models, while 9-day cultures with GF as gingival epithelium (GE) models. Such standard, reproducible models represent useful tools to study periodontal bacteria–host interactions in vitro.

Epithelial stem cells and malignancy

The renewal of normal epithelia depends on a small sub-population of cells, termed somatic stem cells, whose primary characteristic is an ability for indefinite self-renewal. Evidence is accumulating that the growth of tumours similarly depends on a sub-population of malignant stem cells, often termed tumour-initiating cells. Tumour-initiating sub-populations within solid tumours have been identified by their cell surface expression of various phenotypic markers and by their ability to regenerate tumours in immune-deficient mice. Cells with such clonogenic abilities differ consistently from the remainder of the cell population in cellular properties such as size, adhesiveness, dye exclusion, and patterns of gene expression. Sub-populations of malignant cells freshly isolated from tumours also show differing patterns of expression of molecules related to stem cell maintenance and asymmetric division. As the cells ultimately responsible for tumour renewal, malignant stem cells appear to form the necessary target of therapy but some findings indicate greater resistance of these cells to the induction of apoptotic cell death and their potential failure to respond effectively to standard therapeutic procedures. Of particular interest, cells with clonogenic properties and expression patterns similar to those of tumour-initiating cells in vivo persist in malignant cell lines and show similar apoptotic resistance. Cell lines may thus provide a model for analysis of malignant stem cell properties and may be useful for the development of appropriate methods for their elimination.

Khat induces G1-phase arrest and increased expression of stress-sensitive p53 and p16 proteins in normal human oral keratinocytes and fibroblasts

Khat is a psychostimulant plant used by over 10 million people daily, mainly in eastern Africa and the Middle East. Previous studies have suggested an association between khat use and oral lesions such as hyperkeratosis and oral cancer. This study investigated the effects of an extract of khat on primary normal human oral keratinocytes (NOK) and normal human oral fibroblasts (NOF). Low (sublethal) concentrations of khat inhibited the proliferation of both cell types in a dose-dependent and time-dependent manner. Both NOK and NOF treated with khat accumulated in the G1-phase of the cell cycle and showed increased expression of the stress-sensitive p53 protein after 24 h. Normal human oral keratinocytes showed a profound increase in p16(INK4A) (p16) after 24 h and showed morphological changes suggesting cell differentiation. Normal human oral fibroblasts showed growth inhibition and increased expression of p21(WAF1/CIP1) (p21) within 24 h. The concentrations of khat tested in this study were within the range of those found in the oral cavity of khat chewers. The results show that stress induced by khat modulates the cell cycle in oral keratinocytes and fibroblasts. It is further speculated whether khat could have similar effects in vivo, especially in keratinocytes.

Khat (Catha edulis) induces reactive oxygen species and apoptosis in normal human oral keratinocytes and fibroblasts

Khat chewing is widely practiced in Eastern Africa and the Middle East. Khat is genotoxic to cells within the oral mucosa, and several studies have suggested an association between khat use and oral lesions like hyperkeratosis and oral cancer. This study investigated the mechanism of khat-induced cytotoxicity using primary normal human oral keratinocytes (NOK) and fibroblasts (NOF). Khat induced rounding up of cells, plasma membrane blebbing, and condensation of nuclear chromatin within 3-6 h of exposure. The cells also showed externalization of phosphatidylserine and fragmentation of DNA. Morphological and biochemical features were compatible with cell death by apoptosis. Khat also induced an increase in cytosolic reactive oxygen species (ROS) and a depletion of intracellular glutathione (GSH) within 1 h of exposure. Antioxidants reduced ROS generation, GSH depletion and delayed the onset of cytotoxicity in both cell types. Generally, NOF cells were more sensitive to khat-induced cytotoxicity than NOK cells. These effects were elicited at concentrations of khat expected to occur in the oral cavity during khat chewing. In summary, khat induced apoptotic cell death in primary normal oral keratinocytes and fibroblasts by an early effect on mechanisms that regulate oxidative stress.

Cancer stem cells – new and potentially important targets for the therapy of oral squamous cell carcinoma

There is increasing evidence that the growth and spread of cancers is driven by a small subpopulation of cancer stem cells (CSCs) - the only cells that are capable of long-term self-renewal and generation of the phenotypically diverse tumour cell population. Current failure of cancer therapies may be due to their lesser effect on potentially quiescent CSCs which remain vital and retain their full capacity to repopulate the tumour. Treatment strategies for the elimination of cancer therefore need to consider the consequences of the presence of CSCs. However, the development of new CSC-targeted strategies is currently hindered by the lack of reliable markers for the identification of CSCs and the poor understanding of their behaviour and fate determinants. Recent studies of cell lines derived from oral squamous cell carcinoma (OSCC) indicate the presence of subpopulations of cells with phenotypic and behavioural characteristics corresponding to both normal epithelial stem cells and to cells capable of initiating tumours in vivo. The present review discusses the relevance to OSCC of current CSC concepts, the state of various methods for CSC identification, characterization and isolation (clonal functional assay, cell sorting based on surface markers or uptake of Hoechst dye), and possible new approaches to therapy.

Khat (Catha edulis)-induced apoptosis is inhibited by antagonists of caspase-1 and -8 in human leukaemia cells

Khat chewing is a widespread habit that has a deep-rooted sociocultural tradition in Africa and the Middle East. The biological effects of khat are inadequately investigated and controversial. For the first time, we show that an organic extract of khat induces a selective type of cell death having all morphological and biochemical features of apoptotic cell death. Khat extract was shown to contain the major alkaloid compounds cathinone and cathine. The compounds alone and in combination also induced apoptosis. Khat-induced apoptosis occurred synchronously in various human cell lines (HL-60, NB4, Jurkat) within 8 h of exposure. It was partially reversed after removal of khat and the effect was dependent on de novo protein synthesis, as demonstrated by cotreatment with cycloheximide. The cell death was blocked by the pan-caspase inhibitor Z-VAD-fmk, and also by submicromolar concentrations of Z-YVAD-fmk and Z-IETD-fmk, inhibitors of caspase-1 and -8, respectively. The 50% inhibition constant (IC(50)) for khat (200 microg ml(-1))-induced apoptosis by Z-VAD-fmk, Z-YVAD-fmk and Z-IETD-fmk was 8 x 10(-7) M as compared to 2 x 10(-8) M and 8 x 10(-8) M, respectively. Western blot analysis showed a specific cleavage of procaspase-3 in apoptotic cells, which was inhibited by Z-VAD-fmk. The cell death by khat was more sensitively induced in leukaemia cell lines than in human peripheral blood leukocytes. It is concluded that khat induces a rather swift and sensitive cell death by apoptosis through mechanisms involving activation of caspase-1, -3 and -8.