Circulating miR-30b-5p levels in plasma as a novel potential biomarker for early detection of breast cancer

BACKGROUND

Recently, microRNAs have been demonstrated to be potential non-invasive biomarkers for diagnosis, prognosis assessment or prediction of response to treatment in cancer. In this study, we evaluate the potential of miR-30b-5p as a biomarker for early diagnosis of breast cancer (BC) in tissue and plasma.

METHODS

Expression of miR-30b-5p was determined in a series of 112 BC and 40 normal breast tissues. Circulating miR-30b-5p levels in plasma samples were determined in a discovery cohort of 38 BC patients and 40 healthy donors and in a validation cohort of 83 BC patients and 83 healthy volunteers. miR-30b-5p expression was measured by quantitative real-time PCR and receiver operating characteristics curve analysis was carried out.

RESULTS

The miR-30b-5p expression was significantly lower in BC tissue than in healthy breast samples. In contrast, circulating miR-30b-5p levels were significantly higher in BC patients compared with healthy donors. Furthermore, circulating miR-30b-5p levels were significantly higher in patients with positive axillary lymph node and de novo metastatic patients. Receiver operating characteristics curve analysis demonstrated a good diagnostic potential of miR-30b-5p to detect BC even at an early stage of the disease.

CONCLUSION

Thus, we highlight the potential of miR-30b-5p as a non-invasive, fast, reproducible and cost-effective diagnostic biomarker of BC.

Combination of phenotype and polygenic risk score in breast cancer risk evaluation in the Spanish population: a case -control study

Background

In recent years, the identification of genetic and phenotypic biomarkers of cancer for prevention, early diagnosis and patient stratification has been a main objective of research in the field. Different multivariable models that use biomarkers have been proposed for the evaluation of individual risk of developing breast cancer.

Methods

This is a case control study based on a population-based cohort. We describe and evaluate a multivariable model that incorporates 92 Single-nucleotide polymorphisms (SNPs) (Supplementary Table S1) and five different phenotypic variables and which was employed in a Spanish population of 642 healthy women and 455 breast cancer patients.

Results

Our model allowed us to stratify two groups: high and low risk of developing breast cancer. The 9th decile included 1% of controls vs 9% of cases, with an odds ratio (OR) of 12.9 and a p-value of 3.43E-07. The first decile presented an inverse proportion: 1% of cases and 9% of controls, with an OR of 0.097 and a p-value of 1.86E-08.

Conclusions

These results indicate the capacity of our multivariable model to stratify women according to their risk of developing breast cancer. The major limitation of our analysis is the small cohort size. However, despite the limitations, the results of our analysis provide proof of concept in a poorly studied population, and opens up the possibility of using this method in the routine screening of the Spanish population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07584-9.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07584-9.

Nuclear PARP-1 protein overexpression is associated with poor overall survival in early breast cancer

BACKGROUND

Poly(ADP-ribose)polymerase-1 (PARP-1) is a highly promising novel target in breast cancer. However, the expression of PARP-1 protein in breast cancer and its associations with outcome are yet poorly characterized.

PATIENTS AND METHODS

Quantitative expression of PARP-1 protein was assayed by a specific immunohistochemical signal intensity scanning assay in a range of normal to malignant breast lesions, including a series of patients (N = 330) with operable breast cancer to correlate with clinicopathological factors and long-term outcome.

RESULTS

PARP-1 was overexpressed in about a third of ductal carcinoma in situ and infiltrating breast carcinomas. PARP-1 protein overexpression was associated to higher tumor grade (P = 0.01), estrogen-negative tumors (P < 0.001) and triple-negative phenotype (P < 0.001). The hazard ratio (HR) for death in patients with PARP-1 overexpressing tumors was 7.24 (95% CI; 3.56-14.75). In a multivariate analysis, PARP-1 overexpression was an independent prognostic factor for both disease-free (HR 10.05; 95% CI 5.42-10.66) and overall survival (HR 1.82; 95% CI 1.32-2.52).

CONCLUSIONS

Nuclear PARP-1 is overexpressed during the malignant transformation of the breast, particularly in triple-negative tumors, and independently predicts poor prognosis in operable invasive breast cancer.

