Correlation between CA12 and TFF3 and their prediction value of neoadjuvant chemotherapy response in breast cancer

Compared with other molecular subtypes, hormone receptor-positive breast cancer often shows worse neoadjuvant chemotherapy efficacy. This study aims to explore the relationship between the oestrogen receptor (ER)-related genes carbonic anhydrase 12 (CA12) and trefoil factor 3 (TFF3) and their predictive value of neoadjuvant chemotherapy for breast cancer.

We investigated the relationships between CA12, TFF3 and ER status and their predictive value of anthracycline-taxane neoadjuvant chemotherapy in 115 female breast cancer patients via real-time polymerase chain reaction (RT-PCR) and 4 GEO datasets: GSE41998, GSE25065, GSE20194 and GSE20271. Then, the effects of CA12 and TFF3 on the chemotherapy drugs doxorubicin and docetaxel were verified in vitro in the breast cancer cell lines MCF-7 and BT474.

The GEO datasets and RT-PCR results showed that the relative expression of both CA12 and TFF3 was higher in oestrogen receptor-positive samples compared with the other samples (p < 0.05). CA12 was significantly correlated with TFF3 (p < 0.05). In MCF-7 cells, inhibition of TFF3 induced downregulation of CA12 and ESR1 (p < 0.05) at both the mRNA and the protein levels, while inhibition of CA12 also downregulated TFF3 and ESR1 (p < 0.05). In BT474 cells, inhibition of TFF3 downregulated CA12 and ESR1 (p < 0.05) at both the mRNA and the protein levels, while inhibition of CA12 led to slight upregulation of TFF3 and ESR1 (p > 0.05). Moreover, GEO datasets and RT-PCR results showed that CA12 and TFF3 were more highly expressed in nonpathological complete response (non-pCR) samples than in pCR samples (p < 0.05). Cell viability assays of MCF-7 and BT474 cells showed that inhibiting CA12 and TFF3 could enhance sensitivity to doxorubicin and docetaxel (p < 0.05).

CA12 and TFF3 were correlated with each other, and their high expression might explain the worse efficacy of neoadjuvant chemotherapy in oestrogen receptor-positive breast cancer patients.