Untersuchung des Mikrotubuli-abhängigen Vesikeltransports und der Tubulin- Detyrosinierung in Aspergillus nidulans

Mikrotubuli sind hoch dynamischen Proteinfilamente, die neben der Formgebung an zahlreichen Transportprozessen beteiligt sind. Zu den Mikrotubuli-assoziierten Proteinen gehören neben den Motorproteinen, welche den Transport unterschiedlichster Transportgüter erfüllen, auch Enzyme, welche die Tubulin-Dimere posttranslational modifizieren. Die Tubulin-Detyrosinierung führt zu Defekten der Kernverteilung und verminderter Sporenproduktion

Human papillomavirus infection in healthy youth and in hypopharyngeal cancer

The aim of this thesis was to follow the prevalence of human papillomavirus in the oral cavity and in the cervix in youth during the period of 2008-2015, a period when HPV vaccination was gradually introduced to young girls in Sweden. In addition, we explored the prevalence of HPV in hypopharyngeal cancer during the period 2000-2012 on the basis that there has been an epidemic of HPV positive tonsillar and base of tongue cancer, which arise in locations with close physiological proximity to the hypopharynx. The main questions addressed were whether HPV prevalence is similar within different cohorts of Swedish youth, how the prevalence changes over time and after the introduction of the HPV vaccines, and if the increased proportion of HPV positive oropharyngeal cancer is mirrored also in hypopharyngeal cancer. Since the prevalence of oral and genital HPV previously observed at a Stockholm youth clinic was high during the period of 2008-2011, there was an opportunity to compare these data to the HPV prevalence in different geographical locations and at other time points. The strong Swedish tradition of biobanking granted access to a relatively large sample of hypopharyngeal cancers, and the high prevalence of HPV in oropharyngeal cancers in Sweden made it credible that HPV would also be present at detectable levels in hypopharyngeal cancer and make it possible to detect changes occurring in the HPV prevalence in this cancer type. To investigate these matters, oral and cervical samples were analyzed for the presence of HPV DNA, a questionnaire was used to investigate the sexual experiences of youth, and HPV DNA and p16 expression was analyzed in relation to survival in samples of hypopharyngeal cancer. In Paper I, we could show that oral HPV prevalence was significantly less common in high school students from a middle sized municipality in Sweden (1.8%) than what was observed in 2009-2011 in the Stockholm youth clinic(9.3%). In Paper II, we could show that there were no differences between HPV vaccinated and nonvaccinated women regarding condom use and self-reported STI history, however, vaccinated women were more likely to have had vaginal intercourse and one-night stands (p=0.005, and p=0.046, respectively). In Paper III, we found a low oral HPV prevalence also at the Stockholm youth clinic (1.4%) in 2013-2014 which was lower than what was previously observed at the same clinic (p=0.00001). Cervical HPV 16, 31 and 70 prevalence was now less common in vaccinated than in non-vaccinated individuals (p =0.0002, p=0.019, and p=0.006, respectively). In Paper IV, we expanded the cohort from paper 3 to also include samples from the fall of 2014 and the spring of 2015. Oral HPV prevalence remained low (1.5%) and cervical HPV 16, 31 and 6 were less common in vaccinated than in non-vaccinated women (p=0.0006, p=0.038 and p=0.009, respectively). In Paper V, we could show that the proportion of HPV positive cases of hypopharyngeal cancer have not increased in Stockholm and that p16 is a poor surrogate marker of active HPV infection in this cancer type

Tumor Infiltrating CD8+ and Foxp3+ Lymphocytes Correlate to Clinical Outcome and Human Papillomavirus (HPV) Status in Tonsillar Cancer

