Table 2.

Up-regulation of CBS and functional effect of CBS silencing in various cancers. ^a Problematic cell lines, contaminated. Originally thought to originate from a normal fetal liver, shown to be a HeLa derivative [295]. Abbreviations: A549, human lung adenocarcinoma cell line; A2780, human ovarian endometrioid adenocarcinoma cell line; BEAS 2B, normal human bronchial epithelial cell line; BPH-1, prostatic epithelial cells derived from benign human prostatic hyperplasia; Calu-6, human lung adenocarcinoma cell line; CPT, camptothecin; CP20, human papillomavirus-related endocervical adenocarcinoma cell line; DLD-1, human colon adenocarcinoma cell line; DOX, Doxorubicin; DU145, androgen-dependent human prostate cancer cell line; EGI-1, human cholangiocarcinoma cell line; ER, endoplasmic reticulum; FTE188, fallopian tube-derived epithelial cells; GB-D1, human gallbladder carcinoma; GB-H3, human gallbladder carcinoma cell line; GOx, glucose oxidase; HCT116, human colon carcinoma cell line; HepG2, human hepatoblastoma cell line; HMEC, human mammary epithelial cells; HMCL, human myeloma cell line; HOSE, human ovarian surface epithelial cells; HT29, human colon adenocarcinoma cell line; HUCCT-1, human intrahepatic cholangiocarcinoma cell line; HUH-28, human intrahepatic cholangiocarcinoma cell line; H522, human lung adenocarcinoma cell line; H1944, human lung adenocarcinoma cell line; Kuramochi, human high grade ovarian serous adenocarcinoma cell line; LNCaP, androgen-dependent human prostate cancer cells; LoVo, human colon adenocarcinoma cell line; MCF-7, estrogen receptor positive human breast cancer cells; MCF-10 A, normal human breast cells; MDA-MB-468, estrogen receptor negative human breast cancer cells; MFN2, mitofusin-2; MPTP, mitochondrial permeability transition pore; mtDNA, mitochondrial DNA; OSE, normal human ovarian surface epithelial cells; NCM356, normal human colonic epithelial cell line; OVSAHO, human high grade ovarian serous adenocarcinoma cell line; OV90, human ovarian adenocarcinoma cell line; OV167, human ovarian serous adenocarcinoma cell line; OV202, human ovarian serous adenocarcinoma cell line; PPCL, human polyclonal plasmablastic cell line; RCC4, clear cell renal cell carcinoma cell line; ROS, reactive oxygen species; rpL3, ribosomal protein L3; RWPE-1, normal human prostatic peripheral epithelial cells; SHSY5Y, neuroblastoma cell line; SNU 245, human cholangiocarcinoma cell line; SNU 308, human gallbladder carcinoma cell line; SNU 1079, human intrahepatic cholangiocarcinoma cell line; SKOV3, human ovarian serous cystadenocarcinoma cell line; TFK-1, human cholangiocarcinoma cell line; TykNu, human high grade ovarian serous adenocarcinoma cell line; U-87 MG, human glioblastoma-astrocytoma cell line; WPMY-1, normal human prostatic myofibroblast stromal cells; 5-FU, 5-fluorouracil.

Cancer Type	Evidence for CBS Up-regulation	Effect of CBS Silencing	Reference
Biliary tract carcinoma	CBS cRNA hybridization levels measured on oligonucleotide microarray are higher in gallbladder carcinoma, intrahepatic cholangiocarcinoma, distal bile duct carcinomas, EGI-1, TFK-1, HUH28, HUCCT-1, SNU 245, SNU 308, SNU 1079, GB-H3, and GB-D1 cells than in normal extrahepatic biliary and gallbladder epithelial scrapings	Not tested	[287]
Breast cancer	• CBS mRNA levels detected by RT-qPCR and protein levels detected by immunoblotting are both higher in Hs 578T, MCF-7, and MDA-MB-468 cells than in HMEC and MCF-10A cells • CBS protein levels detected by immunohistochemistry are increased with the disease progression on tissue microarray with 60 human breast cancer tissue, and compared to the controls human breast epithelial tissue • CBS protein levels detected by immunoblotting are higher in doxorubicin-resistant MCF-7 cells that in normal MCF-7 cells	• Silencing of CBS in MCF-7 and MDA-MB-468 cells reduces cell viability in the presence of GOx, DOX or activated macrophages • Silencing of CBS in MCF-7 cells reduces xenograft growth in female Balb/c nude mice • Silencing of CBS in MCF-7 and MDA-MB-468 cells causes dilation of the ER and increases cytosolic calcium concentrations • Silencing of CBS in MCF-7 and MDA-MB-468 cells decreases cristae formation and increases vacuole formation in mitochondria, increases MPTP opening, and decreases mitochondrial reserve capacity	[82,289,294]
