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1.
Cancer Lett ; 584: 216608, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38199587

ABSTRACT

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.


Subject(s)
Antineoplastic Agents , Breast Neoplasms , Lung Neoplasms , Female , Humans , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , BRCA1 Protein/genetics , BRCA1 Protein/metabolism , BRCA2 Protein/genetics , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Line, Tumor , DNA , Genes, p53 , Lung Neoplasms/genetics , Mutation , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Poly(ADP-ribose) Polymerases/metabolism , Temozolomide/pharmacology , Temozolomide/therapeutic use , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
2.
bioRxiv ; 2023 Jun 22.
Article in English | MEDLINE | ID: mdl-38076873

ABSTRACT

Poly (ADP-ribose) polymerase inhibitors (PARPi) are used for patients with BRCA1/2 mutations, but patients with other mutations may benefit from PARPi treatment. Another mutation that is present in more cancers than BRCA1/2 is mutation to the TP53 gene. In 2D breast cancer cell lines, mutant p53 (mtp53) proteins tightly associate with replicating DNA and Poly (ADP-ribose) polymerase (PARP) protein. Combination drug treatment with the alkylating agent temozolomide and the PARPi talazoparib kills mtp53 expressing 2D grown breast cancer cell lines. We evaluated the sensitivity to the combination of temozolomide plus PARPi talazoparib treatment to breast and lung cancer patient-derived tumor organoids (PDTOs). The combination of the two drugs was synergistic for a cytotoxic response in PDTOs with mtp53 but not for PDTOs with wtp53. The combination of talazoparib and temozolomide induced more DNA double-strand breaks in mtp53 expressing organoids than in wild-type p53 expressing organoids as shown by increased γ-H2AX protein expression. Moreover, breast cancer tissue microarrays (TMAs) showed a positive correlation between stable p53 and high PARP1 expression in sub-groups of breast cancers, which may indicate sub-classes of breast cancers sensitive to PARPi therapy. These results suggest that mtp53 could be a biomarker to predict response to the combination of PARPi talazoparib-temozolomide treatment.

3.
Cancer Discov ; 12(11): 2530-2551, 2022 11 02.
Article in English | MEDLINE | ID: mdl-36121736

ABSTRACT

Women of sub-Saharan African descent have disproportionately higher incidence of triple-negative breast cancer (TNBC) and TNBC-specific mortality across all populations. Population studies show racial differences in TNBC biology, including higher prevalence of basal-like and quadruple-negative subtypes in African Americans (AA). However, previous investigations relied on self-reported race (SRR) of primarily U.S. populations. Due to heterogeneous genetic admixture and biological consequences of social determinants, the true association of African ancestry with TNBC biology is unclear. To address this, we conducted RNA sequencing on an international cohort of AAs, as well as West and East Africans with TNBC. Using comprehensive genetic ancestry estimation in this African-enriched cohort, we found expression of 613 genes associated with African ancestry and 2,000+ associated with regional African ancestry. A subset of African-associated genes also showed differences in normal breast tissue. Pathway enrichment and deconvolution of tumor cellular composition revealed that tumor-associated immunologic profiles are distinct in patients of African descent. SIGNIFICANCE: Our comprehensive ancestry quantification process revealed that ancestry-associated gene expression profiles in TNBC include population-level distinctions in immunologic landscapes. These differences may explain some differences in race-group clinical outcomes. This study shows the first definitive link between African ancestry and the TNBC immunologic landscape, from an African-enriched international multiethnic cohort. See related commentary by Hamilton et al., p. 2496. This article is highlighted in the In This Issue feature, p. 2483.


