Ki-67, p53 and BCL-2 Expressions and their Association with Clinical Histopathology of Breast Cancer among Women in Tanzania

Gene expression and anticancer evaluation of Kigelia africana (Lam.) Benth. Extracts using MDA-MB-231 and MCF-7 cell lines

In recent years, a cancer research trend has shifted towards identifying novel therapeutic compounds from natural assets for the management of cancer. In this study, we aimed to assess the cytotoxic activity of Kigelia Africana (KA) extracts on breast cancer (MDA-MB-231 and MCF-7) and noncancerous kidney cells (HEK-293T) to develop an efficient anticancer medication. We used gas chromatography mass spectrometry (GC-MS to analyze the constituents of EKA and HKA extracts meanwhile the crystal violet and the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assays were used to examine the possible cytotoxic effects of plant extracts on our cancer cell lines along with non-cancerous control. The quantitative real-time PCR (RT-PCR) was run on cell samples to evaluate the differential expression of cell proliferative markers of cancer (BCL-2 and TP53). These phytochemicals have been reported to have binding affinity for some other growth factors and receptors as well which was evaluated by the in-silico molecular docking against Bcl2, EGFR, HER2, and TP53. Our Morphological observation showed a significant difference in the cell morphology and proliferation potential which was decreased under the effect of plant extracts treatment as compared to the control samples. The ethanol extract exhibited a marked antiproliferative activity towards MDA-MB-231 and MCF-7 cell lines with IC50 = 20 and 32 μg/mL, respectively. Quantitative RT-PCR gene expression investigation revealed that the IC50 concentration of ethanolic extract regulated the levels of mRNA expression of apoptotic genes. With the target and active binding site amino acids discovered in the molecular docking investigation, TP53/Propanoic acid, 3-(2, 3, 6-trimethyl-1, 4-dioxaspiro [4.4] non-7-yl)-, methyl ester (-7.1 kcal/mol) is the best-docked ligand. The use of this plant in folk remedies justifies its high in vitro anti-cancer capabilities. This work highlights the role of phytochemicals in the inhibition of cancer proliferation. Based on all these findings, it can be concluded that EKA extract has promising anti-proliferative effect on cancerous cells but more study is required in future to further narrow down the active ingredients of total crude extract with specific targets in cancer cells.

Clinicopathological importance of Bcl-2 and p53 in postmenopausal triple-negative breast carcinoma and association with age

Appropriate biomarkers are required to predict the clinical outcome of triple-negative breast cancer (TNBC). In this study, we focused on the clinical importance of two representative tumor-associated proteins, Bcl-2 and p53. Bcl-2 expression is usually related to estrogen receptor expression and a favorable outcome in breast cancer. TNBC has been reported to show a high frequency of p53 positivity suggesting TP53 mutations. The expressions of Bcl-2 and p53 were immunohistochemically examined in TNBC involving two age groups of postmenopausal women (≥75 y/o, n = 75; 55-64 y/o, n = 47), who underwent surgery without neoadjuvant therapy. We examined their associations with each other, or with clinicopathological factors including the outcome. Bcl-2 expression was inversely correlated with androgen receptor, apocrine morphology, and p53 expressions, and was an independent predictor of a poor outcome in total or in younger women. p53 positivity was associated with a more favorable outcome than p53 negativity in the younger group. In combined analyzes, none of the twenty Bcl-2-negative/p53-positive cases in the younger group exhibited recurrence, resulting in the independent favorable predictive value of Bcl-2-negative/p53-positive. The anti-apoptotic nature of Bcl-2 may be apparent in TNBC. The excellent outcome of Bcl-2-negative/p53-positive cases in the younger group warrants further combined investigation of Bcl-2/p53 in TNBC.

