Targeting the ubiquitin-proteasome system (UPS)-in particular, the proteasome complex-has emerged as an attractive novel cancer therapy. While several proteasome inhibitors have been successfully approved by the Food and Drug Administration for the treatment of hematological malignancies, the clinical efficacy of these inhibitors is unexpectedly lower in the treatment of solid tumors due to the functional and structural heterogeneity of proteasomes in solid tumors. There are ongoing trials to examine the effectiveness of compound and novel proteasome inhibitors that can target solid tumors either alone or in combination with conventional chemotherapeutic agents. The modest therapeutic efficacy of proteasome inhibitors such as bortezomib in solid malignancies demands further research to clarify the exact effects of these proteasome inhibitors on different proteasomes present in cancer cells. The structural, cellular localization and functional analysis of the proteasome complexes in solid tumors originated from different tissues provides new insights into the diversity of proteasomes' responses to inhibitors. In this study, we used an optimized iodixanol gradient ultracentrifugation to purify a native form of proteasome complexes with their intact associated protein partners enriched within distinct cellular compartments. It is therefore possible to isolate proteasome subcomplexes with far greater resolution than sucrose or glycerol fractionations. We have identified differences in the catalytic activities, subcellular distribution, and inhibitor sensitivity of cytoplasmic proteasomes isolated from human colon, breast, and pancreatic cancer cell lines. Our developed techniques and generated results will serve as a valuable guideline for investigators developing a new generation of proteasome inhibitors as an effective targeted therapy for solid tumors.

Aging is a complex and multifactorial process that increases the risk of various age-related diseases and there are many aging clocks that can accurately predict chronological age, mortality, and health status. These clocks are disconnected and are rarely fit for therapeutic target discovery. In this study, we propose a novel approach to multimodal aging clock we call Precious1GPT utilizing methylation and transcriptomic data for interpretable age prediction and target discovery developed using a transformer-based model and transfer learning for casecontrol classification. While the accuracy of the multimodal transformer is lower within each individual data type compared to the state of art specialized aging clocks based on methylation or transcriptomic data separately it may have higher practical utility for target discovery. This method provides the ability to discover novel therapeutic targets that hypothetically may be able to reverse or accelerate biological age providing a pathway for therapeutic drug discovery and validation using the aging clock. In addition, we provide a list of promising targets annotated using the PandaOmics industrial target discovery platform.

The mTORC2 pathway plays a critical role in promoting tumor progression in human colorectal cancer (CRC). The regulatory mechanisms for this signaling pathway are only partially understood. We previously identi ed UBXN2A as a novel tumor suppressor protein in CRCs and hypothesized that UBXN2A suppresses the mTORC2 pathway, thereby inhibiting CRC growth and metastasis. We rst used murine models to show that haploinsu ciency of UBXN2A signi cantly increases colon tumorigenesis.Induction of UBXN2A reduces AKT phosphorylation downstream of the mTORC2 pathway, which is essential for a plethora of cellular processes, including cell migration. Meanwhile, mTORC1 activities remain unchanged in the presence of UBXN2A. Mechanistic studies revealed that UBXN2A targets Rictor protein, a key component of the mTORC2 complex, for 26S proteasomal degradation. A set of genetic and pharmacological studies showed that UBXN2A regulates cell proliferation, apoptosis, migration, and colon cancer stem cells (CSCs) in CRC. CRC patients with a high level of UBXN2A have signi cantly better survival, and high-grade CRC tissues exhibit decreased UBXN2A protein expression. UBXN2A induction in tumor organoids suppresses the mTORC2 pathway. These ndings provide new insights into the functions of an ubiquitin-like protein by inhibiting a dominant oncogenic pathway in CRC.

The mTORC2 pathway plays a critical role in promoting tumor progression in human colorectal cancer (CRC). The regulatory mechanisms for this signaling pathway are only partially understood. We previously identified UBXN2A as a novel tumor suppressor protein in CRCs and hypothesized that UBXN2A suppresses the mTORC2 pathway, thereby inhibiting CRC growth and metastasis. We first used murine models to show that haploinsufficiency of UBXN2A significantly increases colon tumorigenesis. Induction of UBXN2A reduces AKT phosphorylation downstream of the mTORC2 pathway, which is essential for a plethora of cellular processes, including cell migration. Meanwhile, mTORC1 activities remain unchanged in the presence of UBXN2A. Mechanistic studies revealed that UBXN2A targets Rictor protein, a key component of the mTORC2 complex, for 26S proteasomal degradation. A set of genetic and pharmacological studies showed that UBXN2A regulates cell proliferation, apoptosis, migration, and colon cancer stem cells (CSCs) in CRC. CRC patients with a high level of UBXN2A have significantly better survival, and high-grade CRC tissues exhibit decreased UBXN2A protein expression. UBXN2A induction in tumor organoids suppresses the mTORC2 pathway. These findings provide new insights into the functions of an ubiquitin-like protein by inhibiting a dominant oncogenic pathway in CRC.