BACKGROUND: Human papillomavirus (HPV) is a causative factor for tonsillar squamous cell carcinoma (TSCC) and patients with HPV positive (HPV(+)) TSCC have a better clinical outcome than those with HPV negative (HPV(-)) TSCC. However, since not all patients with HPV(+) TSCC respond to treatment, additional biomarkers are needed together with HPV status to better predict response to therapy and to individualize treatment. For this purpose, we examined whether the number of tumor infiltrating cytotoxic and regulatory T-cells in TSCC correlated to HPV status and to clinical outcome. METHODS: Formalin fixed paraffin embedded TSCC, previously analysed for HPV DNA, derived from 83 patients, were divided into four groups depending on the HPV status of the tumor and clinical outcome. Tumors were stained by immunohistochemistry and evaluated for the number of infiltrating cytotoxic (CD8(+)) and regulatory (Foxp3(+)) T-cells. RESULTS: A high CD8(+) T-cell infiltration was significantly positively correlated to a good clinical outcome in both patients with HPV(+) and HPV(-) TSCC patients. Similarly, a high CD8(+)/Foxp3(+) TIL ratio was correlated to a 3-year disease free survival. Furthermore, HPV(+) TSCC had in comparison to HPV(-) TSCC, higher numbers of infiltrating CD8(+) and Foxp3(+) T-cells. CONCLUSIONS: In conclusion, a positive correlation between a high number of infiltrating CD8(+) cells and clinical outcome indicates that CD8(+) cells may contribute to a beneficial clinical outcome in TSCC patients, and may potentially serve as a biomarker. Likewise, the CD8(+)/Foxp3(+)cell ratio can potentially be used for the same purpose

Changes in Cervical Human Papillomavirus (HPV) Prevalence at a Youth Clinic in Stockholm, Sweden, a Decade After the Introduction of the HPV Vaccine

Aim: This study aimed to follow the impact of human papillomavirus (HPV) catch-up and vaccination on the very high cervical HPV-prevalence in women at a youth clinic in central Stockholm during the period 2008–2018.Background: 2008–2010, cervical HPV-prevalence (69.5%) and HPV16 prevalence (34.7%) were high in non-vaccinated women at a youth clinic in Stockholm. 2013–2015, after the introduction of the quadrivalent-Gardasil® HPV-vaccine, HPV16 and HPV6 prevalence had decreased. Here, cervical HPV-prevalence was investigated 10 years after primary sampling.Material and Methods: 2017–2018, 178 cervical swabs, from women aged 15–23 years old, were tested for 27 HPV types by a bead-based multiplex method. HPV-prevalence data were then related to vaccination status and age and compared to HPV-prevalence in 615 samples from 2008 to 2010 and 338 samples from 2013 to 2015 from the same clinic, and to HPV types in 143 cervical cancer cases during 2003–2008 in Stockholm.Results: The proportion of vaccinated women increased from 10.7% (2008–2010) to 82.1% (2017–2018). The prevalence of all 27 HPVs, all high-risk HPVs (HR-HPVs) and the combined presence of the quadrivalent-Gardasil® types HPV16, 18, 6, and 11, was lower in vaccinated compared to unvaccinated women (67.4 vs. 93.3%, p = 0.0031, 60.1 vs. 86.7%, p = 0.0057 and 5.8 vs. 26.7%, p = 0.002, respectively). Furthermore, HPV16 prevalence in non-vaccinated women 2017–2018 was lower than that in 2008–2010 (16.7 and 34.7%, respectively, p = 0.0471) and similar trends were observed for HPV18 and 11. In both vaccinated and non-vaccinated women, the most common non-quadrivalent-Gardasil® vaccine HR-HPV types were HPV39, 51, 52, 56, and 59. Together they accounted for around 9.8% of cervical cancer cases in Stockholm during 2003–2008, and their prevalence tended to have increased during 2017–2018 compared to 2008–2010.Conclusion: Quadrivalent-Gardasil® vaccination has decreased HPV-vaccine type prevalence significantly. However, non-vaccine HR-HPV types remain high in potentially high-risk women at a youth clinic in Stockholm