Subject(s)
Triple Negative Breast Neoplasms , Humans , Female , Triple Negative Breast Neoplasms/genetics , Transcriptome , Black or African American/genetics , Biology
4.
Sci Rep ; 11(1): 9247, 2021 04 29.
Article in English | MEDLINE | ID: mdl-33927264

ABSTRACT

Large-scale efforts to identify breast cancer (BC) risk alleles have historically taken place among women of European ancestry. Recently, there are new efforts to verify if these alleles increase risk in African American (AA) women as well. We investigated the effect of previously reported AA breast cancer and triple-negative breast cancer (TNBC) risk alleles in our African-enriched International Center for the Study of Breast Cancer Subtypes (ICSBCS) cohort. Using case-control, case-series and race-nested approaches, we report that the Duffy-null allele (rs2814778) is associated with TNBC risk (OR = 3.814, p = 0.001), specifically among AA individuals, after adjusting for self-indicated race and west African ancestry (OR = 3.368, p = 0.007). We have also validated the protective effect of the minor allele of the ANKLE1 missense variant rs2363956 among AA for TNBC (OR = 0.420, p = 0.005). Our results suggest that an ancestry-specific Duffy-null allele and differential prevalence of a polymorphic gene variant of ANKLE1 may play a role in TNBC breast cancer outcomes. These findings present opportunities for therapeutic potential and future studies to address race-specific differences in TNBC risk and disease outcome.


Subject(s)
Black People/genetics , Duffy Blood-Group System/genetics , Endonucleases/genetics , Receptors, Cell Surface/genetics , Triple Negative Breast Neoplasms/genetics , White People/genetics , Alleles , Biomarkers, Tumor/genetics , Case-Control Studies , Cohort Studies , Female , Genotype , Humans , Internationality , Middle Aged , Risk Factors , Triple Negative Breast Neoplasms/epidemiology , Triple Negative Breast Neoplasms/pathology
5.
STAR Protoc ; 2(1): 100225, 2021 03 19.
Article in English | MEDLINE | ID: mdl-33786456

ABSTRACT

We developed a modified protocol, based on differential ultracentrifugation (dUC), to isolate extracellular vesicles and particles (specifically exomeres) (EVPs) from various human and murine sources, including cell lines, surgically resected tumors and adjacent tissues, and bodily fluids, such as blood, lymphatic fluid, and bile. The diversity of these samples requires robust and highly reproducible protocols and refined isolation technology, such as asymmetric-flow field-flow fractionation (AF4). Our isolation protocol allows for preparation of EVPs for various downstream applications, including proteomic profiling. For complete details on the use and execution of this protocol, please refer to Hoshino et al. (2020).


Subject(s)
Body Fluids/chemistry , Centrifugation, Density Gradient , Extracellular Vesicles/chemistry , Fractionation, Field Flow , Proteomics , Animals , Cell Line , Humans , Mice
6.
Cell ; 182(4): 1044-1061.e18, 2020 08 20.
Article in English | MEDLINE | ID: mdl-32795414

ABSTRACT

There is an unmet clinical need for improved tissue and liquid biopsy tools for cancer detection. We investigated the proteomic profile of extracellular vesicles and particles (EVPs) in 426 human samples from tissue explants (TEs), plasma, and other bodily fluids. Among traditional exosome markers, CD9, HSPA8, ALIX, and HSP90AB1 represent pan-EVP markers, while ACTB, MSN, and RAP1B are novel pan-EVP markers. To confirm that EVPs are ideal diagnostic tools, we analyzed proteomes of TE- (n = 151) and plasma-derived (n = 120) EVPs. Comparison of TE EVPs identified proteins (e.g., VCAN, TNC, and THBS2) that distinguish tumors from normal tissues with 90% sensitivity/94% specificity. Machine-learning classification of plasma-derived EVP cargo, including immunoglobulins, revealed 95% sensitivity/90% specificity in detecting cancer. Finally, we defined a panel of tumor-type-specific EVP proteins in TEs and plasma, which can classify tumors of unknown primary origin. Thus, EVP proteins can serve as reliable biomarkers for cancer detection and determining cancer type.


Subject(s)
Biomarkers, Tumor/metabolism , Extracellular Vesicles/metabolism , Neoplasms/diagnosis , Animals , Biomarkers, Tumor/blood , Cell Line , HSC70 Heat-Shock Proteins/metabolism , Humans , Machine Learning , Mice , Mice, Inbred C57BL , Microfilament Proteins/metabolism , Neoplasms/metabolism , Proteome/analysis , Proteome/metabolism , Proteomics/methods , Sensitivity and Specificity , Tetraspanin 29/metabolism , rap GTP-Binding Proteins/metabolism
7.
Am J Surg ; 219(4): 563-565, 2020 04.
Article in English | MEDLINE | ID: mdl-32008719