Down-regulation of human papillomavirus E6 oncogene and antiproliferative effect of Schisandra chinensis and Pueraria lobata natural extracts on Hela cell line

ETHNOPHARMACOLOGICAL RELEVANCE

Cervical cancer is one of the most common malignancies in women that continues to be a public health problem worldwide. Human papillomavirus (HPV) infection is closely related as the causative agent of almost all cases of cervical cancer. Currently, there is no effective treatment for the persistence of HPV. Although vaccines have shown promising results in recent years, they are still a costly strategy for developing countries and have no therapeutic effect on existing infections, which is why the need arises to search for new strategies that can be used in treatment, suppressing oncogenic HPV and disease progression. Extracts of Schisandra Chinensis and Pueraria lobata have been used in traditional medicine, and it has been shown in recent years that some of their bioactive compounds have pharmacological, antioxidant, antitumor, apoptotic, and proliferation effects in HPV-positive cells. However, its mechanism of action has yet to be fully explored.

AIM OF THE STUDY

The following study aimed to determine the chemical composition, antioxidant activity, and potential antiproliferative and viral oncogene effects of natural extracts of S. chinensis and P. lobata on HPV-18 positive cervical cancer cells.

MATERIALS AND METHODS

The HPV-18-positive HeLa cells were treated for 24 and 48 h with the ethanolic extracts of S chinensis and P. lobata. Subsequently, cell viability was evaluated using the resazurin method, the effect on the cell cycle of the extracts (1.0, 10, and 100 μg/mL) was measured by flow cytometry, the gene of expression of the E6/E7, P53, BCL-2, and E2F-1 were determined by RT-PCR and the protein expression of p53, Ki-67, x|and Bcl-2 by immunohistochemistry. Additionally, the chemical characterization of the two extracts was carried out using LC-MS, and the total phenolics content (TPC), Total flavonoid content (TFC), and DPPH radical scavenging capacity were determined. Data were analyzed using the Mann-Whitney and Kruskal Wallis U test with GraphPad Prism 6 software.

RESULTS

The natural extracts of Schisandra chinensis and Pueraria lobata induced down-regulation of E6 HPV oncogene (p<0.05) and a strong up-regulation of P53 (p<0.05), E2F-1 (p<0.05), and Bcl-2 (p<0.05) gene expression. Simultaneously, the natural extracts tend to increase the p53 protein levels and arrest the cell cycle of HeLa in the G1/S phase (p<0.05). Investigated extracts were characterized by the occurrence of bioactive lignans and isoflavones in S. chinensis and P. lobata, respectively.

CONCLUSION

The extracts of S. chinensis and P. lobata within their chemical characterization mainly present lignan and isoflavone-type compounds, which are probably responsible for inhibiting the expression of the HPV E6 oncogene and inducing an increase in the expression of p53, Bcl -2 and E2F-1 producing cell cycle detection in S phase in HeLa cells. Therefore, these extracts are good candidates to continue studying their antiviral and antiproliferative potential in cells transformed by HPV.

Association study of Bif-1 gene expression with histopathological characteristics and hormone receptors in breast cancer

BACKGROUND

Breast cancer is a heterogeneous disease that has various clinical outcomes. Bax-interacting factor-1 (Bif-1) is a member of the endophilin B family that generates the pro-apoptotic BCL2-Associated X (BAX) protein in response to apoptotic signals. Lack of Bif-1 inhibits the intrinsic pathway of apoptosis and enhancements the risk of tumor genesis. The present study aimed to investigate the relationship between hormone receptors (ER, PR, and HER2) status and different levels of Bif-1 gene expression in breast cancer patients.

METHODS

Bif-1 gene expression was evaluated in 50 breast cancer tumors and 50 normal breast mammary tissues using the SYBR Green real-time RT-PCR technique. Multivariate and univariate analyses were used to appraise the relationship between the prognostic significance of the Bif-1 gene using SPSS software. In this study, the Bif-1 was selected as a candidate for a molecular biomarker and its expression status in breast cancer patients with hormone receptors (ER, RR, and HER2) compared to patients without these hormone receptors.

RESULTS

The study showed that the relative expression of the Bif-1 gene in tissues of patients with hormone receptors in breast cancer compared to those without hormone receptors was not statistically significant. The expression levels of the Bif-1 gene in different groups were evaluated for hormone receptor status. No significant relationship was found between the Bif-1 gene expression and hormone receptors (ER, PR, and HER2) (p > 0.05).

CONCLUSION

Bif-1 gene expression may be a useful prognostic marker in breast cancer.

