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| 2. |
- Indukuri, Rajitha
(författare)
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Estrogen receptor beta transcriptional regulation: A potential mechanism for colon cancer prevention
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colorectal cancer (CRC) is the third leading cause of death from cancer in both men andwomen in the Western world. Improved screening efforts, surveillance, and treatment havereduced CRC mortality in older patients. However, the incidence is increasing in young adults,even in the absence of CRC family history. This may indicate an influence of increasingobesity, changed dietary patterns, and lifestyle factors. The progression of CRC is a multistepprocedure that takes 10-15 years, thus offering a time to implement preventative measures andearly detection. There is a critical need to develop more effective preventive therapies due tothe risks posed by current prevention therapies. The best CRC prophylactic agent should beboth safe and suitable to use for a long time (1).In preclinical studies, estrogen has been shown to protect from CRC, and substantial evidencesuggests it is through estrogen receptor beta (ERβ). Natural ERβ selective agonists have beentested in phase II clinical trials to treat menopause symptoms and proven to be safe and welltolerated with no side effects (2, 3). Thus, selective activation of ERβ with selective agonists,which do not activate estrogen receptor alpha (ERα), is a potential clinical approach inpreventing adenomatous polyps progression into CRC. However, the mechanism of thesebeneficial ERβ effects is not well understood, and there is a significant knowledge gap in thisarea.The overall aim of this thesis was to identify the mechanistic background of the intestinal ERβmediated antitumorigenic effects in the colon and further to explore ERβ as a preventativeapproach in CRC. One specific aim was to determine whether ERβ present specifically in colonepithelium is responsible for protecting from CRC, which is addressed in Paper I. Tounderstand the impact of ERβ in protecting from colitis-associated CRC (CA-CRC), we haveinduced colitis in intestinal-specific ERβ knockout mice of both sexes. The loss of intestinalERβ aggravated CA-CRC in a sex-dependent manner. The incidence of tumors increased inmales, while in females, the size of the tumors was enhanced. We identified that ERβ attenuatestumor necrosis factor alpha (TNFα) induced epithelial cell damage and modulates theregulation of key nuclear factor-κB (NFκB) members. As a direct consequence, ERβ was foundto reduce inflammation and to control intestinal crypt cell proliferation.Another aim was to explore transcriptional regulation by ERβ through mapping of chromatinbinding sites and interaction with NFκB, which is studied in Paper II and IV. Commonly usedERβ antibodies have been shown to be unspecific towards ERβ; this study used a validatedERβ antibody to map genome-wide ERβ binding sites in colon cancer cells. We observed thatthe presence of ERβ also modulated the regulatory chromatin mark H3K27AC in potentialenhancers of transcriptional regulation, Wnt signaling, and cell proliferation. Further, motifanalysis indicated a novel ERβ colon-specific cross-talk with TCF, and KLF motifs supporteda interaction between β-catenin/TCF and ERβ. We found that ERβ binds and regulates severalimportant tumor suppressors and oncogenes in CRC cells, such as CST5 and LRP6, consistentwith its proposed antitumorigenic activity. We also revealed the p65 cistrome in CRC cell lines and showed that ERβ alters the p65 chromatin binding in a cell-type-dependent manner. Wefound that ERβ chromatin binding sites were enriched among circadian clock genes and alsothat ERβ modulates p65 binding to core clock genes in CRC cells, indicating potential crosstalk between ERβ and circadian clock gene regulation.The final aim was to investigate the impact of ERβ, and estrogen signaling in high-fat diet(HFD) induced inflammation in colon, explored in paper III. We fed mice with an HFD for 13weeks and treated them with estrogenic ligands for the last three weeks prior to sacrifice. Thecolon transcriptome showed predominant sex differences, and selective activation of ERβreduced macrophage infiltration and epithelial cell proliferation induced by HFD. Wedemonstrated that ERβ opposes HFD-induced dysregulation of core circadian clock genes invivo, further strengthening the role of ERβ in circadian rhythm.Taken together, these results highlight the chemopreventive potential of ERβ in CRC in bothsexes. The identified cross-talk with TNFα/NFκB pathway, Wnt signaling, regulating genesinvolved circadian clock, and tumorigenesis reflected ERβ protection/antitumor activityagainst CRC progression and development (as illustrated in Figure 1).
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| 3. |
- Hakim Jaffer Ali, Mohammed, et al.
