**4. Acknowledgment**

334 Breast Cancer – Focusing Tumor Microenvironment, Stem Cells and Metastasis

fibrosarcoma, lung, gastric I/II

pancreatic, lung, ovarian I/II

prostate, sarcoma, leukemia <sup>I</sup>

phase

Class In vivo preclinical activity Clinical

Apicidin Melanoma, leukemia

FK-228, FR901228 Melanoma, colon, sarcoma,

MS-275 Leukemia, colorectal, gastric,

CI-994 Colorectal, pancreatic, mammary,

CHAPs Melanoma, lung, stomach, breast

PXD101 Breast, prostate, ovarian, colon,

NSCLC

In summary, Histone modifications provide crucial regulatory functions in the process of gene transcription, and they play very important roles in the proliferation, metastasis, chemotherapy and other aspects of breast cancer, as well as many other human cancers. The reversibility of histone modification makes it could be regarded as one valuable target for

Table 3. Summary of major HDAC inhibitors (Acharya et al., 2005; Laird, 2005).

Depudecin

Cyclic peptides

Benzamides

Scriptaid

Tubacin

JNJ16241199

hydroxamic acid

**3. Conclusion** 

A-161906

Other hybrid compounds

6-(3-Chlorophenylureido)caproic

This work was financially supported by the National Basic Research Program of China (973 Program) (NO. 2009CB825504), the National Natural Science Fundation of China (NO. 31000343), the High School Science & Technology Development Fundation of Tianjin (NO.20090602) and the Scientific Research Launch Fund for Introduction of Talents into Tianjin University of Science & Technology (No. 20080414).
