The purpose of this study is to investigate mechanisms for acquisition of hypoxic tolerance in cancer cells. We cultured RPMI 8226 cell line, which was derived from the peripheral blood of a multiple myeloid patient, in the following three conditions: normoxic, acute and chronic hypoxic conditions. Then, expression levels of the microRNAs and the mRNAs were measured in each condition. The microRNAs whose expression levels changed more than double and the mRNAs whose expression levels changed significantly were detected by pair-wised comparisons. Because a microRNA controls expression levels of mRNAs, we investigated the expression data in the following steps. First, we detected the target mRNAs of a microRNA. From these, we extracted the significantly changed mRNAs. The functions of the target mRNAs were investigated using the DAVID bioinformatics tools. These steps were repeated for all microRNAs. Results of the integrative analysis indicated that negative cell proliferation and angiogenesis were significantly enriched. It is suggested that these functions are related to cancer cells' acquisition of hypoxic tolerance.