Breast cancer in East Africa: Prevalence and spectrum of germline SNV/indel and CNVs in BRCA1 and BRCA2 genes among breast cancer patients in Tanzania

BACKGROUND

Growing prevalence and aggressiveness of breast cancer (BC) among East African women strongly indicate that the genetic risk factor implicated in the etiology of the disease may have a key role. Germline pathogenic variants in BRCA1 and BRCA2 (BRCA1/2) are known to increase the lifetime risk of BC. This study investigated the prevalence and spectrum of germline single nucleotide variant/insertion and deletion (SNV/indel), and copy number variations (CNVs) in BRCA1/2 among Tanzanian BC patients, and evaluated the associations of identified variants with patient's socio-demographic and histopathological characteristics.

METHODS

One hundred BC patients were examined for BRCA1/2 variants using next-generation sequencing (NGS). Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) assay were performed for the confirmation of SNV/indel and CNVs, respectively.

RESULTS

Six germline SNV/indel pathogenic variants were detected from six unrelated patients. Five of these variants were identified in BRCA1, and one in BRCA2. We also identified, in one patient, one variant of uncertain clinical significance (VUS). CNV was not detected in any of the BC patients. Furthermore, we found that in our cohort, BRCA1/2 variant carriers were triple-negative BC patients (p = 0.019).

CONCLUSIONS

Our study provides first insight into BC genetic landscape by the use of NGS in the under-represented East African Tanzanian populations. Our findings support the importance of genetic risk factors in BC etiology in Tanzania and showed a relatively high overall prevalence (6%) of germline BRCA1/2 pathogenic variants in BC patients. Therefore, our results indicate that BRCA1/2 pathogenic variants may well contribute to BC incidence in Tanzania. Thus, the identification of frequent variants in BRCA1/2 genes will enable implementation of rapid, inexpensive population-specific BRCA1/2 genetic testing, particularly for triple-negative BC patients known for their high prevalence in Tanzania. This will, in turn, greatly contributes to provide effective therapeutic strategies.

The distribution of reproductive risk factors disclosed the heterogeneity of receptor-defined breast cancer subtypes among Tanzanian women

Background

Recent epidemiological studies suggest that reproductive factors are associated with breast cancer (BC) molecular subtypes. However, these associations have not been thoroughly studied in the African populations. The present study aimed to investigate the prevalence of BC molecular subtypes and assess their association with reproductive factors in Tanzanian BC patients.

Methods

This hospital-based case-only cross-sectional study consisted of 263 histologically confirmed BC patients in Tanzania. Clinico-pathological data, socio-demographic characteristics, anthropometric measurements, and reproductive risk factors were examined using the Chi-square test and one-way ANOVA. The association among reproductive factors and BC molecular subtypes was analyzed using multinomial logistic regression. The heterogeneity of the associations was assessed using the Wald test.

Results

We found evident subtype heterogeneity for reproductive factors. We observed that post-menopausal status was more prevalent in luminal-A subtype, while compared to luminal-A subtype, luminal-B and HER-2 enriched subtypes were less likely to be found in post-menopausal women (OR: 0.21, 95%CI 0.10–0.41, p = 0.001; OR: 0.39, 95%CI 0.17–0.89, p = 0.026, respectively). Also, the luminal-B subtype was more likely to be diagnosed in patients aged ≤ 40 years than the luminal-A subtype (OR: 2.80, 95%CI 1.46–5.32, p = 0.002). Women who had their first full-term pregnancy at < 30 years were more likely to be of luminal-B (OR: 2.71, 95%CI 1.18–4.17, p = 0.018), and triple-negative (OR: 2.28, 95%CI 1.02–4.07, p = 0.044) subtypes relative to luminal-A subtype. Furthermore, we observed that breastfeeding might have reduced odds of developing luminal-A, luminal-B and triple-negative subtypes. Women who never breastfed were more likely to be diagnosed with luminal-B and triple-negative subtypes when compared to luminal-A subtype (OR: 0.46, 95%CI 0.22–0.95, p = 0.035; OR: 0.41, 95%CI 0.20–0.85, p = 0.017, respectively).