ABSTRACT

INTRODUCTION: Global health initiatives provide exciting opportunities for capacity-building in low- and middle-income countries but data regarding how African clinicians characterize the most effective partnerships are lacking. METHODS: We surveyed attendees at two "Breast Cancer in Africa" symposia sponsored through a surgeon-led global breast cancer research collaborative. Respondents ranked their preferences for needs from American global health partnerships. RESULTS: 399 African attendees responded (170 at the 2017 Ghana conference; 229 at the 2018 Ethiopia conference). Physicians comprised 41.1% of respondents; nurses 20.1% and medical students 27.6%. Ancillary hospital staff comprised the remaining 11.2%. Among clinicians, 75.7% ranked educational/training programs or donation of medical supplies as the highest-priority needs compared to only 20.4% ranking direct monetary support as the highest-priority need (P < 0.0001). CONCLUSIONS: Our survey study found that African clinicians prioritize training programs and donation of medical/hospital supplies above direct monetary support as their highest-value needs from global health initiatives.


Subject(s)
Breast Neoplasms , Capacity Building , Global Health , Needs Assessment , Africa , Biomedical Research , Congresses as Topic , Equipment and Supplies/supply & distribution , Female , Health Personnel/education , Humans , International Educational Exchange , Medical Oncology/education
8.
Ann Surg ; 270(3): 484-492, 2019 09.
Article in English | MEDLINE | ID: mdl-31356281

ABSTRACT

OBJECTIVE: To investigate subtype-specific risk of germline alleles associated with triple negative breast cancer (TNBC) in African ancestry populations. BACKGROUND: Breast cancer (BC) mortality is higher in African American (AA) compared to White American (WA) women; this disparity is partly explained by 2-fold higher TNBC incidence. METHODS: We used a surgically maintained biospecimen cohort of 2884 BC cases. Subsets of the total (760 AA; 962 WA; 910 West African/Ghanaian; 252 East African/Ethiopian) were analyzed for genotypes of candidate alleles. A subset of 417 healthy controls were also genotyped, to measure associations with overall BC risk and TNBC. RESULTS: TNBC frequency was highest in Ghanaian and AA cases (49% and 44% respectively; P < 0.0001) and lowest in Ethiopian and WA cases (17% and 24% respectively; P < 0.0001). TNBC cases had higher West African ancestry than non-TNBC (P < 0.0001). Frequency of the Duffy-null allele (rs2814778; an African ancestral variant adopted under selective pressure as protection against malaria) was associated with TNBC-specific risk (P < 0.0001), quantified West African Ancestry (P < 0.0001) and was more common in AA, Ghanaians, and TNBC cases. Additionally, rs4849887 was significantly associated with overall BC risk, and both rs2363956 and rs13000023 were associated with TNBC-specific risk, although none as strongly as the Duffy-null variant. CONCLUSIONS: West African ancestry is strongly correlated with TNBC status, as well as germline variants related to BC risk. The Duffy-null allele was associated with TNBC risk in our cohort.


Subject(s)
Black or African American/genetics , Disease Susceptibility/epidemiology , Germ-Line Mutation/genetics , Receptor, ErbB-2/genetics , Triple Negative Breast Neoplasms/genetics , Adult , Africa South of the Sahara/ethnology , Aged , Case-Control Studies , Databases, Factual , Female , Ghana/ethnology , Humans , Incidence , Internationality , Middle Aged , Receptors, Estrogen/genetics , Receptors, Progesterone/genetics , Risk Assessment , Triple Negative Breast Neoplasms/ethnology , Triple Negative Breast Neoplasms/pathology , United States
10.
J Glob Oncol ; 4: 1-8, 2018 10.
Article in English | MEDLINE | ID: mdl-30307804

