Investigator

Andreas M. Kaufmann

Charit Universittsmedizin Berlin

AMKAndreas M. Kaufma…
Papers(6)
Linking Microbiome Di…Prevalence of human p…Blockade of ALDH in C…Female health-care pr…Reasons for Not Atten…The Catastrophic HPV/…
Collaborators(10)
Eva Johanna Kantelhar…Anna-Lisa BehnkeAnn H. KloppAnuja JhingranBrhanu TekaCara L HaymakerDawit WorkuEdedia FirdawokeKyoko Yoshida-CourtLauren E. Colbert
Institutions(4)
Charit Universittsmed…Martin-Luther-Univers…The University Of Tex…Addis Ababa University

Papers

Linking Microbiome Diversity and Immune Profiles in Ethiopian Patients With Cervical Cancer

PURPOSE This study investigates the interplay between T-cell receptor (TCR) immune characteristics and microbiome profiles to explore the relationship between immune diversity and microbial composition in cervical samples from Ethiopia. METHODS Cervical specimens were collected from patients at Tikur Anbessa Specialized Hospital in Addis Ababa, and rural Butajira, south-central Ethiopia. Patient data, including age, human papillomavirus status, pathology, and TCR immune characteristics, were analyzed with a focus on the interactions between TCR profiles and microbiome compositions in malignant samples. RESULTS Three distinct TCR profiles were identified: Group 1 (TCR active) exhibited features of active immune engagement, including high diversity, clonal expansion, and repertoire richness. Group 2 (TCR restricted) showed reduced TCR diversity and expansion, suggesting a restricted repertoire. Group 3 (TCR balanced) had moderate diversity and clonal activity. TCR repertoire groups were linked with microbial diversity, with Group 1 (TCR active) showing the highest number of microbes (high operational taxonomic units and microbial diversity). Maximum TCR clonal expansion positivity associated with microbial richness, while Group 3 (TCR balanced) was linked to reduced microbial alpha diversity. Taxonomic analysis revealed specific organisms enriched in TCR repertoire group. CONCLUSION Variations in TCR profiles are linked to distinct microbial environments in cervical cancer with greater microbial richness in patients with greater maximum productive frequency. These findings underscore the interplay between TCR diversity, microbiome composition, and malignancy, offering insights into the potential implications for microbiome-targeted therapies and prognostic biomarkers in cervical cancer.

Prevalence of human papillomavirus detection in ovarian cancer: a meta-analysis

AbstractWe conducted a meta-analysis of published data to update and estimate the prevalence of HPV in ovarian cancer. A comprehensive literature search was performed according to the PRISMA guidelines. Eligible articles published from 1989 until 2020 by searching Web of Sciences, Pubmed, Embase, and the Cochrane Library Central databases were gathered. A pooled estimation of HPV prevalence with a 95% confidence interval (CI) was calculated based on a random effect model. Quantitative assessment of heterogeneity was explored using Cochrane test and I2. Additionally, publication bias, sensitivity, meta-regression, and subgroup analyses were also performed. Twenty-nine studies involving 2280 patients with ovarian cancer were included. The statistical heterogeneity was high (I2 = 88%, P<0.0001). The pooled prevalence of HPV in ovarian cancer cases was 15.9% (95% CI, 11–22). In subgroup analyses, the highest prevalence of HPV was reported by studies from Asia (30.9%; 95% CI, 20–44) and Eastern Europe (29.3%; 95% CI, 4.4–78). Furthermore, the most frequently detected HPV genotype was HPV16 (54%; 95% CI, 27.9–55), followed by HPV18 (23.2%; 95% CI, 18.8–28.2). Our meta-analysis suggests a great difference in the prevalence of HPV detected in ovarian cancer by different studies, which is not seen in strongly HPV-associated cancers such as cervical cancer. However, the prevalence varied markedly by geographic region. Considering the substantial heterogeneity found, more studies with control groups and precise assays measuring HPV mRNA expression are needed to further evaluate the link and causative aetiology between HPV and ovarian cancer.

Blockade of ALDH in Cisplatin-Resistant Ovarian Cancer Stem Cells In Vitro Synergistically Enhances Chemotherapy-Induced Cell Death

Epithelial ovarian cancer (EOC) is the leading cause of gynecological cancer-related death. The high mortality and morbidity associated with EOC are mostly due to late diagnosis and chemotherapy drug resistance. Currently, the standard first-line chemotherapy regimen is systemic administration of platinum-based chemotherapy combined with a taxane. A major problem besides cisplatin resistance (occurring in nearly one-third of patients) is the greater toxicity of the drug combinations. A synergistic treatment with drug supporting activity could maximize the cytotoxic effects of chemotherapeutic agents on tumor cells while decreasing the dosage of each drug to potentially reduce toxicity. The ALDH-blocking agent Disulfiram (DSF), a clinically approved drug used for alcoholism treatment, has displayed promising anti-cancer activity. We previously described that blocking ALDH activity enhances the induction of apoptosis, especially in ovarian cancer stem cells treated with chemotherapeutic agents. In this study, we further investigated the synergistic effect of DSF in combination with cytotoxic chemotherapeutic drugs. The concentration of each chemotherapeutic agent could be significantly reduced with sustained efficacy on tumor cell apoptosis in cell lines in vitro (Dose-Reduction Index at IC50 from 1 to 50). Moreover, the potential chemo-sensitizing effects of DSF on ALDH-associated cisplatin-resistant ovarian cancer stem cells were also investigated and shown that in contrast to its high resistance to cisplatin, the cisplatin-resistant cells remain very sensitive to DSF-induced cytotoxicity (apoptosis and necrosis: cisplatin-resistant cells vs. parental cells: 60.4% vs. 20.5%). In combination with DSF and cisplatin, relatively more apoptosis and necrosis were induced in cisplatin-resistant cells than in their parental cells (apoptosis and necrosis: cisplatin-resistant cells vs. parental cells: 81.5% vs. 50.1%). A transcriptome analysis identified that ALDH was mainly enriched in the cancer-associated fibroblasts and showed that ALDH plays roles in responding to oxidative stress, metabolisms, and energy transition in the ALDH-associated cisplatin-resistant ovarian cancer stem cells. In conclusion, our data demonstrate a key role of ALDH-associated cisplatin-resistant cancer stem cells and identifies DSF as a potential adjuvant for a rational protocol design by computational quantitative assessment in vitro on ovarian cancer cell lines. Our work contributes to resolving the ALDH-associated cisplatin resistance and provides a resource for the development of novel chemotherapeutic regimens.