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Conclusion

Our results are the first data reporting reproductive factors heterogeneity among BC molecular subtypes in Tanzania. Our findings suggest that breast-feeding may reduce the likelihood of developing luminal-A, luminal-B, and triple-negative subtypes. Meanwhile, the first full-term pregnancy after 30 years of age could increase the chance of developing luminal-A subtype, a highly prevalent subtype in Tanzania. More interventions to promote modifiable risk factors across multiple levels may most successfully reduce BC incidence in Africa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-021-01536-6.

Expression analysis of p16 and TOP2A protein biomarkers in cervical cancer lesions and their correlation with clinico-histopathological characteristics in a referral hospital, Tanzania

Introduction

Biomarkers yield important information for early diagnosis of cervical cancer. However, they are rarely applied for prognosis of cervical cancer in Tanzania, where visual inspection assay with acetic acid or Lugol’s iodine and Pap test are being used as the standard screening/ diagnostic methods.

Methods

This was a retrospective hospital-based cross-sectional study that was conducted to assess cyclin-dependent kinase inhibitor (p16) and topoisomerase II-alpha (TOP2A) proteins expression among women seeking cervical cancer care at Kilimanjaro Christian Medical Centre, Tanzania between May 1, 2017 and May 10, 2018. Immunohistochemistry technique was used to detect the expressions of p16 and TOP2A proteins from the retrieved formalin-fixed and paraffin-embedded (FFPE) cervical biopsies.

Results

A total of 145 patients, with a mean age of 52.1 ± 12.9 years, were included in this study. Upon immunohistochemistry staining, 103 (71.0%) and 90 (62.1%) were p16 and TOP2A positive respectively. There was a strong association between histopathological class and p16/TOP2A expression levels (Fisher’s exact test, p<0.001). Moreover, there was a strong positive correlation between p16/TOP2A and cancerous cervical lesions (Spearman’s rank correlation coefficients = 0.833 and 0.687, p = 0.006 and 0.005, respectively). The age-adjusted odds ratio for predicting cervical cancer lesions were independently significant for p16/TOP2A biomarkers in FFPE cervical tissues [p16: OR = 1.142 (95% CI: 1.059–1.232, p<0.001) and TOP2A: OR = 1.046 (95% CI: 1.008–1.085, p = 0.015)]. Importantly, the diagnostic performance of p16 was higher than that of TOP2A in the diagnosis of cancerous lesions from non-cancerous cervical lesions (sensitivity: 97.2% versus 77.6%, accuracy: 92.8% versus 87.8%, respectively).

Conclusion

Our study has highlighted that over-expression of TOP2A is related to the grade of cervical intraepithelial neoplasia but does not predict prognosis in cervical cancer. Similarly, expression of p16 is related to degree of histological dysplasia and malignancy, suggesting its prognostic and predictive value in the management of cervical cancers. Further bigger studies are needed to validate their applications in the early diagnosis of cervical cancer.

Immunohistochemical Characterization of Bcl-2 in Oral Potentially Malignant Disorders

Bcl-2 is a group of apoptotic proteins that play a key role in cellular homeostasis. Overexpression of Bcl-2 has been associated with the poor prognosis of oral squamous cell carcinoma (OSCC). The aim of this study is to analyze the immunohistochemical expression of Bcl-2 in healthy oral mucosa, different oral potentially malignant disorders and OSCC, and to determine its diagnostic value. A retrospective observational study was carried out in the Oral Medicine Unit of the University of Santiago de Compostela. All the clinicopathologic data were collected and paraffin-embedded blocks were available to perform the immunohistochemistry study with Bcl-2. We studied 18 fibromas, 15 OSCC, 29 oral leukoplakia lesions (OL), 59 oral lichen planus (OLP) cases, and 16 healthy controls. OL with epithelial dysplasia (31.2%) showed the highest expression of Bcl-2 and OLP (1.9%) showed the lowest expression of Bcl-2 (P=0.025). Receiver operating characteristics curves showed that the detection of Bcl-2 enables discrimination between OL and OLPs (sensitivity: 58.6%, specificity of 99.32%). Bcl-2 negative expression in the OLP diagnosis obtained an odds ratio of 13.750 (95% confidence interval: 3.354-56.369; P<0.0001) and the positive expression in the OL 4.468 (95% confidence interval: 1.889-10.565; P=0.001). Bcl-2 could be used as a diagnostic biomarker to study their malignant transformation.