(författare)
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Benchmarking virus concentration methods for quantification of SARS-CoV-2 in raw wastewater
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 755
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Tidskriftsartikel (refereegranskat)abstract
- Wastewater-based epidemiology offers a cost-effective alternative to testing large populations for SARS-CoV-2 virus, and may potentially be used as an early warning system for SARS-CoV-2 pandemic spread. However, viruses are highly diluted in wastewater, and a validated method for their concentration and further processing, and suitable reference viruses, are the main needs to be established for reliable SARS-CoV-2 municipal wastewater detection. For this purpose, we collected wastewater from two European cities during the Covid-19 pandemic and evaluated the sensitivity of RT-qPCR detection of viral RNA after four concentration methods (two variants of ultrafiltration-based method and two adsorption and extraction-based methods). Further, we evaluated one external (bovine corona virus) and one internal (pepper mild mottle virus) reference virus. We found a consistently higher recovery of spiked virus using the modified ultrafiltration-based method. This method also had a significantly higher efficiency (p-value <0.01) for wastewater SARS-CoV-2 detection. The ultracentrifugation method was the only method that detected SARS-CoV-2 in the wastewater of both cities. The pepper mild mottle virus was found to function as a potentially suitable internal reference standard.
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- Hases, Linnea, et al.
(författare)
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The Importance of Sex in the Discovery of Colorectal Cancer Prognostic Biomarkers
- 2021
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1661-6596 .- 1422-0067. ; 22:3
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is the third leading cause of cancer deaths. Advances within bioinformatics, such as machine learning, can improve biomarker discovery and ultimately improve CRC survival rates. There are clear sex differences in CRC characteristics, but the impact of sex has not been considered with regards to CRC biomarkers. Our aim here was to investigate sex differences in the transcriptome of a normal colon and CRC, and between paired normal and tumor tissue. Next, we attempted to identify CRC diagnostic and prognostic biomarkers and investigate if they are sex-specific. We collected paired normal and tumor tissue, performed RNA-seq, and applied feature selection in combination with machine learning to identify the top CRC diagnostic biomarkers. We used The Cancer Genome Atlas (TCGA) data to identify sex-specific CRC diagnostic biomarkers and performed an overall survival analysis to identify sex-specific prognostic biomarkers. We found transcriptomic sex differences in both the normal colon tissue and in CRC. Forty-four of the top-ranked biomarkers were sex-specific and 20 biomarkers showed a sex-specific prognostic value. Our data show the importance of sex in the discovery of CRC biomarkers. We propose 20 sex-specific CRC prognostic biomarkers, including ESM1, GUCA2A, and VWA2 for males and CLDN1 and FUT1 for females.
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| 5. |
- Indukuri, Rajitha, et al.
(författare)
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Estrogen Receptor Beta Influences the Inflammatory p65 Cistrome in Colon Cancer Cells
- 2021
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Ingår i: Frontiers in Endocrinology. - : FRONTIERS. - 1664-2392. ; 12, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Inflammation is a primary component of both initiation and promotion of colorectal cancer (CRC). Cytokines secreted by macrophages, including tumor necrosis factor alpha (TNFα), activates the pro-survival transcription factor complex NFκB. The precise mechanism of NFκB in CRC is not well studied, but we recently reported the genome-wide transcriptional impact of TNFα in two CRC cell lines. Further, estrogen signaling influences inflammation in a complex manner and suppresses CRC development. CRC protective effects of estrogen have been shown to be mediated by estrogen receptor beta (ERβ, ESR2), which also impacts inflammatory signaling of the colon. However, whether ERβ impacts the chromatin interaction (cistrome) of the main NFκB subunit p65 (RELA) is not known. We used p65 chromatin immunoprecipitation followed by sequencing (ChIP-Seq) in two different CRC cell lines, HT29 and SW480, with and without expression of ERβ. We here present the p65 colon cistrome of these two CRC cell lines. We identify that RELA and AP1 motifs are predominant in both cell lines, and additionally describe both common and cell line-specific p65 binding sites and correlate these to transcriptional changes related to inflammation, migration, apoptosis and circadian rhythm. Further, we determine that ERβ opposes a major fraction of p65 chromatin binding in HT29 cells, but enhances p65 binding in SW480 cells, thereby impacting the p65 cistrome differently in the two cell lines. However, the biological functions of the regulated genes appear to have similar roles in both cell lines. To our knowledge, this is the first time the p65 CRC cistrome is compared between different cell lines and the first time an influence by ERβ on the p65 cistrome is investigated. Our work provides a mechanistic foundation for a better understanding of how estrogen influences inflammatory signaling through NFκB in CRC cells.
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| 6. |
- Indukuri, Rajitha, et al.
(författare)
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Genome-wide estrogen receptor β chromatin binding in humancolon cancer cells reveals its tumor suppressor activity
- 2021
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215.