Female health-care providers’ advocacy of self-sampling after participating in a workplace program for cervical cancer screening in Ghana: a mixed-methods study

Cervical cancer is the second most common cancer among Ghanaian women and screening coverage is low. ACCESSING is a cross-sectional study investigating human papillomavirus (HPV) prevalence via self-sampling in rural communities of the North Tongu district in Ghana. Female health-care providers (HCPs) were invited to self-collect a cervicovaginal sample with a commercial sampler in order to acquaint themselves with the sampling method. This study set out to explore female HCPs' perceptions, advocacy for, and implications of self-sampling with the aim of enhancing self-sampling acceptability in the targeted screening population. A mixed-methods approach was used, consisting of (a) a survey among 52 female HCPs working in a district hospital and (b) 10 one-to-one semi-structured interviews with purposefully sampled HCPs. The quantitative analysis of the survey (n = 52) showed that, among HCPs who took the sample themselves (50/52), all found it 'Easy' or 'Very Easy' and felt 'Very Comfortable' or 'Comfortable'. 82.7% indicated that they would undertake screening more often, and 98.1% indicated they would prefer self-sampling, if cervical cancer risk is as reliably determined as by clinician-directed cytobrush sampling. All interview participants (n = 10) indicated that they appreciated the program and would recommend the screening to their patients and/or family members and neighbours. Common reasons for preferring self-sampling were less (anticipated) pain compared to speculum examination and more privacy. Self-sampling for cervical cancer screening is highly acceptable to female HCPs. Setting up a workplace screening program that entails the option of self-sampling could create greater awareness and positive attitudes among HCPs to educating their patients, families, and neighbours on cervical cancer risks and motivate HCPs to advocate for women's participation in screening.

Reasons for Not Attending Cervical Cancer Screening and Associated Factors in Rural Ethiopia

Abstract Social, economic, and cultural factors have been associated with the level of participation in cervical cancer screening programs. This study identified factors associated with nonparticipation in cervical cancer screening, as well as reasons for not attending, in the context of a population-based, cluster-randomized trial in Ethiopia. A total of 2,356 women aged 30 to 49 years in 22 clusters were invited to receive one of two screening approaches, namely human papillomavirus (HPV) self-sampling or visual inspection with acetic acid (VIA). Participants and nonparticipants were analyzed according to their sociodemographic and economic characteristics. Reasons were determined for the refusal of women to participate in either screening method. More women in the VIA arm compared to the HPV arm declined participation in the screening [adjusted OR (AOR) 3.5; 95% confidence interval (CI), 2.6–4.8]. Women who declined attending screening were more often living in rural areas (AOR = 2.0; 95% CI, 1.1–3.5) and were engaged in informal occupations (AOR = 1.6; 95% CI, 1.1–2.4). The majority of nonattendants perceived themselves to be at no risk of cervical cancer (83.1%). The main reasons given for not attending screening for both screening approaches were lack of time to attend screening, self-assertion of being healthy, and fear of screening. We found that perceived time constraints and the perception of being at no risk of getting the disease were the most important barriers to screening. Living in rural settings and informal occupation were also associated with lower participation. Offering a swift and convenient screening service could increase the participation of women in cervical cancer screening at the community level.

The Catastrophic HPV/HIV Dual Viral Oncogenomics in Concert with Dysregulated Alternative Splicing in Cervical Cancer

Cervical cancer is a public health problem and has devastating effects in low-to-middle-income countries (LTMICs) such as the sub-Saharan African (SSA) countries. Infection by the human papillomavirus (HPV) is the main cause of cervical cancer. HIV positive women have higher HPV prevalence and cervical cancer incidence than their HIV negative counterparts do. Concurrent HPV/HIV infection is catastrophic, particularly to African women due to the high prevalence of HIV infections. Although various studies show a relationship between HPV, HIV and cervical cancer, there is still a gap in the knowledge concerning the precise nature of this tripartite association. Firstly, most studies show the relationship between HPV and cervical cancer at genomic and epigenetic levels, while the transcriptomic landscape of this relationship remains to be elucidated. Even though many studies have shown HPV/HIV dual viral pathogenesis, the dual molecular oncoviral effects on the development of cervical cancer remains largely uncertain. Furthermore, the effect of highly active antiretroviral therapy (HAART) on the cellular splicing machinery is unclear. Emerging evidence indicates the vital role played by host splicing events in both HPV and HIV infection in the development and progression to cervical cancer. Therefore, decoding the transcriptome landscape of this tripartite relationship holds promising therapeutic potential. This review will focus on the link between cellular splicing machinery, HPV, HIV infection and the aberrant alternative splicing events that take place in HIV/HPV-associated cervical cancer. Finally, we will investigate how these aberrant splicing events can be targeted for the development of new therapeutic strategies against HPV/HIV-associated cervical cancer.

6Papers
20Collaborators