ABSTRACT

PURPOSE: Population-based incidence rates of breast cancers that are negative for estrogen receptor (ER), progesterone receptor, and human epidermal growth factor receptor 2/ neu (triple-negative breast cancer [TNBC]) are higher among African American (AA) compared with white American (WA) women, and TNBC prevalence is elevated among selected populations of African patients. The extent to which TNBC risk is related to East African versus West African ancestry, and whether these associations extend to expression of other biomarkers, is uncertain. METHODS: We used immunohistochemistry to evaluate estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2/ neu, androgen receptor and aldehyde dehydrogenase 1 (ALDH1) expression among WA (n = 153), AA (n = 76), Ethiopian (Eth)/East African (n = 90), and Ghanaian (Gh)/West African (n = 286) patients with breast cancer through an institutional review board-approved international research program. RESULTS: Mean age at diagnosis was 43, 49, 60, and 57 years for the Eth, Gh, AA, and WA patients, respectively. TNBC frequency was higher for AA and Gh patients (41% and 54%, respectively) compared with WA and Eth patients (23% and 15%, respectively; P < .001) Frequency of ALDH1 positivity was higher for AA and Gh patients (32% and 36%, respectively) compared with WA and Eth patients (23% and 17%, respectively; P = .007). Significant differences were observed for distribution of androgen receptor positivity: 71%, 55%, 42%, and 50% for the WA, AA, Gh, and Eth patients, respectively ( P = .008). CONCLUSION: Extent of African ancestry seems to be associated with particular breast cancer phenotypes. West African ancestry correlates with increased risk of TNBC and breast cancers that are positive for ALDH1.


Subject(s)
Breast Neoplasms/ethnology , Breast Neoplasms/genetics , Gene Expression Regulation, Neoplastic , Isoenzymes/genetics , Receptors, Androgen/genetics , Retinal Dehydrogenase/genetics , Adult , Black or African American/genetics , Aldehyde Dehydrogenase 1 Family , Biomarkers, Tumor , Black People/genetics , Breast Neoplasms/enzymology , Breast Neoplasms/metabolism , Ethiopia , Female , Ghana , Humans , Immunohistochemistry , Middle Aged , Receptor, ErbB-2/genetics , Receptors, Estrogen/genetics , Receptors, Progesterone/genetics , Triple Negative Breast Neoplasms/enzymology , Triple Negative Breast Neoplasms/ethnology , Triple Negative Breast Neoplasms/genetics , Triple Negative Breast Neoplasms/metabolism , United States , White People/genetics
11.
J Glob Oncol ; 3(6): 765-772, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29244986

ABSTRACT

Purpose Breast cancer, the most common cancer worldwide, is the leading cause of cancer mortality in Ghanaian women. Previous studies find Ghanaian women are diagnosed at a younger age and at more advanced stages (III and IV), and have tumors with characteristics similar to African American women. We sought to remedy gaps in knowledge about breast cancer survival in Ghana and its relation to demographic and biologic factors of the tumors at diagnosis to assist in cancer control and registration planning. Methods Individuals with a breast cancer diagnosis who sought care at Komfo Anokye Teaching Hospital from 2009 to 2014 were identified via medical records. Follow-up telephone interviews were held to assess survival. Kaplan-Meier plots and Cox proportional hazards models assessed survival associated with clinical and demographic characteristics. Results A total of 223 patients completed follow-up and were analyzed. The median survival was 3.8 years. Approximately 50% of patients were diagnosed with grade 3 tumors, which significantly increased the risk of recurrence or death (hazard ratio [HR] for grade 2 versus 1, 2.98; 95% CI, 1.26 to 7.02; HR grade 3 v 1, 2.56; 95% CI, 1.08 to 6.07; P = .04). No other variables were significantly associated with survival. Conclusion Higher tumor grade was significantly associated with shorter survival, indicating impact of aggressive biology at diagnosis on higher risk of cancer spread and recurrence. Contrary to prevailing notions, telephone numbers were not reliable for follow-up. Collecting additional contact information will likely contribute to improvements in patient care and tracking. A region-wide population-based active registry is important to implement cancer control programs and improve survival in sub-Saharan Africa.


Subject(s)
Breast Neoplasms/epidemiology , Adult , Aged , Aged, 80 and over , Breast Neoplasms/mortality , Female , Ghana , Humans , Middle Aged , Poverty , Registries , Young Adult
12.
World J Pediatr Congenit Heart Surg ; 8(4): 495-501, 2017 07.
Article in English | MEDLINE | ID: mdl-28696875

ABSTRACT

The 54 countries in Africa have an estimated total annual congenital heart defect (CHD) birth prevalence of 300,486 cases. More than half (51.4%) of the continental birth prevalence occurs in only seven countries. Congenital heart disease remains primarily a pediatric health issue in Africa because of the deficient health-care systems: the adults with CHD made up just 10% of patients with CHD in Ghana, and 13.7% of patients with CHD presenting for surgery in Mozambique. With Africa's population projected to double in the next 35 years, the already deficient health systems for CHD care will suffer unbearable strain unless determined and courageous action is undertaken by the African leaders.