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is the third leading cause of cancer death in the western world. In women, menopausal hormone therapy has been shown to reduce CRC incidence by 20%. Studies demonstrate that estrogen activating estrogen receptor beta (ERβ) protects against CRC. ERβ is a nuclear receptor that regulates gene expression through interactions with the chromatin. This molecular mechanism is, however, not well characterized in colon. Here, we present for the first time, the cistrome of ERβ in different colon cancer cell lines. We use cell lines engineered to express ERβ, optimize and validate an ERβ antibody for chromatin-immunoprecipitation (ChIP), and perform ChIP-Seq. We identify key binding motifs, including ERE, AP-1, and TCF sites, and we determine enrichment of binding to cis-regulatory chromatin sites of genes involved in tumor development, cell migration, cell adhesion, apoptosis, and Wnt signaling pathways. We compare the corresponding cistromes of colon and breast cancer and find that they are conserved for about a third of genes, including GREB1, but that ERβ tethering to TCF and KLF family motifs is characteristic for colon. We exemplify upregulation of putative CRC tumor suppressor gene CST5 where ERβ in colon cells binds to cis-regulatory regions nearby (−351 bp) the transcriptional start site. Our work provides a foundation for understanding the mechanism of action of ERβ in CRC prevention.
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| 7. |
- Liu, Qing, et al.
(författare)
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Menopausal hormone therapies and risk of colorectal cancer : a Swedish matched-cohort study.
- 2021
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Ingår i: Alimentary Pharmacology and Therapeutics. - : John Wiley & Sons. - 0269-2813 .- 1365-2036. ; 53:11, s. 1216-1225
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Menopausal hormone therapy (MHT) has been associated with various malignancies.AIMS: To investigate the association of various MHT regimens with the risk of colorectal cancer (CRC).METHODS: All MHT ever-users (n = 290 186) were included through the Swedish Prescribed Drug Registry, with a 1:3 group-level matching to non-users. Ever-users were defined as women who received ≥1 dispensed prescription of systemic MHT during 2005-2012 in Sweden. All CRC cases after drug initiation were extracted from the Swedish Cancer Registry. The association was assessed by multivariable conditional logistic and Cox regression models, presented as odds ratios (ORs) or hazard ratios (HRs) with 95% confidence intervals (CIs) considering different regimens, duration and age at treatment initiation.RESULTS: Compared with non-users, MHT users had an overall reduced odds for colon (OR = 0.67, 95% CI 0.63-0.72) and rectal adenocarcinoma (OR = 0.66, 95% CI 0.60-0.73), especially among women aged 40-60 years. Current users of oestrogen-only preparations (E-MHT) showed a reduced odds (colon OR = 0.73, 95% CI 0.65-0.82; rectal OR = 0.76, 95% CI 0.64-0.90) compared to non-users, particularly with oestradiol and oestriol. Past E-MHT use showed stronger odds reductions (colon OR = 0.49, 95% CI 0.43-0.56; rectal OR = 0.36, 95% CI 0.28-0.45). Current use of oestrogen combined progestin therapy (EP-MHT) indicated a less prominent odds reduction (colon adenocarcinoma OR 0.62, 95% CI 0.54-0.72; rectal adenocarcinoma OR = 0.60, 95% CI 0.49-0.74) than past users. Tibolone showed an increased risk of left-sided colorectal adenocarcinoma. Oral and cutaneous MHT usage showed similar patterns.CONCLUSIONS: MHT use may decrease colorectal adenocarcinoma risk, for both E-MHT and EP-MHT, and especially in past users.
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| 8. |
- Song, Dandan, et al.
(författare)
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Blocking Fra-1 sensitizes triple-negative breast cancer to PARP inhibitor
- 2021
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Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835 .- 1872-7980. ; 506, s. 23-34
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Tidskriftsartikel (refereegranskat)abstract
- The AP-1 member Fra-1 is overexpressed in TNBC and plays crucial roles in tumor progression and treatment resistance. In a previous large-scale screen, we identified PARP1 to be among 118 proteins that interact with endogenous chromatin-bound Fra-1 in TNBC cells. PARP1 inhibitor (olaparib) is currently in clinical use for treatment of BRCA-mutated TNBC breast cancer. Here, we demonstrate that the Fra-1-PARP1 interaction impacts the efficacy of olaparib treatment. We show that PARP1 interacts with and downregulates Fra-1, thereby reducing AP-1 transcriptional activity. Olaparib treatment, or silencing of PARP1, consequently, increases Fra-1 levels and enhances its transcriptional activity. Increased Fra-1 can have adverse effect, including treatment resistance. We also found that a large fraction of PARP1-regulated genes was dependent on Fra-1. We show that by inhibiting Fra-1/AP-1, non-BRCA-mutated TNBC cells can become sensitized to olaparib treatment. We identify that high PARP1 expression is indicative of a poor clinical outcome in breast cancer patients overall (P = 0.01), but not for HER-2 positive patients. In conclusion, by exploring the functionality of the Fra-1 and PARP1 interaction, we propose that targeting Fra-1 could serve as a combinatory therapeutic approach to improve olaparib treatment outcome for TNBC patients.
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