Analysis of prognostic factors in 171 patients with myxofibrosarcoma of the trunk and extremities: a cohort study

Background

Myxofibrosarcoma (MFS) of the trunk and extremities has unique clinical features. However, it is not clear which indicators are the influencing factors of recurrence, metastasis, and survival of trunk and limb MFS. The aim of the present study was to analyze clinical features and prognosis of trunk and limb MFS.

Methods

The data of 171 patients with MFS of the trunk and extremities and a median follow-up period of 67 months from January 1999 to July 2018 were retrospectively analyzed. Risk factors for survival, recurrence and metastasis following resection of MFS of trunk and extremities were analyzed. The Kaplan-Meier method (log-rank test) was used for the univariate analysis and a Cox regression model was used for the multivariate analysis.

Results

The median age of the patients was 53 years; there were 111 males and 60 females. A total of 132 cases had French Federation of Cancer Centers grade 1, 24 cases had grade 2, and 15 cases had grade 3 MFS. The 3-year recurrence, 3-year metastasis, and 5-year survival rates were 29.2%, 19.3%, and 93.6%, respectively. Kaplan-Meier survival analysis showed that the surgical margin (χ²=22.228, P<0.001) and tumor size (χ²=6.697, P=0.010) were associated with recurrence. The surgical margin (χ²=12.353, P<0.001) and CD44 expression (χ²=5.227, P=0.022) were associated with metastasis. The multivariate analysis showed that the surgical margin [hazard ratio (HR) =3.635, 95% confidence interval (CI): 1.883-7.016, P<0.001] and tumor size (HR =1.889, 95% CI: 1.039-3.435, P=0.037) were risk factors for local recurrence. In addition, the surgical margin (HR =4.475, 95% CI: 1.918-10.438, P=0.001) and presence of CD44 (HR =3.406, 95% CI: 1.462-8.405, P=0.005) were risk factors for distant metastasis.

Conclusions

A negative surgical margin can be reduced effectively the rate of recurrence and metastasis in patients with MFS of the trunk and limbs. In addition, CD44 may be used to assess the metastatic risk of patients with MFS.

Feasibility of Fine-Needle Aspiration Biopsy and Rapid On-Site Evaluation for Immediate Triage in Breast Cancer Screening in Tanzania

PURPOSE

Clinical breast examination (CBE) is one of the most common methods used for early detection of breast cancer in low- and middle-income countries. CBE alone is limited by lack of specificity and may result in unnecessary diagnostic procedures. We evaluated the feasibility of integrating CBE, fine-needle aspiration biopsy (FNAB), and rapid on-site evaluation (ROSE) in triaging palpable breast masses for specialized cancer care.

MATERIALS AND METHODS

An intensive breast cancer screening event was conducted at a national trade fair by a multidisciplinary team of care providers targeting a healthy population in Dar es Salaam, Tanzania. All adults age ≥ 18 years were invited to participate. CBE was performed by oncologists and/or pathologists. FNAB was performed by a pathologist on palpable masses that were then categorized as benign, indeterminate, or suspicious for malignancy or definitively malignant based on ROSE.

RESULTS

A total of 208 individuals (207 females, one male; median age, 36 years; range, 18-68 years) were screened. Most (90.8%, 189 of 208) had normal findings, whereas 7.2% (15 of 208), 1% (2 of 208), and 1% (2 of 208) had a palpable mass, breast pain, and nipple discharge, respectively. Two participants had lesions too small for palpation-guided biopsy and clinically consistent with fibroadenomas; the participants were counseled, and observation was recommended. FNAB was performed on 13 breast masses, with 9 of 13 (69%) categorized as benign and 4 of 13 (31%) suspicious for malignancy. Final cytopathologic review of referred patients confirmed one case to be breast adenocarcinoma, one was suggestive of fibroadenoma, and two showed inflammations.