Human Papillomavirus and Tonsillar and Base of Tongue Cancer

In 2007, human papillomavirus (HPV) type 16 was recognized as a risk factor by the International Agency for Research on Cancer, for oropharyngeal squamous cell carcinoma (OSCC), where tonsillar and base of tongue cancer (TSCC and BOTSCC) dominate. Furthermore, patients with HPV-positive TSCC and BOTSCC, had a much better clinical outcome than those with corresponding HPV-negative cancer and other head and neck cancer. More specifically, survival was around 80% for HPV-positive TSCC and BOTSCC vs. 40% five-year disease free survival, for the corresponding HPV-negative tumors with conventional radiotherapy and surgery, while this could not be observed for HPV-positive OSCC at other sites. In addition, the past 20–40 years in many Western Countries, the incidence of HPV-positive TSCC and BOTSCC has risen, and >70% are men. This has resulted in a relative increase of patients with HPV-positive TSCC and BOTSCC that may not need the intensified chemo-radiotherapy (with many more severe debilitating side effects) often given today to patients with head and neck cancer. However, before tapering therapy, one needs to enable selection of patients for such treatment, by identifying clinical and molecular markers that together with HPV-positive status will better predict patient prognosis and response to therapy. To conclude, there is a new increasing group of patients with HPV-positive TSCC and BOTSCC with good clinical outcome, where options for better-tailored therapy are needed. For prevention, it would be of benefit to vaccinate both girls and boys against HPV16 infection. For potential future screening the ways to do so need optimizing

Reduced Expression of the Antigen Processing Machinery Components TAP2, LMP2, and LMP7 in Tonsillar and Base of Tongue Cancer and Implications for Clinical Outcome

OBJECTIVES: Patients with human papillomavirus (HPV)–positive tonsillar squamous cell carcinoma (TSCC) and base of tongue squamous cell carcinoma (BOTSCC) have a better clinical outcome than those with corresponding HPV-negative tumors. Moreover, there is a strong positive correlation between absent/low as opposed to strong HLA class I expression and favorable clinical outcome for HPV-positive tumors, while the reverse applies to HPV-negative tumors. The expression of the antigen processing machinery (APM) components TAP1, TAP2, LMP2, and LMP7 in these tumors in relation to HPV status, HLA class I expression, each other, and clinical outcome was therefore investigated. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded TSCC and BOTSCC, derived from 151 patients and previously analyzed for HPV DNA, HLA class I, and LMP10 expression were stained by immunohistochemistry for TAP1, TAP2, LMP2, and LMP7. RESULTS: Absent/low TAP2, LMP2, and LMP7 expression, similar to HLA class I and LMP10, was common in TSCC and BOTSCC, irrespective of HPV status. Expression of TAP1 and TAP2 was correlated, as was LMP2 to LMP7. LMP2 and LMP7 expression was also associated to HLA class I expression. Moreover, absence of LMP7 was linked to increased disease-free survival in both HPV-positive and HPV-negative cases. CONCLUSION: Reduced expression of TAP2, LMP2, and LMP7 was frequent in TSCC and BOTSCC and their expression as well as that of TAP1 was often interrelated. Furthermore, low LMP7 expression correlated to better clinical outcome and may, together with HPV status, potentially be used for prediction of treatment response

Correlation of LMP10 expression and clinical outcome in Human Papillomavirus (HPV) positive and HPV-Negative tonsillar and base of tongue cancer.

To examine LMP10 expression and its possible impact on clinical outcome in human papillomavirus (HPV) positive and HPV-negative tonsillar and base of tongue squamous cell carcinoma (TSCC and BOTSCC).Outcome is better in HPV-positive TSCC and BOTSCC compared to matching HPV-negative tumours, with roughly 80% vs. 40% 5-year disease free survival (DFS) with less aggressive treatment than today's chemoradiotherapy. Since current treatment often results in harmful side effects, less intensive therapy, with sustained patient survival would be an attractive alternative. However, other markers together with HPV status are necessary to select patients and for this purpose LMP10 expression is investigated here in parallel to HPV status and clinical outcome.From 385 patients diagnosed between 2000 and 2007 at the Karolinska University Hospital, 278 formalin fixed paraffin embedded TSCC and BOTSCC biopsies, with known HPV DNA status, were tested for LMP10 nuclear and cytoplasmic expression (fraction of positive cells and staining intensity). The data was then correlated to clinical outcome.An absent/low compared to a moderate/high LMP10 nuclear fraction of positive cells was correlated to a better 3-year DFS in the HPV-positive group of patients (log-rank p = 0.005), but not in the HPV-negative group. In the HPV-negative group of patients, in contrast to the HPV-positive group, moderate/high LMP10 cytoplasmic fraction and weak/moderate/high LMP10 cytoplasmic intensity correlated to a better 3-year DFS (p = 0.003 and p = 0.001) and 3-year overall survival (p = 0.001 and 0.009).LMP10 nuclear expression in the HPV-positive group and LMP10 cytoplasmic expression in the HPV-negative group of patients correlated to better clinical outcome