P3-14-05: Evaluation of Residual Cancer Burden Index (RCBI) as a Predictor of Disease Free Survival in a Non-Selected Cohort of Breast Cancer Patients Treated in the Neoadjuvant Setting

INTRODUCTION: Pathologic complete response (pCR) is associated with long-term survival and is considered as the primary endpoint in neoadjuvant trials. Definition of pCR includes patients without residual disease of the breast, however the presence of nodal metastasis, minimal residual cellularity and residual in situ carcinoma were not consistently defined as pCR. These observations, lead Symmans et al to construct a new prognostic index, the RCBI, in which these important issues were incorporated. RCBI is classified into 4 different response subgroups, from RCB-0 or pCR to RCB-III or absence of response. The aim of our study was to assess the prognostic value for recurrence free survival of the RCBI in a cohort of unselected breast cancer patients treated in our institution.

PATIENTS AND METHODS: We performed a retrospective evaluation of samples of breast cancer patients treated with neoadjuvant treatment. RCBI was assessed by two highly trained pathologists. Patients included had a histological diagnosis of breast carcinoma before neoadjuvant treatment and were considered candidate for neoadjuvant therapy. Clinical variables including date and type of recurrence were obtained from clinical records. Prognostic accuracy of RCBI index was evaluated by comparison of the Kaplan-Meier survival curves of the 4 different groups of response by RCBI. Differences were assessed with log-rank.

RESULTS: Samples from 70 patients treated in the neoadjuvant setting from January 2003 to December 2006 were included in the analysis. Median age was 54.6 years (range 31–80), histhologic subtype was ductal carcinoma (87.1%), lobular carcinoma (8.5%), and other (4.2%). In biopsy, rate of estrogen receptor positive was 72.7%, progesterone receptor positive 62.1%, and rate of HER2 overexpression was 26.2%. Neoadjuvant therapy administered was anthracycline+taxanes chemotherapy (CT )in both sequential or combination schedules in 71.4%, anthracycline-based CT in 15.7%, and other in 12.9%. Most patients received from 6–10 cycles of neoadjuvant CT. 3 patients treated with only 4 cycles received adjuvant complementary CT. All patients with hormone-sensible tumors received adjuvant endocrine therapy and 20 patients received adjuvant trastuzumab. Number of responses by RCB-group was 5 patients (7.1%) with RCB-0, 12 patients (17.1%) with RCB-I, 35 (50%) with RCB-II, and 18 (25.7%) with RCB-III. With a median follow-up of 41.2 months (range 12.7−120.9 months) 22 patients (31.4%) have relapsed. Ratio of events/patients in each RCB group was 0/5 in RCB-0, 2 /12 in RCB-I, 8/35 in RCB-II and 15/18 in RCB-III. Differences in recurrence-free survival in each group was statistically significant with p=0.0002.

CONCLUSIONS: Our results suggest that RCBI might be an appropriate prognostic tool to predict disease-free survival in a non-selected population of breast cancer patients. Further validation of our results with a bigger sample size is needed.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-05.

P5-11-06: Immunohistochemistry Discordance between Primary and Recurrent Tumors in Breat Cancer. Analysis of Potential Influence of Technique Bias by Comparing Test-Results under Two Different Conditions

Introduction: Discordance in expression of estrogen (ER) or progesterone receptors (PgR) and HER2 has been previously described in several studies, having this discordance an important impact on therapeutic approach or even in survival. However it is unclear whether discordance is a reflex of a clonal differentiation to a more aggressive biological tumour or the consequence of technical biases or inter-explorer variability. We aimed to assess the role of technique biases in observed discordance between primary tumour (PT) and recurrent tumour (RT) by analyzing discordance in two different situations: routine versus optimal conditions.