CONCLUSION

Integration of CBE with ROSE and FNAB was feasible in a breast cancer screening program in Tanzania. In settings with constrained resources for cancer care, this may be an effective method for triaging patients with breast masses.

The Analysis of bcl-2 in Association with p53 and Ki-67 in Triple Negative Breast Cancer and Other Molecular Subtypes in Ghana

BACKGROUND

Little is known about the role of apoptosis in the tumorigenesis and prognosis of breast cancer in Ghana. Chemotherapeutic drug efficacy partially relates to apoptosis induction, rendering it a vital target in cancer therapy with unique biomarker opportunities that have not been exploited. Aberrations in this pathway are central to tumorigenesis, tumor progression, overall tumor growth, and regression during treatment therapies. Antiapoptotic bcl-2 (gene) and p53 are known to play roles in apoptosis while Ki-67 is a proliferative marker. The aim of our study is to determine the association of bcl-2 (protein) with p53 and Ki-67 in 203 consecutive breast cancer cases over a 10-year period.

METHOD

A retrospective cross-sectional study on archival FFPE tissue blocks over a 9-year period with abstraction of clinicopathologic data. Two hundred and three consecutive and suitable FFPE blocks were selected for tissue microarray (TMA) construction, and IHC (bcl-2 (protein), Ki-67, p53, cyclin D, pan cytokeratins A and E, ER, PR, and HER2/neu) was done. Expressions of bcl-2 (protein), p53, and Ki-67 were related to histological grade, lymphovascular invasion, and molecular subtypes. SPSS version 23 was used to analyze results.

RESULTS

Most of our cases were in the fifth decade of life (31%); invasive carcinoma of no special type (NST) was predominant (87%); histological grade III (38%) was the highest; and Luminal A (19.8%), Luminal B (9.9%), HER2 (16%), and TNBC (54.3%) constituted the molecular classes. bcl-2 expression was found in 38% of the cases. Our cases also showed mutation in p53 (36.7%) and ki-67 expression (62.5%). bcl-2 (protein) and p53 significantly correlated with Luminal B and TNBC (p < 0.01). Ki-67 also correlated significantly with Luminal A and B and HER2 overexpression (p < 0.01). Premenopausal age (40-49) and histological grade inversely correlated with bcl-2 (protein) expression. p53 statistically correlated with Ki-67 (p < 0.05).

CONCLUSION

Our results show high expression of bcl-2 (protein) suggesting an important role of apoptosis in Ghanaian breast cancer cases. bcl-2 (protein), p53, and Ki-67 expressions emerged interdependently from this research and can thus be manipulated in prediction and prognosis of breast cancers in our setting.

P53-regulated lncRNA uc061hsf.1 inhibits cell proliferation and metastasis in human esophageal squamous cell cancer

The expression of long noncoding RNAs (lncRNAs) is closely associated with cancer development and progression, making these lncRNAs potentially novel therapeutic targets. In this study, we aimed to explore the potential function of lncRNA-uc061hsf.1 in esophageal squamous cell carcinoma (ESCC). The expression of lncRNA-uc061hsf.1 in ESCC tissues and cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, apoptosis, and metastasis were detected via CCK-8, flow cytometry, and Transwell assays. The interaction between p53 and lncRNA uc061hsf.1 was analyzed using luciferase reporter gene and qRT-PCR. Through this approach, we identified the novel lncRNA uc061hsf.1, which was expressed in low level in ESCC and was correlated with lymph node metastasis and poor differentiation in ESCC patients. Knockdown or overexpression of lncRNA uc061hsf.1 in ESCC cells promoted or inhibited cell proliferation and metastasis, respectively. Mechanistically, lncRNA uc061hsf.1 was induced by p53, and luciferase reporter gene confirmed that lncRNA uc061hsf.1 was a direct transcriptional target of p53. We further found that uc061hsf.1 was able to regulate expression of the transcription factor FoxA1, thereby potentially influencing tumor cell migration. In conclusion, these results suggest that p53-regulated lncRNA uc061hsf.1 is a cancer suppressor gene which is associated with tumor progression in ESCC.