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We measured soil respiration during two winters in three different ecotypes of the BOREAS northern study area. The production of CO2was continuous throughout the winter and, when totaled for the winter of 1994–1995, was equivalent to the release of ∼40–55 g C/m2from the soil surface. As soils cooled in the early winter, the CO2 production rate decreased in a manner that appeared to be exponentially related to shallow soil temperatures. This exponential relationship was not observed when soils began to warm, possibly indicating that there may be additional or different processes responsible for increased CO2 production during winter warming events. We also measured CO2 concentrations in soil gas and the Δ14C of the soil CO2. These measurements show that the CO2 produced in winter is not simply the return to the atmosphere of the carbon fixed during the previous growing season. We suggest that the wintertime production of CO2 originates, at least in part, from the decomposition of old organic carbon stored at depth in the soil.

Introduction: Oral tongue squamous cell carcinoma (OTSCC) is the most common cancer of the oral cavity. Contradictory results have been observed on the involvement of herpes simplex virus 1 (HSV-1) in oral squamous cell carcinomas. Here, we aimed to study the predominance of HSV-1 or HSV-2 in oral HSV infections and to investigate the presence of HSV-1 in OTSCC and its effect on carcinoma cell viability and invasion. Methods: The distribution of HSV types one and two in diagnostic samples taken from suspected oral HSV infections was determined from the Helsinki University Hospital Laboratory database. We then analysed 67 OTSCC samples for HSV-1 infection using immunohistochemical staining. We further tested the effects of HSV-1 using six concentrations (0.00001-1.0 multiplicity of infection [MOI]) on viability and two concentrations (0.001 and 0.1 MOI) on invasion of highly invasive metastatic HSC-3 and less invasive primary SCC-25 OTSCC cell lines using MTT and Myogel-coated Transwell invasion assays. Results: Altogether 321 oropharyngeal samples were diagnosed positive for HSV during the study period. HSV-1 was the predominant (97.8%) HSV type compared with HSV-2 (detected in 2.2% of samples). HSV-1 was also detected in 24% of the OTSCC samples and had no association with patient survival or recurrence. OTSCC cells were viable even after 6 days with low viral load (0.00001, 0.0001, 0.001 MOI) of HSV-1. In both cell lines, 0.001 MOI did not affect cell invasion. However, 0.1 MOI significantly reduced cell invasion in HSC-3 cells. Discussion: HSV-1 infection is predominant compared with HSV-2 in the oral cavity. HSV-1 is detected in OTSCC samples without clinical significance, and OTSCC cell survival or invasion was not affected at low doses of HSV-1., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Koivikko, Rodrigues, Vehviläinen, Hyvönen, Sundquist, Arffman, Al-Samadi, Välimaa, Salo and Risteli.)

Wetland soil stocks are important global repositories of carbon (C) but are difficult to quantify and model due to varying sampling protocols, and geomorphic/spatio-temporal discontinuity. Merging scales of soil-survey spatial extents with wetland-specific point-based data offers an explicit, empirical and updatable improvement for regional and continental scale soil C stock assessments. Agency-collected and community-contributed soil datasets were compared for representativeness and bias, with the goal of producing a harmonized national map of wetland soil C stocks with error quantification for wetland areas of the conterminous United States (CONUS) identified by the USGS National Landcover Change Dataset. This allowed an empirical predictive model of SOC density to be applied across the entire CONUS using relational %OC distribution alone. A broken-stick quantile-regression model identified %OC with its relatively high analytical confidence as a key predictor of SOC density in soil segments; soils less than 6% OC (hereafter, mineral wetland soils, 85% of the dataset) had a strong linear relationship of %OC to SOC density (RMSE = 0.0059, ~4% mean RMSE) and soils greater than 6% OC (organic wetland soils, 15% of the dataset) had virtually no predictive relationship of %OC to SOC density (RMSE = 0.0348 g C cm -3 , ~56% mean RMSE). Disaggregation by vegetation type, or region did not alter the breakpoint significantly (6% OC) nor improve model accuracies for inland and tidal wetlands. Similarly, SOC stocks in tidal wetlands were related to %OC, but without a mappable product for disaggregation to improve accuracy by soil class, region or depth. Our layered, harmonized CONUS wetland soil maps revised wetland SOC stock estimates downward by 24% (9.5 vs. 12.5Pg C) with the overestimation being entirely an issue of inland, organic wetland soils, (35% lower than SSURGO-derived SOC stocks). Further, SSURGO underestimated soil carbon stocks at depth, as modeled wetland SOC stocks for organic-rich soils showed significant preservation downcore in the NWCA dataset (<3% loss between 0-30 cm and 30-100 cm depths) in contrast to mineral-rich soils (37% downcore stock loss). Future CONUS wetland soil C assessments will benefit from focused attention on improved organic wetland soil measurements, land history, and spatial representativeness.