Patients and methods: We conducted a retrospective study in patients (pts) diagnosed with a recurrent breast cancer in the Hospital Clinico of Valencia between January 2000 and June 2010. All patients had a previous histological diagnose of the PT and all underwent a second histological study of the RT. Discordance was assessed in terms of hormone-sensibility (HS) (any ER or PgR +) vs hormone-resistance (HR) (ER-/PgR -) and triple negativity (TN) (ER-, PgR-, HER2−) vs non-TN (any positive). Routine conditions were referred to the immunohistochemistry (IHC) assessment of the normal practice on the base of which therapeutic decisions were made. Routine conditions were performed in the Pathology Department of our institution but PT and RT were usually evaluated at different timing and ocasionally by different pathologists. In order to assess potential laboratory biases we repeated IHC analysis under optimal conditions. For these optimal conditions analyses, paired samples from both PT and RT were reassessed at the same time and tests were performed in the same way. Final determination of the results was made by two highly trained pathologists and in case of disagreement in any determination, both explorers re-assessed the sample at the same time.

We evaluated discordance between PT and RT under both conditions, and the accuracy of determinations in PT or RT between both conditions.

Results: 128 paired samples (from 64 different pts) were analysed. Median age of the series was 48.5 years (range 27–83). Recurrences were loco-regional in 14 pts (21.9%) and distant in 50 pts (78.1%). RT tissue was obtained from skin and soft-tissues in 18 pts (28.1%), lung in 11 (17.2%), bone in 10 (15.6%), lymph nodes in 10 (15.6%), pleura/peritoneum in 9 (14.1%) and liver in 6 (9.4%). Discordant cases between PT an RT in terms of HS/HR were 30.4% in routine conditions and 9.8% in optimal conditions. In terms of TN/non-TN were 14.3% in routine vs 8.2% in optimal conditions. Accuracy in results HS/HR between routine and optimal conditions was 80.7% in PT and 76.0% in RT. In results of TN/non-TN accuracy between both conditions was 94.2% in PT and 87.2% in RT.

Conclusions: Results suggest that an important rate of discordance observed in routine conditions might be strongly influenced by technique biases. However, changes observed in optimal conditions with 9.8% discordance in HS/HR and 8.2% in TN/non-TN suggest that in a small proportion of tumours, observed discordance might be explained by biological mechanisms.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-11-06.

Pharmacology of the receptors for the phorbol ester tumor promoters: multiple receptors with different biochemical properties

The phorbol ester tumor promoters and related analogs are widely used as potent activators of protein kinase C (PKC). The phorbol esters mimic the action of the lipid second messenger diacylglycerol (DAG). The aim of this commentary is to highlight a series of important and controversial concepts in the pharmacology and regulation of phorbol ester receptors. First, phorbol ester analogs have marked differences in their biological properties. This may be related to a differential regulation of PKC isozymes by distinct analogs. Moreover, it seems that marked differences exist in the ligand recognition properties of the C1 domains, the phorbol ester/DAG binding sites in PKC isozymes. Second, an emerging theme that we discuss here is that phorbol esters also target receptors unrelated to PKC isozymes, a concept that has been largely ignored. These novel receptors lacking kinase activity include chimaerins (a family of Rac-GTPase-activating proteins), RasGRP (a Ras exchange factor), and Unc-13/Munc-13 (a family of proteins involved in exocytosis). Unlike the classical and novel PKCs, these "non-kinase" phorbol ester receptors possess a single copy of the C1 domain. Interestingly, each receptor class has unique pharmacological properties and biochemical regulation. Lastly, it is well established that phorbol esters and related analogs can translocate each receptor to different intracellular compartments. The differential pharmacological properties of the phorbol ester receptors can be exploited to generate specific agonists and antagonists that will be helpful tools to dissect their cellular function.

Cloning of a DNA fragment encoding part of a 70-kDa heat shock protein of Candida albicans

Immunoscreening of a mycelial expression library with polyclonal antibodies raised against mycelial cell wall resulted in the detection of a cDNA encoding a heat shock protein of Candida albicans. Sequence analysis of a 0.8-kb cDNA subclone, 2M-1, revealed an open reading frame encoding 244 amino acids. Southern blot analysis with this fragment as a probe demonstrated hybridization to C. albicans DNA. Northern analysis showed a substantial increase in 2M RNA expression levels after cells were subjected to heat shock. Western blot analysis with 2M monospecific antibodies recognized a 70-kDa protein which was present in membrane particles and cytosolic fractions.