Subject(s)
Cardiac Surgical Procedures/methods , Health Services Accessibility , Heart Defects, Congenital/surgery , Adult , Africa/epidemiology , Heart Defects, Congenital/epidemiology , Humans , Prevalence , Socioeconomic Factors , Survival Rate/trends
13.
World J Pediatr Congenit Heart Surg ; 7(5): 592-9, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27587494

ABSTRACT

BACKGROUND: The outcome of children born with conotruncal heart defects may serve as an indication of the status of pediatric cardiac care in sub-Saharan Africa (SSA). This study was undertaken to determine the outcome of children born with conotruncal anomalies in SSA, regarding access to treatment and outcomes of surgical intervention. METHODS: From our institution in Ghana, we retrospectively analyzed the outcomes of surgery, in the two-year period from June 2013 to May 2015. The birth prevalence of congenital heart defects (CHDs) in SSA countries was derived by extrapolation using an incidence of 8 per 1,000 live births for CHDs. RESULTS: The birth prevalence of CHDs for the 48 countries in SSA using 2013 country data was 258,875; 10% of these are presumed to be conotruncal anomalies. Six countries (Nigeria, Democratic Republic of the Congo, Ethiopia, Tanzania, Uganda, and Kenya) accounted for 53.5% of the birth prevalence. In Ghana, 20 patients (tetralogy of Fallot [TOF], 17; pulmonary atresia, 3) underwent palliation and 50 (TOF, 36; double-outlet right ventricle, 14) underwent repair. Hospital mortality was 0% for palliation and 4% for repair. Only 6 (0.5%) of the expected 1,234 cases of conotruncal defects underwent palliation or repair within two years of birth. CONCLUSION: Six countries in SSA account for more than 50% of the CHD burden. Access to treatment within two years of birth is probably <1%. The experience from Ghana demonstrates that remarkable surgical outcomes are achievable in low- to middle-income countries of SSA.


Subject(s)
Cardiac Surgical Procedures/methods , Health Policy , Health Services Accessibility , Heart Defects, Congenital/surgery , Adolescent , Adult , Africa South of the Sahara/epidemiology , Child , Child, Preschool , Female , Follow-Up Studies , Heart Defects, Congenital/economics , Heart Defects, Congenital/epidemiology , Hospital Mortality/trends , Humans , Incidence , Infant , Infant, Newborn , Male , Prevalence , Retrospective Studies , Socioeconomic Factors , Survival Rate/trends , Young Adult
14.
Ann Surg Oncol ; 23(12): 3843-3849, 2016 11.
Article in English | MEDLINE | ID: mdl-27469125

ABSTRACT

INTRODUCTION: Triple-negative breast cancer (TNBC) is more common among African American (AA) and western sub-Saharan African breast cancer (BC) patients compared with White/Caucasian Americans (WA) and Europeans. Little is known about TNBC in east Africa. METHODS: Invasive BC diagnosed 1998-2014 were evaluated: WA and AA patients from the Henry Ford Health System in Detroit, Michigan; Ghanaian/west Africans from the Komfo Anokye Teaching Hospital in Kumasi, Ghana; and Ethiopian/east Africans from the St. Paul's Hospital Millennium Medical College in Addis Ababa, Ethiopia. Histopathology and immunohistochemistry for estrogen receptor (ER), progesterone receptor (PR), and HER2/neu expression was performed in Michigan on formalin-fixed, paraffin-embedded samples from all cases. RESULTS: A total of 234 Ghanaian (mean age 49 years), 94 Ethiopian (mean age 43 years), 272 AA (mean age 60 years), and 321 WA (mean age 62 years; p = 0.001) patients were compared. ER-negative and TNBC were more common among Ghanaian and AA compared with WA and Ethiopian cases (frequency ER-negativity 71.1 and 37.1 % vs. 19.8 and 28.6 % respectively, p < 0.0001; frequency TNBC 53.2 and 29.8 % vs. 15.5 and 15.0 %, respectively, p < 0.0001). Among patients younger than 50 years, prevalence of TNBC remained highest among Ghanaians (50.8 %) and AA (34.3 %) compared with WA and Ethiopians (approximately 16 % in each; p = 0.0002). CONCLUSIONS: This study confirms an association between TNBC and West African ancestry; TNBC frequency among AA patients is intermediate between WA and Ghanaian/West Africans consistent with genetic admixture following the west Africa-based trans-Atlantic slave trade. TNBC frequency was low among Ethiopians/East Africans; this may reflect less shared ancestry between AA and Ethiopians.


