Here we report a preliminary study based on the application of Raman spectroscopy and surface enhanced Raman spectroscopy (SERS) to investigate the compositional differences between exosomes derived from ovarian carcinoma cells (cell line A2780) grown in normoxia (normal O 2 conditions) and hypoxia (1% O 2 conditions).Exosomes are integral to cell signalling, and are of interest in the study of how cells communicate within their environment. We are particularly interested in identifying whether hypoxia induced senescent cells can communicate via exosomes with neighbouring tumour cells, thereby causing them to become senescent and therefore radio and chemo resistant. With this goal in mind, we performed a preliminary study on the application of Raman spectroscopy and SERS to analyse the biomolecular fingerprint of both groups of exosomes and to investigate whether there exists a different biomolecular composition associated with exosomes derived from hypoxic cells in comparison to those from normoxic cells. We also applied multivariate statistical techniques for the classification of both groups of exosomes.
Background:Somatic mutations in the ERBB genes (epidermal growth factor
receptor: EGFR, ERBB2, ERBB3, ERBB4) promote oncogenesis
and lapatinib resistance in metastatic HER2+ (human epidermal growth
factor-like receptor 2) breast cancer in vitro. Our study
aimed to determine the frequency of mutations in four genes: EGFR,
ERBB2, ERBB3 and ERBB4 and to investigate
whether these mutations affect cellular behaviour and therapy response
in vitro and outcomes after adjuvant trastuzumab-based
therapy in clinical samples.Methods:We performed Agena MassArray analysis of 227 HER2+ breast cancer samples to
identify the type and frequency of ERBB family mutations.
Of these, two mutations, the somatic mutations ERBB4-V721I
and ERBB4-S303F, were stably transfected into HCC1954
(PIK3CA mutant), HCC1569 (PIK3CA wildtype) and BT474 (PIK3CA mutant, ER
positive) HER2+ breast cancer cell lines for functional in
vitro experiments.Results:A total of 12 somatic, likely deleterious mutations in the kinase and
furin-like domains of the ERBB genes (3
EGFR, 1 ERBB2, 3
ERBB3, 5 ERBB4) were identified in 7%
of HER2+ breast cancers, with ERBB4 the most frequently
mutated gene. The ERBB4-V721I kinase domain mutation
significantly increased 3D-colony formation in 3/3 cell lines, whereas
ERBB4-S303F did not increase growth rate or 3D colony
formation in vitro. ERBB4-V721I sensitized HCC1569 cells
(PIK3CA wildtype) to the pan class I PI3K inhibitor copanlisib but increased
resistance to the pan-HER family inhibitor afatinib. The combinations of
copanlisib with trastuzumab, lapatinib, or afatinib remained synergistic
regardless of ERBB4-V721I or ERBB4-S303F
mutation status.Conclusions:ERBB gene family mutations, which are present in 7% of our
HER2+ breast cancer cohort, may have the potential to alter cellular
behaviour and the efficacy of HER- and PI3K-inhibition.
Highlights
Triple negative breast cancer (TNBC) is a biological heterogeneous andn aggressive disease with a poor prognosis.
Extracellular vesicles have been shown to play a role in mediating metastasis.
Cofilin-1 has been detected in extracellular vesicles.
Cofilin-1 is involved in promoting triple negative breast cancer metastasis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.