We describe a physics-based learning model for predicting the immunogenicity of cytotoxic T lymphocyte (CTL) epitopes derived from diverse pathogens including SARS-CoV-2. The model was trained and optimized on the relative immunodominance of CTL epitopes in human immunodeficiency virus infection. Its accuracy was tested against experimental data from patients with COVID-19. Our model predicts that only some SARS-CoV-2 epitopes predicted to bind to HLA molecules are immunogenic. The immunogenic CTL epitopes across all SARS-CoV-2 proteins are predicted to provide broad population coverage, but those from the SARS-CoV-2 spike protein alone are unlikely to do so. Our model also predicts that several immunogenic SARS-CoV-2 CTL epitopes are identical to seasonal coronaviruses circulating in the population and such cross-reactive CD8 + T cells can indeed be detected in prepandemic blood donors, suggesting that some level of CTL immunity against COVID-19 may be present in some individuals before SARS-CoV-2 infection., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)

Oral tongue squamous cell carcinoma (OTSCC), the most common cancer in the oral cavity, is aggressive and its incidence is increasing globally. Human host defense cationic antimicrobial peptide‑18/antimicrobial peptide leucine‑leucine‑37 (hCAP18/LL‑37) plays a complex role in various types of cancers. In the present study, we characterized the effects of exogenous LL‑37 on three OTSCC cell lines and determined the expression of hCAP18/LL‑37 in oral dysplastic and OTSCC patient samples. Our data revealed that LL‑37, especially in high doses, mostly reduced the proliferation of OTSCC cells, but the effect was fluctuating. However, LL‑37 stimulated the migration and invasion of OTSCC cells. The high dose of LL‑37 also increased the amount of total epidermal growth factor receptor (EGFR) probably due to stabilization of the receptor to the plasma membrane. However, activation of EGFR downstream pathways was mostly decreased. Our immunohistochemical analysis showed that the hCAP18/LL‑37 expression was higher in normal/mild dysplasia than in moderate/severe dysplasia and OTSCC. The hCAP18/LL‑37 expression did not correlate with clinicopathological features or outcome of OTSCC patients. Our data suggest that LL‑37 has a fluctuating effect on proliferation, migration and invasion of OTSCC cells, but it does not seem to play a role in the progression of OTSCC.

Background: Oral tongue squamous cell carcinoma (SCC) is characterized by early metastasis and poor prognosis. Interleukin-17F (IL-17F) plays a protective role in many tumors. However, IL-17F expression in oral tongue SCC tissue has not been investigated., Methods: Immunostaining of 83 oral tongue SCC specimens and blinded-scoring were used to map IL-17F expression, location, and distribution. Survival curves were constructed according to Kaplan-Meier method. The Cox proportional hazard model was applied for univariate and multivariate survival analyses., Results: Mast cells are the major source of IL-17F in oral tongue SCC. In multivariate analysis, only the extracellular mast cell-derived IL-17F at the tumor invasion front was associated with better disease-specific survival in patients with all-stages and early-stages of oral tongue SCC., Conclusion: Extracellular mast cell-derived IL-17F is antitumorigenic in oral tongue SCC. It separates patients with early-stage disease who are at high risk from patients who are at low risk. Furthermore, when analyzing tentative prognostic molecules, we conclude that in addition to the staining intensity, attention must be paid to the cellular source, distribution, and location of the molecule., (© 2018 Wiley Periodicals, Inc.)

Different regions of oral squamous cell carcinoma (OSCC) have particular histopathological and molecular characteristics limiting the standard tumor-node-metastasis prognosis classification. Therefore, defining biological signatures that allow assessing the prognostic outcomes for OSCC patients would be of great clinical significance. Using histopathology-guided discovery proteomics, we analyze neoplastic islands and stroma from the invasive tumor front (ITF) and inner tumor to identify differentially expressed proteins. Potential signature proteins are prioritized and further investigated by immunohistochemistry (IHC) and targeted proteomics. IHC indicates low expression of cystatin-B in neoplastic islands from the ITF as an independent marker for local recurrence. Targeted proteomics analysis of the prioritized proteins in saliva, combined with machine-learning methods, highlights a peptide-based signature as the most powerful predictor to distinguish patients with and without lymph node metastasis. In summary, we identify a robust signature, which may enhance prognostic decisions in OSCC and better guide treatment to reduce tumor recurrence or lymph node metastasis.

