# CA IX Inhibition by a Sulfonamide Compound: A Therapeutic Approach Against Breast Cancer

## TL;DR

This study explores a sulfonamide compound, MMH-I, that targets CA IX to inhibit breast cancer growth and induce apoptosis in both lab and animal models.

## Contribution

The study demonstrates the in vivo and metabolic efficacy of MMH-I as a CA IX-targeted therapeutic for breast cancer.

## Key findings

- MMH-I significantly reduced tumor volume and induced apoptosis in breast cancer cells.
- The compound altered cancer-related gene expression and metabolic profiles in tumor tissues.
- Combination therapy with MMH-I and 5-Fluorouracil showed synergistic effects in CA IX-expressing breast cancer models.

## Abstract

Carbonic anhydrase IX (CA IX) is overexpressed in many solid tumors, contributing to cancer cell proliferation, survival, invasion, and metastasis. Sulfonamide‐based compounds have emerged as potential anticancer agents by inhibiting this enzyme. In this study, we investigated the anticancer potential of a previously synthesized sulfonamide derivative, MMH‐I, focusing on its CA IX‐targeted activity and therapeutic efficacy in both in vitro and in vivo models of breast cancer. Cytotoxicity was assessed using MTT assays in 4T1 breast cancer cells, while apoptosis was evaluated by acridine orange/ethidium bromide staining and Annexin V detection. In vivo studies analyzed tumor tissues for CA IX expression, as well as Vimentin, E‐Cadherin, and Caspase‐3 levels. H&E staining and plasma metabolomic analysis were performed to assess tissue morphology and metabolic alterations. The compound significantly reduced tumor volume, induced apoptosis, and altered cancer‐related gene expression and metabolic profiles. Overall, this study provides a detailed in vivo and metabolic evaluation of MMH‐I in breast cancer, highlighting its potential as a CA IX–targeted therapeutic candidate and supporting further investigation of sulfonamide‐based combination strategies against hypoxic tumors.

Synergistic Efficacy of MMH‐I and 5‐Fluorouracil Combination Therapy in CA IX‐Expressing Breast Cancer Models: Pathological and Metabolic Insights.