Galectin 1 expression is associated with tumor invasion and metastasis in stage IB to IIA cervical cancer

Proteomics of cancer cell lines resistant to microtubule-stabilizing agents

Despite the clinical success of microtubule-interacting agents (MIA), a significant challenge for oncologists is the inability to predict the response of individual patients with cancer to these drugs. In the present study, six cell lines were compared by 2D DIGE proteomics to investigate cellular resistance to the class of MIAs known as microtubule-stabilizing agents (MSA). The human lung cancer cell line A549 was compared with two drug-resistant daughter cell lines, a taxol-resistant cell line (AT12) and an epothilone B (EpoB)-resistant cell line (EpoB40). The ovarian cancer cell line Hey was compared with two drug-resistant daughter cell lines, an EpoB-resistant cell line (EpoB8) and an ixabepilone-resistant cell line (Ixab80). All 2D DIGE results were validated by Western blot analyses. A variety of cytoskeletal and cytoskeleton-associated proteins were differentially expressed in drug-resistant cells. Differential abundance of 14-3-3σ, galectin-1 and phosphorylation of stathmin are worthy of further studies as candidate predictive biomarkers for MSAs. This is especially true for galectin-1, a β-galactose-binding lectin that mediates tumor invasion and metastasis. Galectin-1 was greatly increased in EpoB- and ixabepilone-resistant cells and its suppression caused an increase in drug sensitivity in both drug-sensitive and -resistant Hey cells. Furthermore, the growth medium from resistant Hey cells contained higher levels of galectin-1, suggesting that galectin-1 could play a role in resistance to MSAs.

Unraveling galectin-1 as a novel therapeutic target for cancer

Galectins belong to a family of carbohydrate-binding proteins with an affinity for β-galactosides. Galectin-1 is differentially expressed by various normal and pathologic tissues and displays a wide range of biological activities. In oncology, galectin-1 plays a pivotal role in tumor growth and in the multistep process of invasion, angiogenesis, and metastasis. Evidence indicates that galectin-1 exerts a variety of functions at different steps of tumor progression. Moreover, it has been demonstrated that galectin-1 cellular localization and galectin-1 binding partners depend on tumor localization and stage. Recently, galectin-1 overexpression has been extensively documented in several tumor types and/or in the stroma of cancer cells. Its expression is thought to reflect tumor aggressiveness in several tumor types. Galectin-1 has been identified as a promising drug target using synthetic and natural inhibitors. Preclinical data suggest that galectin-1 inhibition may lead to direct antiproliferative effects in cancer cells as well as antiangiogenic effects in tumors. We provide an up-to-date overview of available data on the role of galectin-1 in different molecular and biochemical pathways involved in human malignancies. One of the major challenges faced in targeting galectin-1 is the translation of current knowledge into the design and development of effective galectin-1 inhibitors in cancer therapy.

Proteomic identification of neoadjuvant chemotherapy-related proteins in bulky stage IB-IIA squamous cervical cancer

OBJECTIVE

The aim of this study was to investigate the effect of neoadjuvant chemotherapy (NAC) on the human squamous cervical cancer using proteomics profiling and to obtain related proteins to NAC exposure and response.

METHODS

Paired samples of early-stage bulky squamous cervical cancer before and after NAC treatment from patients who responded to NAC were obtained and submitted to 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS). The expression and localization of the interesting proteins in additional paired samples were confirmed by Western blot analysis and immunohistochemistry.

RESULTS

The comparison of the proteins present before and after NAC revealed that 116 protein spots were significantly changed. In all, 31 proteins were analyzed by MS, and 15 proteins were upregulated in the cancer tissue after NAC relative to the level before NAC, whereas 16 proteins were downregulated after NAC. The significantly higher expression of peroxiredoxin 1 and significantly lower expression of galectin 1 after NAC treatment were confirmed by Western blot.

CONCLUSIONS

Proteomics can be used to identify the NAC-related proteins in squamous cervical cancer. The change in proteins may be associated with NAC exposure and response, but insight into their relevance requires further study.