It is of great clinical importance to identify simple prognostic markers from preoperative biopsies that could guide treatment planning. Here, we compared tumor budding (B), depth of invasion (D), and the combined scores (i.e., budding and depth of invasion (BD) histopathologic model) in preoperative biopsies and the corresponding postoperative specimens of oral tongue squamous cell carcinoma (OTSCC). Tumor budding and depth of invasion were evaluated in the pre- and postoperative samples from 100 patients treated for OTSCC. Sensitivity and specificity statistics were used. Our results showed statistically significant (P < 0.001) relationship between pre- and postoperative BD scores. There was an agreement between the pre- and postoperative BD model scores in 83 cases (83%) with 57.1% sensitivity (95% CI 39.4 to 73.7%) and 96.9% specificity (95% CI 89.3 to 99.6%). Our findings suggest that the BD model, analyzed from representative biopsies, could be used for the treatment planning of OTSCC.

Background: Rho-associated coiled-coil kinase 2 (ROCK2) is an oncoprotein that controls cytoskeleton organization and acts as prognostic marker in different types of solid tumors. ROCK2 overexpression is also observed in cancer-associated fibroblasts (CAF), which suggests its relevance within the tumor microenvironment. This study aimed to access the prognostic value of ROCK2 in oral squamous cell carcinomas (OSCCs) and its association with CAF density., Methods: Rho-associated coiled-coil kinase 2 immunohistochemical analysis was applied in 93 OSCC samples from 2 centers in Brazil and Finland. The samples were also stained for isoform α of smooth muscle actin (α-SMA) to characterize the presence of CAF in the tumor stroma. Clinicopathological associations were analyzed using Chi-squared test, survival curves were constructed according to the Kaplan-Meier method, and Cox proportional hazard model was applied for multivariate survival analysis., Results: Advanced clinical stage (P = .002) and increased density of CAF (P = .002) were significantly associated with high ROCK2 expression. The high expression of ROCK2 was also associated with shortened disease-specific survival (HR: 2.22, 95% CI: 1.15-4.38, P = .04), but the association did not withstand the Cox multivariate survival analysis., Conclusions: The findings suggest that high ROCK2 expression in OSCC is associated with advanced disease and follows the increase in CAF density, which may be important for tumor progression., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Alongside cancer cells, tumours exhibit a complex stroma containing a repertoire of cells, matrix molecules and soluble factors that actively crosstalk between each other. Recognition of this multifaceted concept of the tumour microenvironment (TME) calls for authentic TME mimetics to study cancer in vitro Traditionally, tumourigenesis has been investigated in non-human, three-dimensional rat type I collagen containing organotypic discs or by means of mouse sarcoma-derived gel, such as Matrigel ® However, the molecular compositions of these simplified assays do not properly simulate human TME. Here, we review the main properties and benefits of using human leiomyoma discs and their matrix Myogel for in vitro assays. Myoma discs are practical for investigating the invasion of cancer cells, as are cocultures of cancer and stromal cells in a stiff, hypoxic TME mimetic. Myoma discs contain soluble factors and matrix molecules commonly present in neoplastic stroma. In Transwell, IncuCyte, spheroid and sandwich assays, cancer cells move faster and form larger colonies in Myogel than in Matrigel ® Additionally, Myogel can replace Matrigel ® in hanging-drop and tube-formation assays. Myogel also suits three-dimensional drug testing and extracellular vesicle interactions. To conclude, we describe the application of our myoma-derived matrices in 3D in vitro cancer assays.This article is part of the discussion meeting issue 'Extracellular vesicles and the tumour microenvironment'., (© 2017 The Authors.)