Subject(s)
Black or African American , Triple Negative Breast Neoplasms/ethnology , Triple Negative Breast Neoplasms/metabolism , White People , Adult , Black or African American/statistics & numerical data , Ethiopia , Female , Ghana/epidemiology , Humans , Middle Aged , Neoplasm Staging , Phenotype , Prevalence , Receptor, ErbB-2/metabolism , Receptors, Estrogen/metabolism , Receptors, Progesterone/metabolism , Triple Negative Breast Neoplasms/pathology , United States/epidemiology , White People/statistics & numerical data
15.
J Glob Oncol ; 2(5): 302-310, 2016 Oct.
Article in English | MEDLINE | ID: mdl-28717716

ABSTRACT

Women with African ancestry in western, sub-Saharan Africa and in the United States represent a population subset facing an increased risk of being diagnosed with biologically aggressive phenotypes of breast cancer that are negative for the estrogen receptor, the progesterone receptor, and the HER2/neu marker. These tumors are commonly referred to as triple-negative breast cancer. Disparities in breast cancer incidence and outcome related to racial or ethnic identity motivated the establishment of the International Breast Registry, on the basis of partnerships between the Komfo Anokye Teaching Hospital in Kumasi, Ghana, the University of Michigan Comprehensive Cancer Center in Ann Arbor, Michigan, and the Henry Ford Health System in Detroit, Michigan. This research collaborative has featured educational training programs as well as scientific investigations related to the comparative biology of breast cancer in Ghanaian African, African American, and white/European American patients. Currently, the International Breast Registry has expanded to include African American patients throughout the United States by partnering with the Sisters Network (a national African American breast cancer survivors' organization) and additional sites in Ghana (representing West Africa) as well as Ethiopia (representing East Africa). Its activities are now coordinated through the Henry Ford Health System International Center for the Study of Breast Cancer Subtypes. Herein, we review the history and results of this international program at its 10-year anniversary.

16.
Ann Surg Oncol ; 22(12): 3831-5, 2015 Nov.
Article in English | MEDLINE | ID: mdl-25743329

ABSTRACT

BACKGROUND: The androgen receptor (AR) is a commonly-expressed hormone receptor in breast cancer and may be a marker of response to targeted anti-androgen therapy, a particularly attractive option for triple-negative breast cancer (TNBC). Gene expression studies suggest that ARs may distinguish a luminal/AR TNBC subtype from stem cell-like subtypes. TNBC frequency is two to three times higher in African American and African breast cancers compared with White American and European breast cancers, yet little is known regarding TNBC subtypes in high-frequency African-ancestry populations. We evaluated ARs and the mammary stem cell marker aldehyde dehydrogenase 1 (ALDH1) among breast cancers from Ghana, Africa. METHODS: Overall, 147 formalin-fixed, paraffin-embedded invasive breast cancers from the Komfo Anoyke Teaching Hospital in Ghana were studied at the University of Michigan, and analyzed immunohistochemically for estrogen receptor (ER), progesterone receptor (PR), HER2/neu, ALDH1, and AR expression. RESULTS: The median age of patients was 45 years. Only 31 cases (21 %) were ER-positive, and 14 (10 %) were HER2-positive; 89 (61 %) were TNBCs. For the entire group, 44 % were AR-positive and 45 % were ALDH1-positive. ER/PR-positive tumors were more likely to be AR-positive compared with ER/PR-negative tumors (87 vs. 26 %; p < 0.0001), but there was no association between ALDH1 and AR expression. Among the TNBC cases, 45 % were ALDH1-positive and 24 % were AR-positive. ALDH1 positivity was associated with AR positivity within the subset of TNBC (36 vs. 14 %; p = 0.019). CONCLUSION: We confirmed other studies showing a high frequency of TNBC in Africa. Surprisingly, ALDH1 was found to correlate with AR expression among TNBC, suggesting that novel TNBC subtypes may exist among populations with African ancestry.


