先把句子分成不同部分,一段段理解吧
（In subsequent sections） we address new developments （that broaden the scope of the conceptualization）, (describing （in turn）【two enabling characteristics（crucial to the acquisition of the six hallmark capabilities,two new emerging hallmark capabilities, the constitution and signaling interactions of the tumor microenvironment（crucial to cancer phenotypes,） 】)and we finally discuss the new frontier of therapeutic application of these concepts.
所以,主句部分是we address new developments ...and we finally discuss the new frontier.
其他部分都是不同的修饰成分.
developments （that broaden the scope of the conceptualization）括号部分修饰developments
...conceptualization, describing...后面部分【】都是概念描述的内容,相当于the conceptualization that describe【作为describe的宾语】