Background: Oral tongue squamous cell carcinoma (OTSCC) metastasises early, especially to regional lymph nodes. There is an ongoing debate on which early stage (T1-T2N0) patients should be treated with elective neck dissection. We need prognosticators for early stage tongue cancer., Methods: Mice immunisation with human mesenchymal stromal cells resulted in production of antibodies against tenascin-C (TNC) and fibronectin (FN), which were used to stain 178 (98 early stage), oral tongue squamous cell carcinoma samples. Tenascin-C and FN expression in the stroma (negative, moderate or abundant) and tumour cells (negative or positive) were assessed. Similar staining was obtained using corresponding commercial antibodies., Results: Expression of TNC and FN in the stroma, but not in the tumour cells, proved to be excellent prognosticators both in all stages and in early stage cases. Among early stages, when stromal TNC was negative, the 5-year survival rate was 88%. Correspondingly, when FN was negative, no cancer deaths were observed. Five-year survival rates for abundant expression of TNC and FN were 43% and 25%, respectively., Conclusions: Stromal TNC and, especially, FN expressions differentiate patients into low- and high-risk groups. Surgery alone of early stage primary tumours might be adequate when stromal FN is negative. Aggressive treatments should be considered when both TNC and FN are abundant.

The invasion of carcinoma cells is a crucial feature in carcinogenesis. The penetration efficiency not only depends on the cancer cells, but also on the composition of the tumor microenvironment. Our group has developed a 3D invasion assay based on human uterine leiomyoma tissue. Here we tested whether human, porcine, mouse or rat hearts as well as porcine tongue tissues could be similarly used to study carcinoma cell invasion in vitro. Three invasive human oral tongue squamous cell carcinoma (HSC-3, SCC-25 and SCC-15), melanoma (G-361) and ductal breast adenocarcinoma (MDA-MB-231) cell lines, and co-cultures of HSC-3 and carcinoma-associated or normal oral fibroblasts were assayed. Myoma tissue, both native and lyophilized, promoted invasion and growth of the cancer cells. However, the healthy heart or tongue matrices were unable to induce the invasion of any type of cancer cells tested. Moreover, when studied in more detail, small molecular weight fragments derived from heart tissue rinsing media inhibited HSC-3 horizontal migration. Proteome analysis of myoma rinsing media, on the other hand, revealed migration enhancing factors. These results highlight the important role of matrix composition for cancer invasion studies in vitro and further demonstrate the unique properties of human myoma organotypic model., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: The composition of the matrix molecules is important in in vitro cell culture experiments of e.g. human cancer invasion and vessel formation. Currently, the mouse Engelbreth-Holm-Swarm (EHS) sarcoma-derived products, such as Matrigel®, are the most commonly used tumor microenvironment (TME) mimicking matrices for experimental studies. However, since Matrigel® is non-human in origin, its molecular composition does not accurately simulate human TME. We have previously described a solid 3D organotypic myoma disc invasion assay, which is derived from human uterus benign leiomyoma tumor. Here, we describe the preparation and analyses of a processed, gelatinous leiomyoma matrix, named Myogel., Methods: A total protein extract, Myogel, was formulated from myoma. The protein contents of Myogel were characterized and its composition and properties compared with a commercial mouse Matrigel®. Myogel was tested and compared to Matrigel® in human cell adhesion, migration, invasion, colony formation, spheroid culture and vessel formation experiments, as well as in a 3D hanging drop video image analysis., Results: We demonstrated that only 34% of Myogel's molecular content was similar to Matrigel®. All test results showed that Myogel was comparable with Matrigel®, and when mixed with low-melting agarose (Myogel-LMA) it was superior to Matrigel® in in vitro Transwell® invasion and capillary formation assays., Conclusions: In conclusion, we have developed a novel Myogel TME matrix, which is recommended for in vitro human cell culture experiments since it closely mimics the human tumor microenvironment of solid cancers.