Subject(s)
Carcinoma, Ductal, Breast/chemistry , Carcinoma, Lobular/chemistry , Isoenzymes/analysis , Receptors, Androgen/analysis , Retinal Dehydrogenase/analysis , Triple Negative Breast Neoplasms/chemistry , Adult , Aldehyde Dehydrogenase 1 Family , Carcinoma, Ductal, Breast/epidemiology , Carcinoma, Lobular/epidemiology , Female , Ghana/epidemiology , Humans , Middle Aged , Prevalence , Receptor, ErbB-2/analysis , Receptors, Estrogen/analysis , Receptors, Progesterone/analysis , Triple Negative Breast Neoplasms/epidemiology
17.
PLoS One ; 9(4): e94491, 2014.
Article in English | MEDLINE | ID: mdl-24722666

ABSTRACT

Most antiviral treatment options target the invading pathogen and unavoidably encounter loss of efficacy as the pathogen mutates to overcome replication restrictions. A good strategy for circumventing drug resistance, or for pathogens without treatment options, is to target host cell proteins that are utilized by viruses during infection. The small molecule WP1130 is a selective deubiquitinase inhibitor shown previously to successfully reduce replication of noroviruses and some other RNA viruses. In this study, we screened a library of 31 small molecule derivatives of WP1130 to identify compounds that retained the broad-spectrum antiviral activity of the parent compound in vitro but exhibited improved drug-like properties, particularly increased aqueous solubility. Seventeen compounds significantly reduced murine norovirus infection in murine macrophage RAW 264.7 cells, with four causing decreases in viral titers that were similar or slightly better than WP1130 (1.9 to 2.6 log scale). Antiviral activity was observed following pre-treatment and up to 1 hour postinfection in RAW 264.7 cells as well as in primary bone marrow-derived macrophages. Treatment of the human norovirus replicon system cell line with the same four compounds also decreased levels of Norwalk virus RNA. No significant cytotoxicity was observed at the working concentration of 5 µM for all compounds tested. In addition, the WP1130 derivatives maintained their broad-spectrum antiviral activity against other RNA viruses, Sindbis virus, LaCrosse virus, encephalomyocarditis virus, and Tulane virus. Thus, altering structural characteristics of WP1130 can maintain effective broad-spectrum antiviral activity while increasing aqueous solubility.


Subject(s)
Antiviral Agents/pharmacology , Enzyme Inhibitors/pharmacology , Nitriles/pharmacology , Pyridines/pharmacology , Small Molecule Libraries/pharmacology , Ubiquitin-Specific Proteases/antagonists & inhibitors , Virus Replication/drug effects , Animals , Antiviral Agents/chemistry , Cell Line , Cyanoacrylates , Encephalomyocarditis virus/drug effects , Encephalomyocarditis virus/physiology , Enzyme Inhibitors/chemistry , Host-Pathogen Interactions , Humans , La Crosse virus/drug effects , La Crosse virus/physiology , Macrophages/drug effects , Macrophages/virology , Mice , Nitriles/chemistry , Norovirus/drug effects , Norovirus/physiology , Norwalk virus/drug effects , Norwalk virus/physiology , Primary Cell Culture , Pyridines/chemistry , Sindbis Virus/drug effects , Sindbis Virus/physiology , Small Molecule Libraries/chemistry , Structure-Activity Relationship , Ubiquitin-Specific Proteases/metabolism
18.
Int Perspect Sex Reprod Health ; 39(1): 42-6, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23584467

ABSTRACT

Maternal mortality remains a huge problem in the developing world, especially in Sub-Saharan Africa.1 According to the World Health Organization, efforts intended to decrease maternal deaths need to recognize and address unsafe abortions as a significant contributor to the high rates of maternal mortality found in developing countries.2,3 In Africa, where abortions are highly restricted, 680 women die per 100,000 abortions, compared with 0.2-1.2 women per 100,000 in developed countries, where most abortions are legal.4.


