## 1 Introduction  
Despite highly preventable vaccines and cancer screening programs, cervical cancer has become the fourth most common female cancer and cause of cancer death in women worldwide [1]. Although surgery, chemotherapy, and radiation therapy have been developed as the primary treatment methods for early cervical cancer, it remains a challenge to cure women with metastatic or recurrent disease [2]. Additionally, the adverse side effects of chemo- or radiotherapy on patients may lead to other disease risks. Consequently,otherapy, such as targeted therapy or immunotherapy, has recently been focused on as an essential tool against cervical cancer [3, 4]. Therefore, the investigation of the pathogenesis of cervical cancer and identification of critical molecular targets is of great significance for the effective treatment of cervical cancer. MCPIP1, also known as regulatory RNase-1 (Regnase-1) [5], is the most well-studied and well-described member of MCPIP family proteins, which share a common feature: they all contain a PIN domain and a CCCH-type zinc finger domain. The PIN domain, which is a conserved domain located in the N-terminal part of MCPIP1 and confers it the endoribonuclease activity, contains a catalytic pocket composed of conversed acidic residues such as Asp141, Asp225, Asp226, and Asp244 [6]. Single-mutation analysis demonstrated that the transition of the aspartic acid into asparagine at 141 positions (D141N) of MCPIP1 led to a nearly complete loss of its RNase activity [7]. The CCCH zinc finger domain, which prefers to bind RNA by recognizing specific sequences or secondary structures [8], contributes to the recognition and direct binding of MCPIP1 to mRNAs [9]. MCPIP1 has a high affinity for single-stranded RNA (ssRNA), and it generally binds to mRNA in the 3' untranslated region (UTR) and degrades the mRNA in the stem-loop structure [10; 11]. MCPIP1 is initially described as one of the negative regulatory factors in the inflammatory response during the early phase of inflammation [7; 12]. However, emerging studies have demonstrated that the function of MCPIP1 is closely related to tumor-related processes. MCPIP1 may function as a tumor suppressor in clear cell renal cell carcinoma (ccRCC) [13], leukemia [14], squamous cell carcinoma [15], melanoma [16], and triple-negative breast cancer [17], whereas it plays an oncogenic role in glioma [18]. For instance, MCPIP1 inhibits the viability and proliferation of ccRCC and tumor growth in vivo [13]. Moreover, it suppresses tumor vascularization in vivo through endonuclease activity. Mechanically, MCPIP1 degrades the mRNA of C/EBP\(\beta\), a transcription factor regulating the transcription of SDF-1, which cooperates with its receptor, CXCR4, to promote the expression of proangiogenic factors, such as VEGF. Nonetheless, it remains largely unknown about the function of MCPIP1 in cervical cancer. Here, we found that MCPIP1 inhibits cell proliferation and promotes cervical cancer cell apoptosis. Additionally, MCPIP1 suppresses mRNA and protein expression of the apoptotic inhibitor, XIAP, by decreasing its mRNA stability. Mechanically, MCPIP1 may bind to the XIAP mRNA via its CCCH zinc finger domain and degrade the XIAP mRNA via the endonuclease activity coming from its PIN domain. Our study would clarify that MCPIP1 promotes cervical cancer cell apoptosis by suppressing the expression of XIAP, thereby impeding cervical cancer progression. Targeted delivery of exogenous MCPIP1 into tumor microenvironments (TMEs) could help us to elucidate its functional role in cervical cancer. Compared with conventional drug delivery systems, attenuated bacteria, including _Salmonella typhimurium, E. coli_, and _Bifidobacteria_, have been proven to be excellent delivery vectors due to their high tumor specificity, deep tissue penetration, and remote control capacity [19; 20].