Rapidly proliferative processes in mammalian tissues including tumorigenesis and embryogenesis rely on the glycolytic pathway for energy and biosynthetic precursors. The enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3) plays an important regulatory role in glycolysis by activating the key rate-limiting glycolytic enzyme, 6-phosphofructo-1-kinase (PFK-1). We have previously determined that decreased PFKFB3 expression reduced glycolysis and growth in transformed cells in vitro and suppressed xenograft growth in vivo. In earlier studies, we created a constitutive knockout mouse to interrogate the function of PFKFB3 in vivo but failed to generate homozygous offspring due to the requirement for PFKFB3 for embryogenesis. We have now developed a novel transgenic mouse model that exhibits inducible homozygous pan-tissuePfkfb3gene deletion (Pfkfb3fl/fl). We have inducedPfkfb3genomic deletion in these mice and found that it effectively decreased PFKFB3 expression and activity. To evaluate the functional consequences ofPfkfb3deletion in vivo, we crossed Cre-bearingPfkfb3fl/flmice with oncogene-driven tumor models and found thatPfkfb3deletion markedly decreased their glucose uptake and growth. In summary, our studies reveal a critical regulatory function for PFKFB3 in glycolysis and tumorigenesis in vivo and characterize an effective and powerful model for further investigation of its role in multiple biological processes.
哺乳动物组织中包括肿瘤发生和胚胎发育在内的快速增殖过程，均依赖糖酵解途径获取能量和生物合成前体。6-磷酸果糖-2-激酶/果糖-2,6-二磷酸酶-3（PFKFB3）通过激活关键限速糖酵解酶6-磷酸果糖-1-激酶（PFK-1），在糖酵解调控中发挥重要作用。我们前期研究发现，降低PFKFB3表达可减少转化细胞的体外糖酵解与生长，并抑制体内异种移植瘤的生长。在早期研究中，我们构建了组成性基因敲除小鼠以探究PFKFB3的体内功能，但由于胚胎发育对PFKFB3的需求，未能获得纯合子后代。目前我们成功建立了新型转基因小鼠模型，该模型可实现诱导型纯合子全组织Pfkfb3基因缺失（Pfkfb3fl/fl）。通过诱导该模型小鼠的Pfkfb3基因组缺失，我们发现其能有效降低PFKFB3的表达与活性。为评估体内Pfkfb3缺失的功能性后果，我们将携带Cre的Pfkfb3fl/fl小鼠与癌基因驱动的肿瘤模型进行杂交，发现Pfkfb3缺失能显著降低其葡萄糖摄取与肿瘤生长。综上所述，本研究揭示了PFKFB3在体内糖酵解和肿瘤发生中的关键调控功能，并构建了高效有力的模型体系，为深入探究其在多种生物过程中的作用奠定了基础。
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