Subject(s)
Abortion, Induced , Family Planning Services/education , Fellowships and Scholarships , Internationality , Patient Safety , Abortion, Induced/mortality , Female , Ghana/epidemiology , Humans , Maternal Mortality/trends , Pregnancy
19.
Pan Afr Med J ; 12: 18, 2012.
Article in English | MEDLINE | ID: mdl-22826742

ABSTRACT

BACKGROUND: Postoperative junctional ectopic tachycardia (JET) is a rare and transient phenomenon occurring after repair of congenital heart defects. Report on this arrhythmia in the subregion is rare. We set out to determine the incidence of this arrhythmia and review the treatment and outcomes of treatment in our centre. METHODS: Retrospective search of the records of all patients aged 18 years and below admitted into the intensive care unit (ICU) following repair or palliation of a congenital heart defect over 5 years, from January 1, 2006 to December 31, 2010. A review of clinical notes, operative records, anaesthetic charts, cardiopulmonary bypass (CPB) records, nursing observation charts, electrocardiograms (ECGs) and out-patient follow-up records was undertaken. RESULTS: 510 children under 18 years were enlisted. 7 cases of postoperative JET were recorded, (1.37%). 184 (36.1%) of these were performed under CPB. All JET cases were from cases done under CPB, 3.8%. Median age was 3 years and median weight 11.3 kg. No patient was febrile at diagnosis. 4 patients had amiodarone administration, 5 had magnesium sulphate infusion, 2 patients had direct current shock (DCS) whilst 3 patients had all three therapeutic modalities. All patients had control of the arrhythmia with conversion to sinus rhythm and no recurrence. CONCLUSION: We report a JET incidence of 1.37% among children undergoing CPB for repair of congenital heart defects. We demonstrate the therapeutic effectiveness of amiodarone, magnesium sulphate infusions and DCS alone or in combination in the management of JET on various substrates with good outcome.


Subject(s)
Heart Defects, Congenital/surgery , Postoperative Complications/therapy , Tachycardia, Ectopic Junctional/therapy , Child , Child, Preschool , Combined Modality Therapy , Ghana , Humans , Infant , Retrospective Studies
20.
Hum Resour Health ; 9: 13, 2011 May 21.
Article in English | MEDLINE | ID: mdl-21600002

ABSTRACT

BACKGROUND: The ability of many countries to achieve national health goals such as the Millennium Development Goals remains hindered by inadequate and poorly distributed health personnel, including doctors. The distribution of doctors in Ghana is highly skewed, with a majority serving in two major metropolitan areas (Accra and Kumasi), and inadequate numbers in remote and rural districts. Recent policies increasing health worker salaries have reduced migration of doctors out of Ghana, but made little difference to distribution within the country. This qualitative study was undertaken to understand how practicing doctors and medical leaders in Ghana describe the key factors reducing recruitment and retention of health professionals into remote areas, and to document their proposed policy solutions. METHODS: In-depth interviews were carried out with 84 doctors and medical leaders, including 17 regional medical directors and deputy directors from across Ghana, and 67 doctors currently practicing in 3 regions (Greater Accra, Brong Ahafo, and Upper West); these 3 regions were chosen to represent progressively more remote distances from the capital of Accra. RESULTS AND DISCUSSION: All participants felt that rural postings must have special career or monetary incentives given the loss of locum (i.e. moonlighting income), the higher workload, and professional isolation of remote assignments. Career 'death' and prolonged rural appointments were a common fear, and proposed policy solutions focused considerably on career incentives, such as guaranteed promotion or a study opportunity after some fixed term of service in a remote or hardship area. There was considerable stress placed on the need for rural doctors to have periodic contact with mentors through rural rotation of specialists, or remote learning centers, and reliable terms of appointment with fixed end-points. Also raised, but given less emphasis, were concerns about the adequacy of clinical equipment in remote facilities, and remote accommodations. CONCLUSIONS: In-depth discussions with doctors suggest that while salary is important, it is career development priorities that are keeping doctors in urban centers. Short-term service in rural areas would be more appealing if it were linked to special mentoring and/or training, and led to career advancement.

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