Table 3 Classification to nearest shrunken centroids for identification of the most class-discriminating proteins
Acc. Nr. | Protein name | Gene name | log2 fold change (t-test difference) upregulated in poor responder | p value | t-test significant | Functional role |
|---|---|---|---|---|---|---|
P21266 | Glutathione S-transferase Mu 3 | GSTM3 | 2.68 | 7.13E − 07 | * | Uptake and detoxification of endogenous compounds and xenobiotics at the blood brain barrier [80]; many anticancer drugs are substrates for GST and, therefore, overexpression of GST is responsible for resistance to anti-cancer drugs in tumor cell lines [81] |
P61962 | DDB1- and CUL4-associated factor 7 | DCAF7 | 2.06 | 1.11E − 07 | * | Substrate receptor for a ubiquitin-protein ligase complex; involved in the pathway protein ubiquitination; involved in normal and disease skin development [82]; has been shown to function as a scaffold protein for protein complexes involved in kinase signalling [83] |
P62937 | Peptidyl-prolyl cis–trans isomerase A | PPIA | 0.75 | 4.98E − 07 |  | Upregulated in resistant human breast cancer cell line (vs. sensitive cell line) [84]; PPIases accelerate the folding of proteins; catalyzes the cis–trans isomerization of proline imidic peptide bonds in oligopeptides [85] |
Q16864 | V-type proton ATPase subunit F | ATP6V1F | 3.12 | 5.47E − 07 | * | V-ATPases are responsible for acidifying intracellular compartments [86]; an acidic environment leads to inactivation of T cells [56, 57]; supports the hypothesis that resistance is caused by the tumor inactivating immune cells |
Q6FI81 | Anamorsin | CIAPIN1 | 2.46 | 2.38E − 05 |  | Anti-apoptotic effects in the cell; involved in negative control of cell death upon cytokine withdrawal [87]; may participate in breast cancer multi drug resistance (MDR) by regulating MDR1 and P53 expression, changing cell cycle and enhancing the anti-apoptotic capability of cells [88] |
Q6UWP2 | Dehydrogenase/reductase SDR family member 11 | DHRS11 | 2.10 | 1.64E − 07 | * | Involved in estrogen biosynthesis, which is part of steroid biosynthesis [89]; proposed role in sex hormone, neurosteroid, androgen, estrogen and bile acid metabolism; mRNA highly expressed in testis, small intestine, colon, kidney and cancer cell lines [90] |
Q7Z7E8 | Ubiquitin-conjugating enzyme E2 Q1 | UBE2Q1 | 1.80 | 3.14E − 05 |  | Catalyzes the covalent attachment of ubiquitin to other proteins [91]; may function as an oncogene that induces proliferation of cancer cells, and could be a novel diagnostic tool and a potential therapeutic target for colorectal cancer (CRC) [92] |
Q8IVD9 | NudC domain-containing protein 3 | NUDCD3 | 2.42 | 2.78E − 05 |  | Interacts selectively and non-covalently with an unfolded protein; functions to maintain the stability of dynein intermediate chain [93]; depletion of this gene product results in aggregation and degradation of dynein intermediate chain, mislocalization of the dynein complex from kinetochores, spindle microtubules, and spindle poles, and loss of gamma-tubulin from spindle poles [94] |
Q8N4Q0 | Prostaglandin reductase 3 | ZADH2 | 2.48 | 2.44E − 06 | * | Negatively modulates adipogenesis through regulation of PPARγ activity [95]; knockdown of prostaglandin reductase 1 (PTGR1) suppresses prostate cancer cell proliferation by inducing cell cycle arrest and apoptosis [96] |