Human papillomavirus is a favourable prognostic factor in cancer of unknown primary in the head and neck region and in hypopharyngeal cancer

Human papillomavirus (HPV), in addition to smoking and alcohol, is a cause of oropharyngeal squamous cell carcinoma (OPSCC), particularly of the tonsils and base of the tongue (TSCC and BOTSCC, respectively). Moreover, HPV-positive TSCC and BOTSCC are associated with a better outcome compared with their HPV-negative counterparts (80 vs. 40% 3-year disease-free survival rate, respectively) and their incidence has increased in several countries. Recently, accumulating evidence of HPV in a considerable proportion of cancers of unknown primary (CUP) in the head and neck region and in a small proportion of hypopharyngeal SCCs has been reported. Furthermore, HPV-positive tumours, particularly cases with HPV DNA positivity in combination with overexpression of p16, also tend to have a better clinical outcome compared with that of the corresponding HPV-negative tumours. This finding is particularly prominent in HPV-positive CUPs of the head and neck region, where the primary tumour likely originates from the oropharynx. Thus, the determination of HPV status and p16 expression may be of value for the diagnosis and treatment of CUP of the head and neck region and may also be of value for hypopharyngeal cancers in the future. However, for hypopharyngeal cancer as well as other non-OPSCCs, additional studies per subsite on the effect of HPV status on survival are required

Absent/weak CD44 intensity and positive human papillomavirus (HPV) status in oropharyngeal squamous cell carcinoma indicates a very high survival

Patients with human papillomavirus DNA positive (HPVDNA+) oropharyngeal squamous cell carcinoma (OSCC) have better clinical outcome than those with HPV DNA negative (HPVDNA-) OSCC upon intensive oncological treatment. All HPVDNA+ OSCC patients may not require intensive treatment, however, but before potentially deintensifying treatment, additional predictive markers are needed. Here, we examined HPV, p16(INK4a), and CD44 in OSCC in correlation to clinical outcome. Pretreatment tumors from 290 OSCC patients, the majority not receiving chemotherapy, were analyzed for HPV DNA by Luminex and for p16(INK4a) and CD44 by immunohistochemistry. 225/290 (78%) tumors were HPVDNA+ and 211/290 (73%) overexpressed p16(INK4a), which correlated to presence of HPV (P < 0.0001). Presence of HPV DNA, absent/weak CD44 intensity staining correlated to favorable 3-year disease-free survival (DFS) and overall survival (OS) by univariate and multivariate analysis, and likewise for p16(INK4a) by univariate analysis. Upon stratification for HPV, HPVDNA+ OSCC with absent/weak CD44 intensity presented the significantly best 3-year DFS and OS, with >95% 3-year DFS and OS. Furthermore, in HPVDNA+ OSCC, p16(INK4a)+ overexpression correlated to a favorable 3-year OS. In conclusion, patients with HPVDNA+ and absent/weak CD44 intensity OSCC presented the best survival and this marker combination could possibly be used for selecting patients for tailored deintensified treatment in prospective clinical trials. Absence of/weak CD44 or presence of human papillomavirus (HPV) DNA was shown as a favorable prognostic factors in tonsillar and tongue base cancer. Moreover, patients with the combination of absence of/weak CD44 and presence of HPV DNA presented a very favorable outcome. Therefore, we suggest that this marker combination could potentially be used to single out patients with a high survival that could benefit from a de-escalated oncological treatment