Abstract P1-01-19: The role of S100A7 in microbiota mediated inflammation and breast cancer progression

Introduction

While it is accepted that inflammation is a key component of cancer development, the intricate mechanism linking the two are not fully defined. Unparalleled progress has been underway to provide better understanding of this mechanism. We investigate the role of bacterial microbiota in promoting an inflammatory environment through the induction of the pro-inflammatory molecule, S100A7, and its activation of STAT-3 signaling pathways to promote tumor growth and metastasis in breast cancer (BC).

Methods

Immune-competent mouse models of orthotopic breast cancer was used to identify and characterize populations of bacterial microbiota in the cancerous breast tissue at tumor onset. Isolated tissues were homogenized and cultured, then processed for DNA extraction. Bacterial species were identified by aligning the sequences on NCBI BLAST.

Mouse mammary tissue and tumors were analyzed for S100a7 after intraperitoneal exposure to LPS after cancer cell injections. Isolated tissues were analyzed by IHC, Western Blot analysis and real time RT-PCR.

mRNA and Protein expression using real time PCR, western blot and flow cytometry, and binding assays analyzed expression and affinity of LPS/S100A7/TLR4 in BC cell lines in vitro under varying conditions.

Protein expression and In vitro functional assays including matrigel invasion and wound closure assays determined the effect of LPS/S100A7 on TLR4 and STAT-3 expression and signaling pathways in promoting tumor invasiveness.

Results

We observed microbiota in cancerous breast tissue, which is predominantly composed of Gram-negative bacteria at tumor onset. The population of mainly gram negative bacteria at tumor initiation is unique from those populations from feces and skin. This suggests that breast tissue microbiota may be a potential source of LPS in breast tumors.

Stimulation with LPS induces secretion/expression of S100A7 in mouse mammary tissue and tumors, as well as BC cell lines. Furthermore, inhibition of LPS by polymixin B decreases S100A7 to basal levels in BC cell lines.

LPS/S100A7 combinational treatment has an additive effect on the invasive potential induced by LPS in BC cell lines as shown by invasion assays and wound closure assays. S100A7 over expression increases TLR4 expression as observed by TLR4 mRNA by real time PCR and protein by flow cytometry. Furthermore, secreted S100A7 protein promotes interaction between S100A7 protein and TLR4 receptor in cell lines with endogenous TLR4 expression.

In addition, both S100A7 and LPS stimulation of TLR4 can activate STAT3 signaling pathway, and inhibition of either S100A7 and or TLR4 impairs the invasiveness of BC cell lines.

Conclusion

A unique population of gram negative bacteria characterizes breast cancer tissues. LPS of bacterial cells walls, representative of gram negative bacteria induces S100A7, which interacts with TLR4 to activate the STAT-3 pathway in tumors. This LPS-S100A7-TLR4-STAT3 axis in turn increases the invasiveness of tumor cells to promote tumor metastasis. This suggests that microbiota plays an important role in the initiation and progression of breast cancer through regulation of the pro-inflammatory molecule S100A7.

Citation Format: Wilkie T, Zhao H, Nasser M, Ahirwar D, Mishra S, Satoskar A, Pancholi V, Ganju R. The role of S100A7 in microbiota mediated inflammation and breast cancer progression [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-01-19.

Genetic discrimination in life insurance: empirical evidence from a cross sectional survey of genetic support groups in the United Kingdom

OBJECTIVES

To gather empirical evidence on any discrimination based on genetic information shown by the insurance industry in the United Kingdom and to assess how society is likely to handle future genetic information from tests for polygenic multifactorial conditions.

DESIGN

Postal questionnaire survey.

SUBJECTS

Sample (n=7000) of members from seven British support groups for families with genetic disorders and a representative sample (n=1033) of the general public who answered questions on applying for life insurance as part of an omnibus survey.

MAIN OUTCOME MEASURES

Subjects were asked about their experiences with insurers, the medical profession, employers, and social services. Experiences with insurers are reported here.

RESULTS

Altogether 33.4% of the study group had problems when applying for life insurance compared with 5% of applicants in the omnibus survey. Thirteen per cent of study respondents from subgroups who represented no adverse actuarial risk on genetic grounds reported that their treatment by insurers seemed to represent unjustified genetic discrimination.

CONCLUSIONS

Life insurers may not be operating a consistent policy for assessing genetic information or acting in accord with the actuarial risks brought to them. The inconsistency suggests error rather than a corporate policy of discrimination based on genetic characteristics. Any future proposals for genetic testing for common or multifactorial disorders should be examined carefully.

A partial matching theory of the mirror effect in immediate probed recognition

A set of experiments on immediate probed recognition of digit triples is reported in which the variables were list length (five, six, seven, or eight triples), the probability that a probe was old (.33, .5, or .67), and whether the digit triples were presented with an auditory component or articulatory suppression. Previous work had suggested that the false alarm (FA) rate in this paradigm was lower when auditory information was available than when it was not; this observation had led to the development of the partial matching theory of immediate probed recognition, according to which FAs could arise not only as a result of unlucky guesses but also when new probes shared a first digit in common with a partially retained target triple. It was argued that partial memory representations were less likely following auditory presentation than following articulatory suppression. Partial matching theory is contrasted with the rational response theory, according to which all FAs are unlucky guesses; partial matching theory gave a better account of the present experimental data than did rational response theory. However, a logical relationship between the two theories was suggested, a consequence of which was that rational response theory could be modified to include partial matching in such a way as to account for mirror effects, not only in unusually difficult immediate probed recognition tasks, but also in the more commonly studied mixed test list paradigm involving words of high or low frequency.

Genetics and insurance in Britain: why more than just the Atlantic divides the English-speaking nations

The British Government's official advisory committee on genetics has recommended a moratorium on the disclosure of genetic test results for life insurance until predictions based on such tests can be validated as actuarially important. In contrast, the trade association of the British insurance industry believes that genetic tests relating to eight conditions can yield information useful for life insurance. Although the Government has yet to respond, the debate is already moving on to genetic testing and the funding of health care for the elderly.

Sources in science: who can we trust?

Journalists' sources of medical and scientific news seem limitless--journals, press releases, press conferences, newsletters, scientific meetings, and "tipoffs". But whether any one piece of information satisfies two important criteria-journalistic interest and scientific credibility-is another matter. Peer-reviewed journals, in particular, are perceived to be trustworthy sources. Yet, there are increasing concerns in scientific publishing about commercial pressures from pharmaceutical companies, honorary authorship, scientific error, and outright fraud, which journalists cannot be expected to detect. That is down to the scientific community, which must recognise the importance of maintaining impartial sources of public information.

Volumetric breast measurement during surgery

Unequal breasts following reduction mammaplasty sometimes provide an unfavourable result, despite careful measurements of removed tissue during surgery-Accurate comparison of breast volume during surgery could prevent this problem.-The authors have devised a simple, sterilizable, "mammasizer" which is capable of providing the surgeon with this essential information the moment he most requires it-prior to completion of surgery.