Oral tongue squamous cell carcinoma (OTSCC) has a high mortality rate and the incidence is rising worldwide. Despite advances in treatment, the disease lacks specific prognostic markers and treatment modality. The spreading of OTSCC is dependent on the tumor microenvironment and involves tumor-associated macrophages (TAMs). Although the presence of TAMs is associated with poor prognosis in OTSCC, the specific mechanisms underlying this are still unknown. The aim here was to investigate the effect of macrophages (Mfs) on HSC-3 tongue carcinoma cells and NF-kappaB activity. We polarized THP-1 cells to M1 (inflammatory), M2 (TAM-like) and R848 (imidazoquinoline-treated) type Mfs. We then investigated the effect of Mfs on HSC-3 cell migration and NF-kappaB activity, cytokine production and invasion using several different in vitro migration models, a human 3D tissue invasion model, antibody arrays, confocal microscopy, immunohistochemistry and a mouse invasion model. We found that in co-culture studies all types of Mfs fused with HSC-3 cells, a process which was partially due to efferocytosis. HSC-3 cells induced expression of epidermal growth factor and transforming growth factor-beta in co-cultures with M2 Mfs. Direct cell-cell contact between M2 Mfs and HSC-3 cells induced migration and invasion of HSC-3 cells while M1 Mfs reduced HSC-3 cell invasion. M2 Mfs had an excess of NF-kappaB p50 subunit and a lack of p65 subunits both in the presence and absence of HSC-3 cells, indicating dysregulation and pro-tumorigenic NF-kappaB activation. TAM-like cells were abundantly present in close vicinity to carcinoma cells in OTSCC patient samples. We conclude that M2 Mfs/TAMs have an important role in OTSCC regulating adhesion, migration, invasion and cytokine production of carcinoma cells favouring tumor growth. These results demonstrate that OTSCC patients could benefit from therapies targeting TAMs, polarizing TAM-like M2 Mfs to inflammatory macrophages and modulating NF-kappaB activity.

Invasion is an important hallmark of cancer involving interactions between the tumor microenvironment and the cancer cells. Hypoxia, low oxygen level, is related to increased invasion and metastasis in many cancers. The aim was to elucidate the effect of hypoxia on invasion of oral squamous cell carcinoma cells (OSCCs), and the applicability of a novel 3-dimentional myoma organotypic invasion model in hypoxia experiments. OSCC cell lines (primary oral carcinoma derived cells UT-SCC-43A, recurrent oral carcinoma cells UT-SCC-43B and aggressive tongue carcinoma cells HSC-3) were studied for their migration and invasion capabilities under normoxia, hypoxia, and in the presence a hypoxia-mimicker cobalt chloride. As expected, the recurrent UT-SCC-43B cells were significantly more aggressive than the primary tumor derived cells. In contrast to tongue carcinoma HSC-3 cells, they only mildly responded to hypoxia in the migration or invasion assays, indicating a cell line specific response of hypoxia on the invasive potential. The modification of the organotypic human tissue-derived matrix via the removal of various yet unidentified soluble factors by rinsing the tissue resulting in stripped matrix substantially changed the invasion pattern of HSC-3 cells and the outcomes of hypoxic treatments. Only in the stripped tissue hypoxia significantly increased invasion, whereas in native intact tissue the induced invasion was not observed. This demonstrates the importance of the soluble factors to the invasion pattern and to the hypoxia response. A metastasis and poor prognosis marker, hypoxia-regulated lysyl oxidase (LOX), was present in the myoma tissue, but could be removed by rinsing. The inhibition of LOX resulted in a decrease in invasion area, but only very mildly in invasion depth. Thus, it may have a role in the modulation of the invasion pattern. Another hypoxia-related poor prognosis marker carbonic anhydrase 9 (CAIX) was induced in HSC-3 cells both by the hypoxic exposure and interestingly in invading HSC-3 cells inside the tissue even in normoxic conditions. In conclusion, this suggests that the intact myoma organotypic model offers optimally hypoxic surroundings, thus being an excellent human tumor microenvironment mimicker., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Deglaciation of the Laurentide Ice Sheet in North America was accompanied by sequestration of organic carbon in newly exposed soils. The greatest rate of land exposure occurred around 12,000 to 8,000 years ago, and the greatest increase in the rate of carbon sequestration by soils occurred from 8,000 to 4,000 years ago. Sequestration of carbon in deglaciated peat lands continues today, and a steady state has not been reached. The natural rate of carbon sequestration in soils, however, is small relative to the rate of anthropogenic carbon dioxide production.

A nationwide system for monitoring occupational exposure to a wide range of carcinogens has been in operation in Finland since 1979. The primary aim of the system is to lead to the identification, evaluation, and eventual elimination of the exposures. The number of exposed workers reported to the register was about 20,000 out of the work force of 2.3 million in 1979-1984. The most common exposures were chromates, nickel and its inorganic compounds, and asbestos. Data are presented to show that the system has been at least partially successful in decreasing exposures at work places. As an example, we discuss the decrease in the use of hydrazine, which was previously widely used as an anticorrosive agent at power plants. The statistical quality of the system is discussed, and possibilities for future research uses of the computerized data base are outlined.