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We are happy to hear that our article has attracted attention and interest of other research groups. We are happy to discuss the concerns that they have raised regarding our manuscript. Below, we have provided a point-by-point response to the thoughtful questions presented by Dr. Yang's group.

First, in our study, we did not observe microRNA-145 (miR-145) deregulation in 10-month-old transgenic mice samples using microRNA arrays. Thus, we did not concentrate on the role of miR-145 in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) in our subsequent experiments. In fact, there are a number of studies involving the inconsistent expression profiles of miR-143 and miR-145 in cancers, such as in pancreatic cancer and colorectal cancer.1, 2 Moreover, miR-143 plays roles in adipocyte differentiation, in a process that was independent of miR-145.3 As for miR-145, it has p53REs (p53 response elements) in the miR-145 promoter that can be induced by p53, whereas miR-143 lacks these putative p53REs in the 10-kilobase DNA region upstream of has-miR-143 (http://jaspar.genereg.net), which means p53 has no direct impact on its expression, consistent with the report by He et al.4

Second, Dr. Yang asks if miR-143 is directly transcribed by nuclear factor κB (NF-κB) and kindly suggested performing a promoter-reporter assay to further support our conclusion. First, we believe that these questions are the precise questions that we were interested in answering from the very beginning of our study. Due to the word limits and in the interest of preparing a succinct manuscript, we did experiments to demonstrate that miR-143 is directly transcribed by the transcription factor NF-κB in accordance with the study of Li et al.5 From a methodological perspective, it would certainly be more convincing if we applied additional assays, such as a promoter-reporter assay or electrophoretic mobility-shift assay. Moreover, we certainly believe that there may be different indirect regulatory forces acting on hepatitis B x antigen (HBx), NF-κB, and miR-143 due to the multiple roles of NF-κB and HBx in HCC development.

Third, Dr.Yang asked about the relationship of HBx, mir-143, and fibronectin type III domain containing 3B (FNDC3B) expression patterns in HBV-related HCC. We have described these patterns in our article as follows: “HBV-negative HCC without metastasis, n = 5 …” Therefore, HBx is positive in all patients with HCC who have HBV infection; HBx is negative in all patients diagnosed without HBV infection. We have also explained miR-143 expression in Fig. 1B and FNDC3B expression in Fig. 4F.

References

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  • 1
    Bloomston M, Frankel WL, Petrocca F, Volinia S, Alder H, Hagan JP, et al. MicroRNA expression patterns to differentiate pancreatic adenocarcinoma from normal pancreas and chronic pancreatitis. JAMA 2007; 297: 19011908.
  • 2
    Bandres E, Cubedo E, Agirre X, Malumbres R, Zarate R, Ramirez N, et al. Identification by real-time PCR of 13 mature microRNAs differentially expressed in colorectal cancer and non-tumoral tissues. Mol Cancer 2006; 5: 29.
  • 3
    Esau C, Kang X, Peralta E, Hanson E, Marcusson EG, Ravichandran LV, et al. MicroRNA-143 regulates adipocyte differentiation. J Biol Chem 2004; 279: 5236152365.
  • 4
    He L, He X, Lim LP, de Stanchina E, Xuan Z, Liang Y, et al. A microRNA component of the p53 tumour suppressor network. Nature 2007; 447: 11301134.
  • 5
    Ma L, Teruya-Feldstein J, Weinberg RA. Tumour invasion and metastasis initiated by microRNA-10b in breast cancer. Nature 2007; 449: 682688.

Xiaoying Zhang*, Shuhan Sun*, * Department of Medical Genetics, Second Military Medical University, Shanghai, China.