Colon cancer	• CBS protein levels detected by immunoblotting are higher in human colorectal tumor tissues compared to respective normal mucosa tissues • CBS protein levels detected by immunoblotting are higher in LoVo, HCT116, and HT29 cells compared to NCM356 cells • CBS protein levels detected by immunoblotting are higher in premalignant polyps compared to normal mucosa tissues • CBS protein levels detected by immunohistochemistry are increased in hyperplastic polyps compared to normal crypt cells • CBS protein levels detected by immunohistochemistry on tissue microarray are increased in 40 human colon cancer tissues compared to paired adjacent tissues over 52 colorectal cancer cases • CBS protein levels are increased in the colon cancer cell derived circulating tumor cell population CTC-MCC-41 • The development of multi-drug resistance is associated with an up-regulation of CBS protein in HCT116 cells	Silencing of CBS in HCT116 cells decreases cell proliferation and cellular bioenergetics in vitro and attenuates HCT116 xenograft growth and vascularization in female Balb/c nude mice	[88,290,296,300,302,303,308,309,310,313,315,318]
Glioma	CBS mRNA levels detected by PCR and protein levels detected by immunoblotting are both higher in U-87 MG cells than in SHSY5Y cells	• Not tested	[301]
Liver cancer	• CBS protein levels detected by immunoblotting are higher in HepG2 cells and SMMC-7721 than in HL-7702 cells a • In HepG2 cells stress conditions (e.g., oxidative stress, chemotherapeutics, irradiation) induces cancer cell stemness and multi-drug resistance and this is associated with up-regulation of CBS protein	• Silencing of CBS in SMMC-7721 decreases cell viability and proliferation, increases ROS levels and apoptosis	[291,293,297,312,314]
Lung cancer	• CBS mRNA levels detected by RT-qPCR and CBS protein levels detected by immunoblotting are higher in human primary tumor tissues compared to matched human normal tissues • CBS protein levels detected by immunoblotting are higher in human lung adenocarcinoma tumors than in normal adjacent tissues • CBS protein levels detected by immunoblotting are higher in A549, H522, and H1944 cells compared to BEAS 2B cells	• Down-regulation of CBS by rpL3 enhances Calu-6 cells apoptosis and reduces cell migration and invasion • Transient CBS depletion represses mtDNA repair and increases CPT-induced necrosis in A549 cells	[298,299,319]
Multiple myeloma	• cRNA hybridization levels for CBS, measured on oligonucleotide microarray, are higher in human malignant plasma cells from patients with multiple myeloma than in normal plasma cells • mRNA levels detected by RT-qPCR are higher in HMCL than in PPCL	Not tested	[286]
Ovarian cancer	• Human ovarian tumor tissues exhibited moderate-strong CBS protein expression detected by immunohistochemistry on tissue microarray • CBS mRNA levels detected by RT-qPCR and protein levels detected by immunoblotting are both higher in OV167, OV202, SKOV3, and A2780 cells than in OSE cells • CBS protein levels detected by immunoblotting are higher in OV90, CP20, OVSAHO, Kuramochi, and TykNu and cisplatin-resistant TykNu cells than in OSE, FTE188 and HOSE cells • The ferroptosis inducer small-molecule erastin induced an up-regulation of CBS protein and yielded an erastin-resistant version of ovarian cancer cell lines SKOV3 and OVCA429.	• Silencing of CBS in OV202, SKOV3, A2780, and cisplatin-resistant A2780 decreases total cellular glutathione level and cell proliferation • Silencing of CBS in A2780 cells increases cellular and mitochondrial ROS levels, down-regulates NF-κB, decreases cellular bioenergetics, and sensitizes to cisplatin • Silencing of CBS in cisplatin-resistant A2780 reduces xenograft growth and vascularization, and nodules formation in female nude mice, enhances sensitivity to cisplatin, and decreases MFN2 expression • Silencing of CBS in CP20 and OV90 decreases cell proliferation, mitochondrial membrane potential, and network by promoting mitochondrial fission, cellular bioenergetics and promotes MFN2 degradation • In the erastin-resistant version of ovarian cancer cell lines SKOV3 and OVCA429, CBS silencing induces cell death via induction of ferroptosis	[89,292,306,307,317]
Prostate cancer	• CBS protein levels detected by immunoblotting are higher in BPH-1, LNCaP, and DU145 cells than in RWPE-1 and WPMY-1 cells • CBS protein levels measured by immunofluorescence are higher in LNCaP cells than in RWPE-1 cells	Not tested	[83]
Renal carcinoma	• CBS protein levels detected by immunohistochemistry are increased with the disease progression on tissue microarray, and in 53 renal urothelial carcinomas and 9 renal clear cell carcinomas at Fuhrman grade IV compared to 11 benign renal cortex tissues • cRNA hybridization levels of CBS, measured on oligonucleotide microarray are higher in 2 angiomyolipoma and 3 papillary carcinoma tissues compared to respective unaffected part of kidney tissues	Not tested	[304,305]
Bladder cancer	CBS protein levels were detected in bladder tissue specimens (gallbladder squamous cell/adenosquamous carcinomas and adenocarcinomas) and in the bladder carcinoma cell lines 5637, EJ, and UM-UC-3	Not tested	[311]
Thyroid cancer	Increased CBS protein levels were detected in thyroid carcinomas compared to benign thyroid tissue (but not in thyroid follicular adenomas or oncocytomas)	Not tested	[73]